CN109160644B

CN109160644B - Online cleaning method and system for viscose waste liquid environment-friendly treatment system

Info

Publication number: CN109160644B
Application number: CN201811310506.7A
Authority: CN
Inventors: 邓传东; 贺敏; 夏长林; 徐绍贤; 王云
Original assignee: Yibin Grace Group Co Ltd; Yibin Haisite Fiber Co Ltd
Current assignee: Yibin Grace Group Co Ltd; Yibin Haisite Fiber Co Ltd
Priority date: 2018-11-06
Filing date: 2018-11-06
Publication date: 2023-08-22
Anticipated expiration: 2038-11-06
Also published as: CN109160644A

Abstract

The invention relates to an online cleaning method and an online cleaning system for an environment-friendly viscose waste liquid treatment system, and belongs to the technical field of waste liquid treatment in viscose fiber production. The system comprises a main controller, a DCS controller, a blending tank, a coarse filtering device, a fine filtering device, a resin tower, a bipolar membrane device, a nanofiltration device and other cleaning systems which are all connected with the DCS controller; each cleaning system is respectively connected with a sulfuric acid tank, a sodium hydroxide tank and/or a desalting water tank, and the viscose waste liquid environment-friendly treatment system is judged whether to meet cleaning conditions or not through the on-line detection of a master controller, so that the point to be cleaned is selected; the point to be cleaned is cleaned through switching of a control valve and a delivery pump; finally, collecting the sewage of each cleaning system. The invention realizes on-line automatic cleaning and zero emission, and effectively ensures stable, smooth and controllable performance of the environment-friendly treatment of the viscose waste liquid.

Description

Online cleaning method and system for viscose waste liquid environment-friendly treatment system

Technical Field

The invention relates to an online cleaning method and an online cleaning system, in particular to an online cleaning method and an online cleaning system for an environment-friendly viscose waste liquid treatment system, and belongs to the technical field of waste liquid treatment in viscose fiber production.

Background

The viscose is a chemical fiber which is processed by using polymer materials such as wood pulp and cotton pulp containing natural cellulose through chemical and mechanical methods, is the type of chemical fiber which has the closest performance to natural fiber clothing, has the characteristics of soft hand feeling, moisture absorption and ventilation, elegant hanging, bright dyeing, static resistance, easiness in textile processing and the like, is derived from the natural source, is superior to the natural regenerated cellulose fiber, and is one of important materials of textile industry raw materials. At present, about 40 viscose fiber enterprises in China produce common viscose fibers (filaments and short fibers) and strong filaments, and high-wet-modulus type fibers and viscose fibers with special properties.

In the production process of viscose fiber, a large amount of chemical raw materials are needed, a large amount of wastewater is generated, and the wastewater contains sulfuric acid, zinc sulfate, carbon disulfide, cellulose, soluble organic matters and the like, so that the wastewater is very harmful to the environment, and is one of main pollution sources in the textile industry.

Wherein, in the viscose fiber forming process, viscose is acted with an acidic coagulating bath to neutralize alkali, and cellulose sodium sulfonate is decomposed to regenerate hydrated cellulose, cellulose sulfonate, free NaOH and Na generated by side reaction in the viscose in the process ₂ CS ₃ Side reaction products such as polysulfide and the like can react with sulfuric acid in the coagulating bath to generate sodium sulfate. The viscose fiber production comprises an acid bath process consuming sulfuric acid, and also comprises a pulp dipping process consuming sodium hydroxide, an alkali cellulose sulfonate dissolving process, an exhaust gas absorbing process, a refining press-washing process and an acid water neutralization treatment process.

The main functions of sodium sulfate in the coagulating bath are to promote the coagulation of viscose liquid flow and inhibit the dissociation of sulfuric acid, so that the regeneration speed of cellulose sulfonate is delayed, the concentration of sodium sulfate in the coagulating bath is increased, the spinning operation is easier, the yarn bundles are not easy to break, the dissociation degree of sulfuric acid can be reduced, the yarn bundles still have a certain residual esterification degree when leaving the coagulating bath, but the sodium sulfate in the coagulating bath is not too high, otherwise, the fiber is too fast to coagulate, a fine structure cannot be formed, coarse crystal particles are generated, and the inner layer and the outer layer of the fiber are also uneven.

In the spinning process, the content of sodium sulfate in the coagulating bath is continuously increased, so that the coagulating bath cannot meet the process requirement, if the total amount of the coagulating bath is increased and cannot be stored only by adding the consumed raw materials in the coagulating bath to supplement the concentration of the raw materials for recycling, the coagulating bath can only be discharged in a timed and quantitative manner, and acid, salt, metal ions and the like in the coagulating bath can cause serious environmental pollution, bring huge pressure to sewage treatment and cause huge waste of resources. And the redundant sodium sulfate in the acid bath is subjected to high-temperature crystallization, sodium sulfate crystals are separated, so that the content of sodium sulfate in the acid bath meets the process requirement, the acid bath is not required to be balanced by discharging acid every day, the acid is directly supplied to a spinning workshop for continuous use after feeding, the acid discharge can be reduced, anhydrous sodium sulfate is produced, and the environmental protection pressure is reduced, but the anhydrous sodium sulfate produced by the high-temperature crystallization of sodium sulfate in the coagulating bath contains more impurities and has low added value, so that economic benefit cannot be produced, a large amount of solid salt cannot be treated, and certain pressure is brought to the environmental protection.

The national bureau of knowing discloses a patent document with publication number CN101343124, named "recycling tank-based viscose waste liquid environmental protection treatment device" in 2009, 01 and 14 days; the national bureau discloses a patent document with a publication number of CN206666261U, named as a viscose acidic wastewater treatment device, in 2017, 11 and 24; the national bureau discloses a patent document with a publication number of CN103342433A on the 10 th 09 th 2013, and the name of the patent document is a method for recycling acid and alkali from viscose sodium sulfate waste liquid by adopting a bipolar membrane electrodialysis method; the national bureau discloses a patent document with publication number of CN103388198A, named "a method for preparing acid and alkali from viscose sodium sulfate waste liquid by bipolar membrane electrodialysis method" in 2013, 11 and 13; and the national bureau discloses a patent document with publication number CN103351041a, named "electrodialysis alkali recovery process in viscose fiber production", at 10/16 of 2013.

There are also the following problems:

at present, no mature technology such as a cleaning method and a device which are specially designed for the viscose waste liquid treatment device exists, and the cleaning quality of the viscose waste liquid treatment device cannot be ensured, so that the viscose waste liquid treatment efficiency is low and the quality is poor; after the viscose waste liquid is treated, there is also waste discharge, which is not beneficial to environmental protection production; after the recovery of sulfuric acid, sodium hydroxide and dilute sodium sulfate, the purity and concentration of the viscose waste liquid can not meet the actual requirements, namely, the impurities are more, the concentration is small, and the product quality is greatly influenced after the viscose waste liquid returns to the viscose fiber production process, so that a cleaning method and a cleaning device designed for the viscose waste liquid treatment device are needed.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, and provides an online cleaning method and an online cleaning system for an environment-friendly viscose waste liquid treatment system. According to the invention, through online detection of the master controller, the DCS controller performs online control, and corresponding cleaning procedures, cleaning agents, nursing and the like are set on the premise of accurate selection of cleaning sites, accurate judgment of cleaning conditions, limitation of cleaning indexes and the like; the invention not only can realize on-line automatic cleaning, has low labor cost and low labor intensity, but also can realize the centralized recovery treatment of the cleaning waste liquid, realize zero emission and meet the environmental protection requirement; meanwhile, the environment-friendly treatment of the viscose waste liquid is effectively ensured to be stable, smooth and controllable.

