CN212151923U

CN212151923U - Circulating cooling water desalting treatment system based on frequent reverse electrode electrodialysis

Info

Publication number: CN212151923U
Application number: CN201922284763.4U
Authority: CN
Inventors: 施小林; 肖彬彬
Original assignee: Hangzhou Jiangrongdao Environmental Technology Co ltd
Current assignee: Hangzhou Jiangrongdao Environmental Technology Co ltd
Priority date: 2019-12-18
Filing date: 2019-12-18
Publication date: 2020-12-15
Anticipated expiration: 2029-12-18

Abstract

The utility model discloses a desalination treatment system of recirculated cooling water based on frequent reversal electrode electrodialysis, including preliminary treatment mechanism, preliminary treatment mechanism is including the clarification device in advance, multi-media filter equipment and the adsorption equipment who connects gradually, adsorption equipment connects the concentrated mechanism of frequent reversal electrode electrodialysis, and the waste liquid that filters out by adsorption equipment gets into the concentrated mechanism of desalination and carries out the desalination concentration, the desalination liquid pool of the concentrated mechanism of frequent reversal electrode electrodialysis is connected to the fresh water pond, the concentrated liquid pool of the concentrated mechanism of frequent reversal electrode electrodialysis is connected to the dense water pond, and the dense water outlet of dense water pond is connected to the crystallization mechanism, carries out evaporative crystallization salt manufacturing or flue spraying with dense water, and the rate of recovery of fresh water is about 90%, and the dense water yield of production is about 10%, and the concentration multiplying power of dense water is about 7-8 times; thereby realizing the concentration and reduction of pollutants and recycling water resources.

Description

Circulating cooling water desalting treatment system based on frequent reverse electrode electrodialysis

Technical Field

The utility model belongs to the technical field of the environmental protection water treatment, concretely relates to circulative cooling water's desalination system based on cement trade of frequent electrode switching electrodialysis.

Background

The water used by cement manufacturing enterprises mainly comprises process water and domestic water, the process water is mainly used for equipment cooling, and most of the process water except loss due to evaporation, leakage and the like is recycled and utilized. The production and living wastewater is recycled in a production water system after advanced treatment, and becomes a great trend of enterprises for improving benefits, cleaning production, saving energy, reducing consumption and reducing environmental pollution. In the process of a circulating cooling system, along with the continuous evaporation and concentration of cooling water, the concentration multiple is gradually increased, the ion concentration in water is also multiplied, organic substances and salt ions, including suspended solids and various ionic salts, are continuously accumulated in a circulating water pipeline, so that the phenomena of equipment corrosion, microorganism breeding, pipeline blockage, corrosion and scaling are easily caused, and the adding of a medicament becomes a common effective method. However, with the increase of environmental protection, many enterprises want to prevent the water in the whole circulating cooling system from being discharged outside and realize zero pollution discharge, which means that the cooling water in the system is infinitely concentrated, the concentration of various ions is greatly increased, and the tendency of equipment scaling, corrosion and bacterial and algae breeding is more serious. Therefore, a comprehensive water treatment scheme of the system is urgently needed to solve the problems, a circulating cooling water system needs to be considered in a whole set, optimized and improved, the concentration ratio is improved as much as possible, the discharge of circulating cooling water is reduced, meanwhile, the desalting and recycling of sewage are effectively completed, and the phenomena of scaling and serious corrosion due to the overhigh concentration ratio are considered, so that stricter requirements are provided for a circulating cooling water treatment technology. Therefore, a complete treatment scheme for the circulating cooling water is required to be searched so as to effectively solve the problem of corrosion and scaling of equipment under high times of a circulating cooling system.

The main water saving approach of the recirculating cooling system includes two aspects: (1) the concentration rate is improved, and the discharge capacity is reduced; (2) recycling the circulating water to discharge sewage. Although the concentration ratio of some circulating cooling water reaches 5-6, when the concentration ratio needs to be further improved, the water-saving benefit is small; the recycling of the circulating water and sewage becomes a new development trend, and some engineering examples exist in China. The main idea of recycling the sewage discharged by the circulating cooling water is to remove the salt continuously increased in the circulating cooling water system by adopting a bypass flow treatment process, and recycle the regenerated sewage as the make-up water to the circulating cooling water system, so that the recycling rate of the industrial water can be further improved, the discharge amount of the wastewater is reduced, the zero emission of the system is basically realized, and the effects of saving water, saving energy, reducing the production cost and the like are realized for a cement plant. The most common desalination processes at present comprise a biological method, an ion exchange method, a reverse osmosis method, an electrodialysis method and the like, wherein the reverse osmosis method and the electrodialysis method are most widely and mature in desalination;

the main defects of the reverse osmosis technology in the existing cement plant circulating cooling water desalination treatment are that a complex softening pretreatment unit is needed for removing calcium and magnesium hardness, a large amount of chemical agents such as lime, sodium carbonate and sodium hydroxide are added, inorganic precipitated sludge needs to be disposed, a large amount of agents such as scale inhibitors and bactericides need to be used when a reverse osmosis system operates, the operation cost is increased due to the use of a large amount of agents, a large amount of concentrated water fields generated by reverse osmosis cannot be automatically digested, if an evaporation crystallization process is arranged at the rear end of reverse osmosis, a large amount of concentrated water accounting for 40-50% of the total water inflow generated by reverse osmosis is treated, the salt content of the concentrated water is not high and is only 2-4 times that of raw water, the scale of an evaporation crystallizer is also greatly increased, the investment cost and the operation cost are further increased, and the reverse osmosis system and the evaporation, the operation is also rather cumbersome.

Secondly, the main disadvantage of the traditional electrodialysis technology (ED) in the existing cement plant circulating cooling water desalination treatment is that a softening pretreatment unit is also needed to remove calcium and magnesium hardness so as to avoid the problem of scale formation of electrodialysis concentrated solution, the softening pretreatment process flow