In order to achieve the technical purpose, the following technical scheme is provided:

an online cleaning system of an environment-friendly viscose waste liquid treatment system comprises a main controller for online detection, a DCS controller connected with the main controller, and a blending tank cleaning system, a coarse filter device cleaning system, a fine filter device cleaning system, a resin tower cleaning system, a bipolar membrane device cleaning system, a nanofiltration device cleaning system, a reverse osmosis device cleaning system and an acid salt separation device cleaning system which are all connected with the DCS controller;

Blending tank cleaning system: the device comprises a sulfuric acid tank and a desalination water tank which are connected with a blending tank, wherein the sulfuric acid tank is connected with the blending tank through a pickling pipe, and a control valve and a delivery pump are arranged on the pickling pipe; the desalting water tank is connected with the blending tank through a desalting water pipe, and a control valve and a delivery pump are arranged on the desalting water pipe;

coarse filtration device cleaning system: the device comprises a sulfuric acid tank and a desalting water tank which are connected with a coarse filtration device, wherein the sulfuric acid tank is connected with the coarse filtration device through an acid washing pipe, and a control valve and a delivery pump are arranged on the acid pipe; the desalting water tank is connected with the coarse filtering device through a desalting water pipe, and a control valve and a delivery pump are arranged on the desalting water pipe;

the cleaning system of the fine filtering device comprises: comprises a sulfuric acid tank and a desalting water tank which are connected with a fine filtering device, wherein the sulfuric acid tank is connected with the fine filtering device through a pickling pipe, and a control valve and a delivery pump are arranged on the pickling pipe; the desalting water tank is connected with the fine filtering device through a desalting water pipe, and a control valve and a delivery pump are arranged on the desalting water pipe;

resin tower cleaning system: comprises a sulfuric acid tank, a sodium hydroxide tank and a desalting water tank which are connected with a resin tower, wherein the sulfuric acid tank is connected with the resin tower through a pickling pipe, and the pickling pipe is provided with a control valve and a delivery pump; the sodium hydroxide tank is connected with the resin tower through an alkaline washing pipe, and a control valve and a delivery pump are arranged on the alkaline washing pipe; the desalting water tank is connected with the resin tower through a desalting water pipe, and a control valve and a conveying pump are arranged on the desalting water pipe;

Bipolar membrane device cleaning system: the device comprises a sulfuric acid tank and a desalting water tank which are connected with a bipolar membrane device, wherein the sulfuric acid tank is connected with the bipolar membrane device through a pickling pipe, and a control valve and a delivery pump are arranged on the pickling pipe; the desalting water tank is connected with the bipolar membrane device through a desalting water pipe, and a control valve and a delivery pump are arranged on the desalting water pipe;

the nanofiltration device cleaning system comprises a return pipe connected with the nanofiltration device, the other end of the return pipe is connected with a filtrate tank, a control valve and a delivery pump are arranged on the return pipe, the filtrate tank is connected with a filtrate outlet of the nanofiltration device, and the filtrate tank is used for collecting filtrate in the nanofiltration device;

reverse osmosis unit cleaning system: the device comprises a desalination water tank connected with a reverse osmosis device, wherein the desalination water tank is connected with the reverse osmosis device through a desalination water pipe, and a control valve and a delivery pump are arranged on the desalination water pipe;

acid salt separation device cleaning system: the salt removing device comprises a salt removing water tank connected with a salt separating device, wherein the salt removing water tank is connected with the salt separating device through a salt removing water pipe, and a control valve and a conveying pump are arranged on the salt removing water pipe.

Further, the blending tank, the coarse filtration device, the fine filtration device, the resin tower, the bipolar membrane device, the nanofiltration device, the reverse osmosis device and the acid salt separation device are all connected with a sewage pipe, the sewage pipe is connected with a collecting tank, and a delivery pump is arranged on the sewage pipe.

Further, at least 3 resin towers are connected through a conveying pipe, and a switching valve and a zinc ion detector are arranged on the conveying pipe.

Further, the viscose waste liquid environment-friendly treatment system comprises a centrifuge, a transfer tank, a blending tank, a coarse filtering device, a fine filtering device, a resin tower, a circulating tank and a bipolar membrane device, wherein the transfer tank is arranged at one side of a station of the centrifuge; the transfer tank is connected with a desalted water storage tank and is connected with the blending tank; the blending tank is connected with a temperature-adjusting heat exchanger, a pH-adjusting alkali storage tank and a sodium sulfate concentration-adjusting brine storage tank, and is connected with the coarse filtering device; the coarse filtering device is connected with the fine filtering device, the fine filtering device is connected with the resin tower, the resin tower is connected with the bipolar membrane device through the circulating tank, and an independent circulating passage is formed between the circulating tank and the bipolar membrane device;

the acid outlet of the bipolar membrane device is connected with a reverse osmosis device, the concentrated acid outlet of the reverse osmosis device is directly connected with an acid station acid storage tank in the viscose fiber production process through an acid pipe, and the permeate outlet of the reverse osmosis device is directly connected with the bipolar membrane device;

the alkali outlet of the bipolar membrane device is connected with a nanofiltration device, the filtrate outlet of the nanofiltration device is directly connected with a stock solution storage tank in the viscose fiber production process through an alkali pipe, and the concentrate outlet of the nanofiltration device is directly connected with a blending tank through a salt pipe;

The salt outlet of the bipolar membrane device is connected with an acid salt separating device, the acid outlet of the acid salt separating device is directly connected with an acid station acid storage tank in the viscose fiber production process through an acid pipe, and the salt outlet of the acid salt separating device is directly connected with a middle transfer tank through a salt pipe.

Further, the coarse filter device is a bag filter with the aperture of 10-15 mu m, and the fine filter device is an ultrafilter with the aperture of 0.01-0.05 mu m.

Further, the detection range of the zinc ion detector is 0-3 ppm.

An online cleaning method of an environment-friendly viscose waste liquid treatment system comprises the following steps:

A. adopting a master controller to carry out on-line detection on an environment-friendly viscose waste liquid treatment system, judging whether a cleaning system of a blending tank, a cleaning system of a coarse filtering device, a cleaning system of a fine filtering device, a cleaning system of a resin tower, a cleaning system of a bipolar membrane device, a cleaning system of a nanofiltration device, a cleaning system of a reverse osmosis device or a cleaning system of an acid salt separation device meets cleaning conditions, and then selecting a point to be cleaned;

B. the DCS controller is communicated with the blending tank cleaning system, the coarse filter device cleaning system, the fine filter device cleaning system, the resin tower cleaning system, the bipolar membrane device cleaning system, the nanofiltration device cleaning system, the reverse osmosis device cleaning system or the acid salt separation device cleaning system, and the point to be cleaned is cleaned by switching a control valve and a conveying pump;

C. After the cleaning of the cleaning point is finished, the generated sewage is conveyed to a collecting tank through a sewage pipe for the next treatment.

Further, in step A, the process comprises,

the conditions for cleaning the blending tank comprise: the precipitation amount is 0.6-1 t;

the conditions under which the coarse filtration device needs to be cleaned include: the filtering pressure is more than 0.5MPa;

the conditions under which the fine filtration device needs to be cleaned include: the filtrate flux decreased by 30%;

the conditions for cleaning the resin tower clear comprise: zinc ions in the liquid are more than 1ppm;

conditions under which the bipolar membrane device requires cleaning include: the voltage of the membrane stack mechanism is more than 270V;

the conditions under which the nanofiltration device needs to be cleaned include: the flux of the nanofiltration membrane is reduced by 30%;

the conditions under which the reverse osmosis device needs to be cleaned include: the reverse osmosis flux is reduced by 30%;

the conditions under which the acid salt separation device needs to be cleaned include: the acid content in the salt solution is more than 1g/L.

Further, in step B,

when the blending tank is cleaned, the blending tank is cleaned for 1 to 2 hours under the conditions that the temperature is 35 to 40 ℃ and the pH is less than 2; the method specifically comprises the following steps: firstly, sulfuric acid with the concentration of 8 percent is introduced into a blending tank through a sulfuric acid tank for 10-12 m, and the mixture is subjected to the steps of cleaning, circulation and discharge; introducing desalted water into the blending tank through the desalted water tank for 5-10 m, flushing and discharging;

When the coarse filter device is cleaned, the coarse filter device is cleaned for 1 to 2 hours under the conditions that the temperature is 30 to 40 ℃ and the pH value is less than 2; the method specifically comprises the following steps: firstly, sulfuric acid with the concentration of 6-8% is introduced into a coarse filtering device through a sulfuric acid tank for 1-2 m for cleaning and discharging; introducing desalted water into the coarse filtering device through a desalted water tank for 2-3 m, cleaning and discharging;

when the fine filtering device is cleaned, the fine filtering device is cleaned for 0.5 to 1 hour under the conditions that the temperature is 40 to 50 ℃ and the pH is less than 2; the method specifically comprises the following steps: firstly, sulfuric acid with the concentration of 0.5 percent is introduced into a fine filtering device through a sulfuric acid tank for 5-10 m for cleaning, circulating and discharging; introducing desalted water into the fine filtering device through a desalted water tank for 1-2 m, cleaning and discharging;

when the resin tower is cleaned, cleaning is carried out for 25-30 h under the normal temperature condition; the method specifically comprises the following steps: firstly, introducing desalted water into a resin tower through a desalted water tank for 60-80 m, flushing and discharging; secondly, introducing sulfuric acid with the concentration of 8% into the resin tower for 20-30 m through a sulfuric acid tank, cleaning, circulating and discharging; thirdly, introducing desalted water into the resin tower through a desalted water tank for 40-50 m for a period of time, flushing to neutrality, and discharging; finally, introducing sodium hydroxide with the concentration of 8% into the resin tower for 7-10 m through a sodium hydroxide tank, circularly discharging, and keeping the pH value of the internal environment of the resin tower at 8-9;

When the bipolar membrane device is cleaned, the bipolar membrane device is cleaned for 5 to 6 hours under the conditions that the temperature is 30 to 35 ℃, the pH is less than 2 and the pressure is 0.05 Mpa; the method specifically comprises the following steps: firstly, introducing desalted water into a bipolar membrane device through a desalted water tank for 8-10 m, flushing and discharging; then 8-10 m of sulfuric acid with the concentration of 0.5-2% is introduced into the bipolar membrane device through a sulfuric acid tank, and the bipolar membrane device is circularly soaked, cleaned and discharged; finally, introducing desalted water into the bipolar membrane device through a desalted water tank for 8-10 m, flushing and discharging;

when the nanofiltration device is cleaned, 5-10 m of filtrate in a filtrate outlet of the nanofiltration device is conveyed back to the nanofiltration device through a return pipe under the normal temperature condition, and the nanofiltration device is cleaned for 0.5-1 h;

when the reverse osmosis device is cleaned, desalted water is introduced into the reverse osmosis device for 15-20 m through a desalted water tank under the conditions of normal temperature and pressure of 3Mpa, and the reverse osmosis device is cleaned for 0.5-1 h;

when the acid salt separating device is cleaned, desalted water is introduced into the acid salt separating device through a desalted water tank for 15-20 m for cleaning for 0.5-1 h under the normal temperature condition.

Further, the normal temperature is a temperature commonly referred to in the chemical industry.

Further, in step C, after the cleaning is completed, the index satisfies:

The precipitation amount in the blending tank is less than 0.01t;

the zinc ion in the coarse filtration device is less than 10ppm;

the filtrate flux of the fine filtering device is more than 98%;

zinc ions in the liquid of the resin tower are less than 1ppm;

the voltage of a membrane stack mechanism in the bipolar membrane device is 200-270V;

the flux of the nanofiltration membrane in the nanofiltration device is more than 98 percent;

the reverse osmosis flux in the reverse osmosis device is more than 98 percent;

the acid content of the salt solution in the acid salt separation device is lower than 0.1g/L.

Further, the viscose waste liquid comprises sodium sulfate with the concentration of 200-300 g/L, zinc sulfate with the concentration of 0.1-1 g/L and sulfuric acid with the concentration of 5-10 g/L.

Further, in the step C, after the cleaning is completed,

the sewage generated by the blending tank comprises 8.1 to 13.5 weight percent of zinc sulfate and 0 to 3.3 and wt weight percent of sulfuric acid;

the sewage generated by the coarse filtering device comprises 60-80 and wt percent of zinc sulfate.

The sewage generated by the fine filtering device comprises 0.5wt.% zinc sulfate;

the wastewater produced by the resin tower comprises 0.08wt.% zinc sulfate and 7 wt wt.% sulfuric acid;

the sewage generated by the bipolar membrane device comprises 0.01wt.% zinc sulfate and 0.4-0.9 wt.% sulfuric acid;

The sewage generated by the nanofiltration device comprises 0.2wt.% of sodium sulfate and 4.5-8 wt.% of sodium hydroxide;

the sewage generated by the reverse osmosis device comprises 0.1wt.% sulfuric acid;

the sewage generated by the acid salt separation device comprises 5-15 g/L sulfuric acid.

By adopting the technical scheme, the beneficial technical effects brought are as follows:

1) In the invention, the cleaning system is automatic online cleaning, so that the labor cost and the labor intensity are low;

2) The DCS system has high control reliability and stable operation process;

3) Automatic online cleaning, but the waste cleaning liquid automatic collection reduces and reveal, carries out concentrated recovery processing with the waste cleaning liquid, realizes zero release.

Drawings

FIG. 1 is a block diagram of a logical connection of the present invention;

FIG. 2 is a workflow diagram of the present invention;

FIG. 3 is a block diagram of the logical connections of the viscose waste liquid environmental protection treatment system of the present invention;

FIG. 4 is a flow chart of the environment-friendly viscose waste liquid treatment system;

FIG. 5 is a schematic diagram of the logical connections between resin columns in the present invention;

FIG. 6 is a schematic diagram of the logical connections of the surge tank cleaning system of the present invention;

FIG. 7 is a schematic diagram of the logical connections of the resin column cleaning system of the present invention;

FIG. 8 is a schematic diagram of the logical connections of the nanofiltration device cleaning system of the present invention;

FIG. 9 is a schematic diagram of the logical connections of the reverse osmosis unit cleaning system of the present invention;

wherein, in the figure: 1. centrifuge, 2, transfer tank, 3, blending tank, 4, coarse filtration device, 5, fine filtration device, 6, resin tower, 7, bipolar membrane device, 8, circulation tank, 9, reverse osmosis device, 10, nanofiltration device, 11, acid salt separation device, 12, desalted water storage tank, 13, salt water storage tank, 14, heat exchanger, 15, alkali storage tank, 16, conveying pipe, 17, switching valve, 18, zinc ion detector;

19. the device comprises a main controller, 20, a DCS controller, 21, a sulfuric acid tank, 22, a desalination water tank, 23, a sodium hydroxide tank, 24, an acid washing pipe, 25, an alkali washing pipe, 26, a desalination water pipe, 27, a control valve, 28, a delivery pump, 29, a return pipe, 30, a sewage pipe, 31 and a collection tank.

Detailed Description

In the following, it is obvious that the embodiments described are only some embodiments of the present invention, but not all embodiments, by clearly and completely describing the technical solutions in the embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

An online cleaning system of an environment-friendly viscose waste liquid treatment system comprises a main controller 19 for online detection, a DCS controller 20 connected with the main controller 19, and a blending tank cleaning system, a coarse filter device cleaning system, a fine filter device cleaning system, a resin tower cleaning system, a bipolar membrane device cleaning system, a nanofiltration device cleaning system, a reverse osmosis device cleaning system and an acid salt separation device cleaning system which are all connected with the DCS controller 20;

blending tank cleaning system: comprises a sulfuric acid tank 21 and a desalination water tank 22 which are connected with a blending tank 3, wherein the sulfuric acid tank 21 is connected with the blending tank 3 through a pickling pipe 24, and the pickling pipe 24 is provided with a control valve 27 and a delivery pump 28; the desalting water tank 22 is connected with the blending tank 3 through a desalting water pipe 26, and a control valve 27 and a delivery pump 28 are arranged on the desalting water pipe 26;

coarse filtration device cleaning system: comprises a sulfuric acid tank 21 and a desalination water tank 22 which are connected with a coarse filtration device 4, wherein the sulfuric acid tank 21 is connected with the coarse filtration device 4 through an acid washing pipe 24, and a control valve 27 and a delivery pump 28 are arranged on the acid pipe; the desalination water tank 22 is connected with the coarse filtration device 4 through a desalination water pipe 26, and a control valve 27 and a delivery pump 28 are arranged on the desalination water pipe 26;

the cleaning system of the fine filtering device comprises: comprises a sulfuric acid tank 21 and a desalination water tank 22 which are connected with a fine filtration device 5, wherein the sulfuric acid tank 21 is connected with the fine filtration device 5 through a pickling pipe 24, and a control valve 27 and a delivery pump 28 are arranged on the pickling pipe 24; the desalination water tank 22 is connected with the fine filtration device 5 through a desalination water pipe 26, and a control valve 27 and a delivery pump 28 are arranged on the desalination water pipe 26;

Resin tower cleaning system: comprises a sulfuric acid tank 21, a sodium hydroxide tank 23 and a desalting water tank 22 which are connected with a resin tower 6, wherein the sulfuric acid tank 21 is connected with the resin tower 6 through a pickling pipe 24, and a control valve 27 and a delivery pump 28 are arranged on the pickling pipe 24; the sodium hydroxide tank 23 is connected with the resin tower 6 through an alkaline washing pipe 25, and a control valve 27 and a delivery pump 28 are arranged on the alkaline washing pipe 25; the desalting water tank 22 is connected with the resin tower 6 through a desalting water pipe 26, and a control valve 27 and a delivery pump 28 are arranged on the desalting water pipe 26;

bipolar membrane device cleaning system: the device comprises a sulfuric acid tank 21 and a desalination water tank 22 which are connected with a bipolar membrane device 7, wherein the sulfuric acid tank 21 is connected with the bipolar membrane device 7 through a pickling pipe 24, and a control valve 27 and a delivery pump 28 are arranged on the pickling pipe 24; the desalination water tank 22 is connected with the bipolar membrane device 7 through a desalination water pipe 26, and a control valve 27 and a delivery pump 28 are arranged on the desalination water pipe 26;

the nanofiltration device cleaning system comprises a return pipe 29 connected with the nanofiltration device 10, the other end of the return pipe 29 is connected with a filtrate tank, a control valve 27 and a delivery pump 28 are arranged on the return pipe 29, the filtrate tank is connected with a filtrate outlet of the nanofiltration device 10, and the filtrate tank is used for collecting filtrate in the nanofiltration device 10;

reverse osmosis unit cleaning system: the device comprises a desalination water tank 22 connected with a reverse osmosis device 9, wherein the desalination water tank 22 is connected with the reverse osmosis device 9 through a desalination water pipe 26, and a control valve 27 and a delivery pump 28 are arranged on the desalination water pipe 26;

Acid salt separation device cleaning system: comprises a salt removing water tank 22 connected with a salt separating device 11, the salt removing water tank 22 is connected with the salt separating device 11 through a salt removing water pipe 26, and a control valve 27 and a delivery pump 28 are arranged on the salt removing water pipe 26.

Example 2

Based on example 1, further:

the blending tank 3, the coarse filtering device 4, the fine filtering device 5, the resin tower 6, the bipolar membrane device 7, the nanofiltration device 10, the reverse osmosis device 9 and the acid salt separation device 11 are all connected with a sewage pipe 30, the sewage pipe 30 is connected with a collecting tank 31, and the sewage pipe 30 is provided with a delivery pump 28.

Example 3

Based on example 2, further:

the number of the resin towers 6 is 3, the resin towers 6 and the resin towers 6 are connected through a conveying pipe 16, a switching valve 17 and a zinc ion detector 18 are arranged on the conveying pipe 16, and the detection range of the zinc ion detector 18 is 0-3 ppm.

Example 4

On the basis of example 3, further:

the viscose waste liquid environment-friendly treatment system comprises a centrifugal machine 1, a transfer tank 2, a blending tank 3, a coarse filtering device 4, a fine filtering device 5, a resin tower 6, a circulating tank 8 and a bipolar membrane device 7, wherein the transfer tank 2 is arranged at one side of a station of the centrifugal machine 1; the transfer tank 2 is connected with a desalted water storage tank 12, and the transfer tank 2 is connected with the blending tank 3; the blending tank 3 is connected with a temperature-adjusting heat exchanger 14, a pH-adjusting alkali storage tank 15 and a sodium sulfate concentration-adjusting salt storage tank 13, and the blending tank 3 is connected with the coarse filtering device 4; the coarse filtering device 4 is connected with the fine filtering device 5, the fine filtering device 5 is connected with the resin tower 6, the resin tower 6 is connected with the bipolar membrane device 7 through the circulating tank 8, and an independent circulating passage is formed between the circulating tank 8 and the bipolar membrane device 7;

The acid outlet of the bipolar membrane device 7 is connected with a reverse osmosis device 9, the concentrated acid outlet of the reverse osmosis device 9 is directly connected with an acid station acid storage tank in the viscose fiber production process through an acid pipe, and the permeate outlet of the reverse osmosis device 9 is directly connected with the bipolar membrane device 7;

the alkali outlet of the bipolar membrane device 7 is connected with a nanofiltration device 10, the filtrate outlet of the nanofiltration device 10 is directly connected with a stock solution storage tank in the viscose fiber production process through an alkali pipe, and the concentrated solution outlet of the nanofiltration device 10 is directly connected with a blending tank 3 through a salt pipe;

the salt outlet of the bipolar membrane device 7 is connected with an acid salt separating device 11, the acid outlet of the acid salt separating device 11 is directly connected with an acid station acid storage tank in the viscose fiber production process through an acid pipe, and the salt outlet of the acid salt separating device 11 is directly connected with the transfer tank 2 through the salt pipe.

Example 5

On the basis of example 4, further:

the coarse filter device 4 is a bag filter with a pore diameter of 10 mu m, and the fine filter device 5 is an ultra-filter with a pore diameter of 0.01 mu m.

Example 6

On the basis of example 5, this example differs in that:

the coarse filter device 4 is a bag filter with a pore diameter of 15 mu m, and the fine filter device 5 is an ultra-filter with a pore diameter of 0.05 mu m.

Example 7

On the basis of examples 5-6, this example differs in that:

The coarse filter device 4 is a bag filter with a pore diameter of 13 μm, and the fine filter device 5 is an ultra-filter with a pore diameter of 0.02 μm.

Example 8

A. adopting a master controller 19 to carry out on-line detection on an environment-friendly viscose waste liquid treatment system, judging whether a cleaning system of a blending tank, a cleaning system of a coarse filtering device, a cleaning system of a fine filtering device, a cleaning system of a resin tower, a cleaning system of a bipolar membrane device, a cleaning system of a nanofiltration device, a cleaning system of a reverse osmosis device or a cleaning system of an acid salt separation device meets cleaning conditions, and then selecting a point to be cleaned;

B. the DCS controller 20 is connected to the blending tank cleaning system, the coarse filtration device cleaning system, the fine filtration device cleaning system, the resin tower cleaning system, the bipolar membrane device cleaning system, the nanofiltration device cleaning system, the reverse osmosis device cleaning system or the acid salt separation device cleaning system, and cleans the points to be cleaned by switching the control valve 27 and the transfer pump 28;

C. after the cleaning of the cleaning point is finished, the generated sewage is conveyed to a collecting tank 31 through a sewage pipe 30 for the next treatment.

Example 9

On the basis of example 8, the following description will be given of the case where the dispense tank 3 is cleaned by the dispense tank cleaning system.

The conditions in the compounding tank 3 that require cleaning include: the precipitation amount is 0.6-1 t;

the cleaning process comprises the following steps: circularly cleaning for 1h under the conditions that the temperature is 35 ℃ and the pH is 1.8; the method specifically comprises the following steps: firstly, sulfuric acid with the concentration of 8 percent is introduced into a blending tank 3 through a sulfuric acid tank 21 for 10m, and the mixture is subjected to the steps of cleaning, circulation and discharge; introducing desalted water 5m into the blending tank 3 through the desalted water tank 22, flushing and discharging;

after the cleaning is finished, the indexes in the blending tank 3 meet the following conditions: the precipitation amount was 0.008t;

the wastewater produced in the blending tank 3 included 8.1wt.% zinc sulfate.

Example 10

the cleaning process comprises the following steps: cleaning for 2h at 40 ℃ and pH of 1; the method specifically comprises the following steps: firstly, introducing sulfuric acid with the concentration of 8% into a blending tank 3 through a sulfuric acid tank 21 for 12m, cleaning, circulating and discharging; then the desalted water tank 22 is used for introducing 10m of desalted water into the blending tank 3, flushing and discharging;

after the cleaning is finished, the indexes in the blending tank 3 meet the following conditions: the precipitation amount is 0.005t;

The wastewater produced in the blending tank 3 included 13.5wt.% zinc sulfate and 3.3 wt wt.% sulfuric acid.

Example 11

the cleaning process comprises the following steps: cleaning for 1.5h at 37 ℃ and pH of 1.5; the method specifically comprises the following steps: firstly, sulfuric acid 11m with the concentration of 8% is introduced into a blending tank 3 through a sulfuric acid tank 21 for carrying out the steps of removing the solution, cleaning, circulating and discharging; introducing desalted water 8m into the blending tank 3 through the desalted water tank 22, flushing and discharging;

the wastewater produced in the blending tank 3 included 10.21wt.% zinc sulfate and 2.4 wt wt.% sulfuric acid.

Example 12

On the basis of example 8, the following description will be given of the case where the coarse filtration device 4 is cleaned by using the coarse filtration device cleaning system.

Conditions under which the coarse filtration device 4 needs to be cleaned include: the filtering pressure is more than 0.5MPa;

the cleaning process comprises the following steps: washing for 1h at 30 ℃ and pH of 1.5; the method specifically comprises the following steps: firstly, sulfuric acid with the concentration of 6 percent is introduced into a coarse filtering device 4 through a sulfuric acid tank 21 for 1m solution, cleaned and discharged; then introducing desalted water 2m into the coarse filter device 4 through a desalted water tank 22, cleaning and discharging;

After the cleaning is finished, the indexes in the coarse filter device 4 meet the following conditions: zinc ion 9ppm;

the sewage produced by the coarse filtration device 4 comprises 80 wt percent of zinc sulfate.

Example 13

the cleaning process comprises the following steps: washing for 2h at 40 ℃ and pH of 1.1; the method specifically comprises the following steps: firstly, sulfuric acid 2m with the concentration of 8% is introduced into a coarse filtering device 4 through a sulfuric acid tank 21, washed and discharged; introducing desalted water 3m into the coarse filter device 4 through the desalted water tank 22, cleaning and discharging;

after the cleaning is finished, the indexes in the coarse filter device 4 meet the following conditions: zinc ion 5ppm;

Example 14

the cleaning process comprises the following steps: cleaning for 1.5h at 35 ℃ and pH of 1.9; the method specifically comprises the following steps: firstly, sulfuric acid with the concentration of 7 percent is introduced into a coarse filtering device 4 through a sulfuric acid tank 21 for 1.5m for a long period of time, and is cleaned and discharged; introducing desalted water 2.5m into the coarse filter device 4 through the desalted water tank 22, cleaning and discharging;

After the cleaning is finished, the indexes in the coarse filter device 4 meet the following conditions: zinc ion of 6ppm;

the sewage produced by the coarse filtration device 4 comprises 70 wt percent of zinc sulfate.

Example 15

On the basis of example 8, the cleaning of the fine filter 5 by the fine filter cleaning system will be described.

Conditions under which the fine filter device 5 needs to be cleaned include: the filtrate flux decreased by 30%;

the cleaning process comprises the following steps: cleaning for 0.5h at 40 ℃ and pH of 1.7; the method specifically comprises the following steps: firstly, sulfuric acid with the concentration of 0.5 percent is introduced into the fine filtering device 5 through the sulfuric acid tank 21 for 5m solution, and the solution is cleaned, circulated and discharged; then the desalted water is introduced into the fine filtering device 5 through the desalted water tank 22 for 1m for filtration, and the filtered water is cleaned and discharged;

after the cleaning is finished, indexes in the fine filtering device 5 meet the following conditions: the filtrate flux was 99.67%;

the contaminated water produced by the fine filtration apparatus 5 included 0.5wt.% zinc sulfate.

Example 16

the cleaning process comprises the following steps: cleaning for 1h at 50 ℃ and pH of 1; the method specifically comprises the following steps: firstly, sulfuric acid with the concentration of 0.5 percent is introduced into the fine filtering device 5 through a sulfuric acid tank 21 for 10m for cleaning, circulating and discharging; then the desalted water tank 22 is used for introducing desalted water 2m into the fine filtering device 5 for filtration, cleaning and discharging;

After the cleaning is finished, indexes in the fine filtering device 5 meet the following conditions: the filtrate flux was 98.99%;

Example 17

the cleaning process comprises the following steps: cleaning for 0.8h at 45 ℃ and pH of 1.3; the method specifically comprises the following steps: firstly, sulfuric acid with the concentration of 0.5 percent is introduced into the fine filtering device 5 through the sulfuric acid tank 21 for 7m for cleaning, circulating and discharging; then the desalted water 1.5m is introduced into the fine filtering device 5 through the desalted water tank 22, cleaned and discharged;

after the cleaning is finished, indexes in the fine filtering device 5 meet the following conditions: the filtrate flux was 99%;

Example 18

On the basis of example 8, the resin column 6 was cleaned by a resin column cleaning system.

The conditions under which the resin column 6 is cleaned include: zinc ions in the liquid are more than 1ppm;

the cleaning process comprises the following steps: cleaning for 25 hours under normal temperature; the method specifically comprises the following steps: firstly, introducing desalted water into the resin tower 6 through a desalted water tank 22 for 60m for washing and discharging; then, sulfuric acid with the concentration of 8% is introduced into the resin tower 6 through a sulfuric acid tank 21 for 20m, and the resin tower is cleaned, circulated and discharged; thirdly, introducing desalted water 40m into the resin tower 6 through the desalted water tank 22, washing to be neutral, and discharging; finally, introducing sodium hydroxide 7m with the concentration of 8% into the resin tower 6 through a sodium hydroxide tank 23, circularly discharging, and keeping the pH value of the internal environment of the resin tower 6 at 8;

After the cleaning is finished, indexes in the resin tower 6 meet the following conditions: zinc ion in the liquid is 0.7ppm;

the effluent produced by the resin column 6 included 0.08wt.% zinc sulfate and 7wt.% sulfuric acid.

Example 19

the cleaning process comprises the following steps: cleaning for 30 hours under normal temperature; the method specifically comprises the following steps: firstly, introducing desalted water into the resin tower 6 through a desalted water tank 22 for 80m, flushing and discharging; then, sulfuric acid 30m with the concentration of 8% is introduced into the resin tower 6 through a sulfuric acid tank 21 for cleaning, circulation and discharge; thirdly, introducing desalted water into the resin tower 6 through the desalted water tank 22 for 50m for a period of time, flushing to neutrality, and discharging; finally, 10m sodium hydroxide with the concentration of 8% is introduced into the resin tower 6 through a sodium hydroxide tank 23, circulated and discharged, and the pH value of the internal environment of the resin tower 6 is kept at 9;

after the cleaning is finished, indexes in the resin tower 6 meet the following conditions: zinc ions in the liquid are 0.4ppm;

Example 20

the cleaning process comprises the following steps: cleaning for 27h under normal temperature; the method specifically comprises the following steps: firstly, introducing desalted water into the resin tower 6 through a desalted water tank 22 for 70m, flushing and discharging; secondly, sulfuric acid 25m with the concentration of 8 percent is introduced into the resin tower 6 through a sulfuric acid tank 21 for cleaning, circulation and discharge; thirdly, introducing desalted water 45m into the resin tower 6 through the desalted water tank 22, flushing to neutrality, and discharging; finally, 8.5m sodium hydroxide with the concentration of 8 percent is introduced into the resin tower 6 through a sodium hydroxide tank 23 for a long period of time, circulated and discharged, and the pH value of the internal environment of the resin tower 6 is kept at 8.5;

after the cleaning is finished, indexes in the resin tower 6 meet the following conditions: zinc ion in the liquid is 0.9ppm;

Example 21

On the basis of example 8, the bipolar membrane device 7 was cleaned by using a bipolar membrane device cleaning system.

Conditions under which bipolar membrane device 7 requires cleaning include: the voltage of the membrane stack mechanism is more than 270V;

the cleaning process comprises the following steps: washing for 5h at 30 ℃ under the conditions of pH of 1.8 and pressure of 0.05 Mpa; the method specifically comprises the following steps: firstly, introducing desalted water 8m into the bipolar membrane device 7 through a desalted water tank 22, washing and discharging; then, sulfuric acid with the concentration of 0.5 percent is introduced into the bipolar membrane device 7 through a sulfuric acid tank 21 for 8m solution, and the solution is circulated, soaked, cleaned and discharged; finally, introducing desalted water 8m into the bipolar membrane device 7 through the desalted water tank 22, flushing and discharging;

After the cleaning is finished, indexes in the bipolar membrane device 7 meet the following conditions: the voltage of the membrane stack mechanism is 240V;

the wastewater produced by the bipolar membrane device 7 included 0.01wt.% zinc sulfate and 0.4wt.% sulfuric acid.

Example 22

the cleaning process comprises the following steps: washing for 6h at 35 ℃ under the conditions of pH of 1.5 and pressure of 0.05 Mpa; the method specifically comprises the following steps: firstly, introducing desalted water into the bipolar membrane device 7 through a desalted water tank 22 for 10m, flushing and discharging; then sulfuric acid with the concentration of 2 percent is introduced into the bipolar membrane device 7 through a sulfuric acid tank 21 for 10m solution, circulated, soaked, cleaned and discharged; finally, introducing desalted water 10m into the bipolar membrane device 7 through the desalted water tank 22, flushing and discharging;

after the cleaning is finished, indexes in the bipolar membrane device 7 meet the following conditions: the voltage of the membrane stack mechanism is 260V;

the wastewater produced by the bipolar membrane device 7 included 0.01wt.% zinc sulfate and 0.9wt.% sulfuric acid.

Example 23

the cleaning process comprises the following steps: cleaning for 5.5h at 33 ℃ under the conditions of pH of 1.0 and pressure of 0.05 Mpa; the method specifically comprises the following steps: firstly, introducing desalted water 9m into the bipolar membrane device 7 through a desalted water tank 22, washing and discharging; then, sulfuric acid with the concentration of 1.4 percent is introduced into the bipolar membrane device 7 through a sulfuric acid tank 21 for 9m solution, and the solution is circulated, soaked, cleaned and discharged; finally, introducing desalted water 9m into the bipolar membrane device 7 through the desalted water tank 22, flushing and discharging;

after the cleaning is finished, indexes in the bipolar membrane device 7 meet the following conditions: the voltage of the membrane stack mechanism is 250V;

the wastewater produced by the bipolar membrane device 7 included 0.01wt.% zinc sulfate and 0.6wt.% sulfuric acid.

Example 24

On the basis of example 8, the nanofiltration device 10 was cleaned by using a nanofiltration device cleaning system.

Conditions under which the nanofiltration device 10 needs to be cleaned include: the flux of the nanofiltration membrane is reduced by 30%;

the cleaning process comprises the following steps: at normal temperature, 5m of filtrate in a filtrate outlet of the nanofiltration device 10 is conveyed back to the nanofiltration device 10 through a return pipe 29, and is cleaned for 0.5h;

after the cleaning is finished, indexes in the nanofiltration device 10 meet the following conditions: the flux of the nanofiltration membrane is 99.99 percent;

The wastewater produced by the nanofiltration device 10 included 0.2wt.% sodium sulfate and 4.5wt.% sodium hydroxide.

Example 25

the cleaning process comprises the following steps: at normal temperature, the filtrate 10m in the filtrate outlet of the nanofiltration device 10 is conveyed back to the nanofiltration device 10 through a return pipe 29, and is cleaned for 1h;

after the cleaning is finished, indexes in the nanofiltration device 10 meet the following conditions: the flux of the nanofiltration membrane is 99.7%;

the wastewater produced by the nanofiltration device 10 included 0.2wt.% sodium sulfate and 8wt.% sodium hydroxide.

Example 26

the cleaning process comprises the following steps: at normal temperature, the filtrate 8m in the filtrate outlet of the nanofiltration device is conveyed back to the nanofiltration device 10 through a return pipe 29, and is cleaned for 0.7h;

after the cleaning is finished, indexes in the nanofiltration device 10 meet the following conditions: the flux of the nanofiltration membrane is 98%;

the wastewater produced by the nanofiltration device 10 included 0.2wt.% sodium sulfate and 6wt.% sodium hydroxide.

Example 27

On the basis of example 8, the reverse osmosis unit 9 was cleaned by using a reverse osmosis unit cleaning system.

Conditions under which the reverse osmosis unit 9 needs to be purged include: the reverse osmosis flux is reduced by 30%;

the cleaning process comprises the following steps: introducing desalted water 15m into the reverse osmosis device 9 through a desalted water tank 22 under the conditions of normal temperature and pressure of 3Mpa, and cleaning for 0.5h;

after the cleaning is finished, indexes in the reverse osmosis device 9 meet the following conditions: reverse osmosis flux was 100%;

the sewage produced by the reverse osmosis unit 9 includes 0.1wt.% sulfuric acid.

Example 28

the cleaning process comprises the following steps: introducing desalted water 20m into the reverse osmosis device 9 through a desalted water tank 22 under the conditions of normal temperature and pressure of 3Mpa, and cleaning for 1h;

after the cleaning is finished, indexes in the reverse osmosis device 9 meet the following conditions: reverse osmosis flux was 98.6%;

Example 29

the cleaning process comprises the following steps: introducing desalted water 17m into the reverse osmosis device 9 through a desalted water tank 22 under the conditions of normal temperature and pressure of 3Mpa, and cleaning for 0.8h;

after the cleaning is finished, indexes in the reverse osmosis device 9 meet the following conditions: the reverse osmosis flux is 99%;

Example 30

On the basis of example 8, the cleaning of the acid salt separator 11 by the acid salt separator cleaning system was described as an example.

The conditions under which the acid salt separation means 11 needs to be cleaned include: the acid content in the salt solution is more than 1g/L;

the cleaning process comprises the following steps: introducing desalted water into the acid salt separating device 11 through the desalted water tank 22 for 15m for cleaning for 0.5h at normal temperature;

after the cleaning, the indexes in the acid salt separating device 11 satisfy the following conditions: the acid content in the salt solution is 0.04g/L;

the sewage produced by the acid salt separation means 11 contained 5g/L sulfuric acid.

Example 31

The cleaning process comprises the following steps: introducing desalted water into the acid salt separating device 11 through a desalted water tank 22 for 20m for cleaning for 1h under the normal temperature condition;

after the cleaning, the indexes in the acid salt separating device 11 satisfy the following conditions: the acid content in the salt solution is 0.05g/L;

the sewage produced by the acid salt separation means 11 includes 15g/L sulfuric acid.

Example 32

the cleaning process comprises the following steps: introducing desalted water 18m into the acid salt separating device 11 through a desalted water tank 22 at normal temperature, and cleaning for 0.7h;

after the cleaning, the indexes in the acid salt separating device 11 satisfy the following conditions: the acid content in the salt solution is 0.09g/L;

the waste water produced by the acid salt separation means 11 contains 10g/L sulfuric acid.

Claims

1. An online cleaning system of an environment-friendly viscose waste liquid treatment system is characterized by comprising a centrifugal machine (1), a transfer tank (2), a blending tank (3), a coarse filtering device (4), a fine filtering device (5), a resin tower (6), a circulating tank (8) and a bipolar membrane device (7), wherein the transfer tank (2) is arranged at one side of a station of the centrifugal machine (1); the transfer tank (2) is connected with a desalted water storage tank (12), and the transfer tank (2) is connected with the blending tank (3); the blending tank (3) is connected with a temperature-adjusting heat exchanger (14), a pH-adjusting alkali storage tank (15) and a sodium sulfate concentration-adjusting salt storage water tank (13), and the blending tank (3) is connected with the coarse filtering device (4); the coarse filtering device (4) is connected with the fine filtering device (5), the fine filtering device (5) is connected with the resin tower (6), the resin tower (6) is connected with the bipolar membrane device (7) through the circulating tank (8), and an independent circulating passage is formed between the circulating tank (8) and the bipolar membrane device (7);

The acid outlet of the bipolar membrane device (7) is connected with a reverse osmosis device (9), the concentrated acid outlet of the reverse osmosis device (9) is directly connected with an acid station acid storage tank in the viscose fiber production process through an acid pipe, and the permeate outlet of the reverse osmosis device (9) is directly connected with the bipolar membrane device (7);

the alkali outlet of the bipolar membrane device (7) is connected with a nanofiltration device (10), the filtrate outlet of the nanofiltration device (10) is directly connected with a stock solution storage tank in the viscose fiber production process through an alkali pipe, and the concentrate outlet of the nanofiltration device (10) is directly connected with a blending tank (3) through a salt pipe;

the salt outlet of the bipolar membrane device (7) is connected with an acid salt separating device (11), the acid outlet of the acid salt separating device (11) is directly connected with an acid station acid storage tank in the viscose fiber production process through an acid pipe, and the salt outlet of the acid salt separating device (11) is directly connected with a transfer tank (2) through a salt pipe;

the online cleaning system of the viscose waste liquid environment-friendly treatment system comprises: the system comprises a main controller (19) for performing on-line detection, a DCS controller (20) connected with the main controller (19), and a blending tank cleaning system, a coarse filter device cleaning system, a fine filter device cleaning system, a resin tower cleaning system, a bipolar membrane device cleaning system, a nanofiltration device cleaning system, a reverse osmosis device cleaning system and an acid salt separation device cleaning system which are all connected with the DCS controller (20);

The blending tank cleaning system comprises a sulfuric acid tank (21) and a desalination water tank (22) which are connected with the blending tank (3), wherein the sulfuric acid tank (21) is connected with the blending tank (3) through a pickling pipe (24), and a control valve (27) and a conveying pump (28) are arranged on the pickling pipe (24); the desalination water tank (22) is connected with the blending tank (3) through a desalination water pipe (26), and a control valve (27) and a delivery pump (28) are arranged on the desalination water pipe (26);

the cleaning system of the coarse filtration device comprises a sulfuric acid tank (21) and a desalination water tank (22) which are connected with the coarse filtration device (4), wherein the sulfuric acid tank (21) is connected with the coarse filtration device (4) through an acid washing pipe (24), and the acid pipe is provided with a control valve (27) and a delivery pump (28); the desalting water tank (22) is connected with the coarse filtering device (4) through a desalting water pipe (26), and a control valve (27) and a delivery pump (28) are arranged on the desalting water pipe (26);

the cleaning system of the fine filtering device comprises a sulfuric acid tank (21) and a desalination water tank (22) which are connected with the fine filtering device (5), the sulfuric acid tank (21) is connected with the fine filtering device (5) through a pickling pipe (24), and a control valve (27) and a delivery pump (28) are arranged on the pickling pipe (24); the desalting water tank (22) is connected with the fine filtering device (5) through a desalting water pipe (26), and a control valve (27) and a delivery pump (28) are arranged on the desalting water pipe (26);

The resin tower cleaning system comprises a sulfuric acid tank (21), a sodium hydroxide tank (23) and a desalination water tank (22), which are connected with a resin tower (6), wherein the sulfuric acid tank (21) is connected with the resin tower (6) through a pickling pipe (24), and a control valve (27) and a conveying pump (28) are arranged on the pickling pipe (24); the sodium hydroxide tank (23) is connected with the resin tower (6) through an alkaline washing pipe (25), and a control valve (27) and a delivery pump (28) are arranged on the alkaline washing pipe (25); the desalting water tank (22) is connected with the resin tower (6) through a desalting water pipe (26), and a control valve (27) and a delivery pump (28) are arranged on the desalting water pipe (26);

the bipolar membrane device cleaning system comprises a sulfuric acid tank (21) and a desalination water tank (22) which are connected with a bipolar membrane device (7), wherein the sulfuric acid tank (21) is connected with the bipolar membrane device (7) through a pickling pipe (24), and a control valve (27) and a delivery pump (28) are arranged on the pickling pipe (24); the desalination water tank (22) is connected with the bipolar membrane device (7) through a desalination water pipe (26), and a control valve (27) and a delivery pump (28) are arranged on the desalination water pipe (26);

the nanofiltration device cleaning system comprises a return pipe (29) connected with the nanofiltration device (10), the other end of the return pipe (29) is connected with a filtrate tank, and a control valve (27) and a delivery pump (28) are arranged on the return pipe (29);

The reverse osmosis device cleaning system comprises a desalination water tank (22) connected with a reverse osmosis device (9), the desalination water tank (22) is connected with the reverse osmosis device (9) through a desalination water pipe (26), and a control valve (27) and a delivery pump (28) are arranged on the desalination water pipe (26);

the cleaning system of the acid salt separating device comprises a salt removing water tank (22) connected with the acid salt separating device (11), the salt removing water tank (22) is connected with the acid salt separating device (11) through a salt removing water pipe (26), and a control valve (27) and a conveying pump (28) are arranged on the salt removing water pipe (26);

the system comprises a blending tank (3), a coarse filtering device (4), a fine filtering device (5), a resin tower (6), a bipolar membrane device (7), a nanofiltration device (10), a reverse osmosis device (9) and an acid salt separation device (11), wherein the blending tank is connected with a sewage pipe (30), the sewage pipe (30) is connected with a collecting tank (31), and a conveying pump (28) is arranged on the sewage pipe (30);

at least 3 resin towers (6), the resin towers (6) are connected with the resin towers (6) through conveying pipes (16), a switching valve (17) and a zinc ion detector (18) are arranged on the conveying pipes (16), and the detection range of the zinc ion detector (18) is 0-3 ppm.

2. The online cleaning system of the viscose waste liquid environment-friendly treatment system according to claim 1, wherein the coarse filtering device (4) is a bag filter with the aperture of 10-15 μm, and the fine filtering device (5) is an ultra-filter with the aperture of 0.01-0.05 μm.

3. The cleaning method of an online cleaning system of an environmental protection treatment system for viscose waste liquid according to claim 1, comprising the steps of:

A. adopting a master controller (19) to carry out on-line detection on the viscose waste liquid environment-friendly treatment system, judging whether a blending tank cleaning system, a coarse filter device cleaning system, a fine filter device cleaning system, a resin tower cleaning system, a bipolar membrane device cleaning system, a nanofiltration device cleaning system, a reverse osmosis device cleaning system or an acid salt separation device cleaning system meet cleaning conditions, and then selecting points to be cleaned;

B. the DCS controller (20) is communicated with the blending tank cleaning system, the coarse filter device cleaning system, the fine filter device cleaning system, the resin tower cleaning system, the bipolar membrane device cleaning system, the nanofiltration device cleaning system, the reverse osmosis device cleaning system or the acid salt separation device cleaning system, and the point to be cleaned is cleaned through switching of the control valve (27) and the conveying pump (28);

C. After the cleaning of the cleaning point is finished, the generated sewage is conveyed to a collecting tank (31) through a sewage pipe (30) for the next treatment.

4. The method for cleaning an online cleaning system of an environmental protection treatment system for viscose waste liquid according to claim 3, wherein in step A,

the conditions under which the blending tank (3) needs to be cleaned include: the precipitation amount is 0.6-1 t;

the conditions under which the coarse filtration device (4) needs to be cleaned include: the filtering pressure is more than 0.5MPa;

the conditions under which the fine filtration device (5) needs to be cleaned include: the filtrate flux decreased by 30%;

the conditions under which the resin tower (6) is cleaned include: zinc ions in the liquid are more than 1ppm;

the conditions under which the bipolar membrane device (7) needs to be cleaned include: the voltage of the membrane stack mechanism is more than 270V;

the conditions under which the nanofiltration device (10) needs to be cleaned include: the flux of the nanofiltration membrane is reduced by 30%;

the conditions under which the reverse osmosis device (9) needs to be cleaned include: the reverse osmosis flux is reduced by 30 percent

The conditions under which the acid salt separation device (11) needs to be cleaned include: the acid content in the salt solution is more than 1g/L.

5. The method for cleaning an online cleaning system of a viscose waste liquid environmental protection treatment system according to claim 3 or 4, wherein, in the step B,

When the blending tank (3) is cleaned, the cleaning is carried out for 1 to 2 hours under the conditions that the temperature is 35 to 40 ℃ and the pH is less than 2; the method specifically comprises the following steps: firstly, sulfuric acid with the concentration of 8 percent is introduced into a blending tank (3) through a sulfuric acid tank (21) for 10-12 m, and then desalted water is introduced into the blending tank (3) through a desalted water tank (22) for 5-10 m;

when the coarse filter device (4) is cleaned, the coarse filter device is cleaned for 1 to 2 hours under the conditions that the temperature is 30 to 40 ℃ and the pH is less than 2; the method specifically comprises the following steps: firstly, sulfuric acid with the concentration of 6-8% is introduced into a coarse filtration device (4) through a sulfuric acid tank (21), and then desalted water with the concentration of 2-3 m is introduced into the coarse filtration device (4) through a desalted water tank (22);

when the fine filtering device (5) is cleaned, the cleaning is carried out for 0.5 to 1 hour under the conditions that the temperature is 40 to 50 ℃ and the pH is less than 2; the method specifically comprises the following steps: firstly, sulfuric acid with the concentration of 0.5 percent is introduced into a fine filtering device (5) through a sulfuric acid tank (21), and then desalted water with the concentration of 1-2 m is introduced into the fine filtering device (5) through a desalted water tank (22);

when the resin tower (6) is cleaned, cleaning is carried out for 25-30 h under the normal temperature condition; the method specifically comprises the following steps: firstly, introducing 60-80 m of desalted water into a resin tower (6) through a desalted water tank (22), secondly, introducing 20-30 m of sulfuric acid with the concentration of 8% into the resin tower (6) through a sulfuric acid tank (21), thirdly, introducing 40-50 m of desalted water into the resin tower (6) through the desalted water tank (22), and finally, introducing 7-10 m of sodium hydroxide with the concentration of 8% into the resin tower (6) through a sodium hydroxide tank (23), wherein the pH value of the internal environment of the resin tower (6) is kept to be 8-9;

When the bipolar membrane device (7) is cleaned, the bipolar membrane device is cleaned for 5 to 6 hours under the conditions that the temperature is 30 to 35 ℃, the pH is less than 2 and the pressure is 0.05 Mpa; the method specifically comprises the following steps: firstly, introducing desalted water 8-10 m into a bipolar membrane device (7) through a desalted water tank (22), then introducing sulfuric acid with the concentration of 0.5-2% into the bipolar membrane device (7) through a sulfuric acid tank (21), and finally, introducing desalted water 8-10 m into the bipolar membrane device (7) through the desalted water tank (22);

when the nanofiltration device (10) is cleaned, 5-10 m of filtrate in a filtrate outlet of the nanofiltration device (10) is conveyed back to the nanofiltration device (10) through a return pipe (29) under the normal temperature condition, and the cleaning is carried out for 0.5-1 h;

when the reverse osmosis device (9) is cleaned, desalted water is introduced into the reverse osmosis device (9) through a desalted water tank (22) for 15-20 m under the conditions of normal temperature and pressure of 3Mpa, and the reverse osmosis device is cleaned for 0.5-1 h;

when the acid salt separation device (11) is cleaned, desalted water is introduced into the acid salt separation device (11) for 15-20 m in a low temperature through a desalted water tank (22), and the cleaning is carried out for 0.5-1 h.

6. The method for cleaning an online cleaning system of an environmental protection treatment system for viscose waste liquid according to claim 3, wherein in the step C, after the cleaning is finished, the following criteria are satisfied:

The precipitation amount in the blending tank (3) is less than 0.01t;

the zinc ions in the coarse filtering device (4) are less than 10ppm;

the filtrate flux of the fine filtering device (5) is more than 98 percent;

zinc ions in the liquid discharged from the resin tower (6) are less than 1ppm;

the voltage of a membrane stack mechanism in the bipolar membrane device (7) is 200-270V;

the flux of the nanofiltration membrane in the nanofiltration device (10) is more than 98 percent;

the reverse osmosis flux in the reverse osmosis device (9) is more than 98 percent;

the acid content of the salt solution in the acid salt separation device (11) is lower than 0.1g/L.

7. The method for cleaning an online cleaning system of an environmental protection treatment system for viscose waste liquid according to claim 3, wherein, in the step C, after the cleaning is finished,

the sewage generated by the blending tank (3) comprises 8.1 to 13.5 weight percent of zinc sulfate and 0 to 3.3 and wt weight percent of sulfuric acid;

the sewage generated by the coarse filtering device (4) comprises 60 to 80 weight percent of zinc sulfate;

the sewage generated by the fine filtering device (5) comprises 0.5wt.% zinc sulfate;

the sewage produced by the resin tower (6) comprises 0.08wt.% zinc sulfate and 7 wt wt.% sulfuric acid;

the sewage generated by the bipolar membrane device (7) comprises 0.01wt.% zinc sulfate and 0.4-0.9 wt.% sulfuric acid;

The sewage generated by the nanofiltration device (10) comprises 0.2wt.% of sodium sulfate and 4.5-8 wt.% of sodium hydroxide;

the sewage produced by the reverse osmosis device (9) comprises 0.1wt.% sulfuric acid;

the sewage generated by the acid salt separation device (11) comprises 5-15 g/L sulfuric acid.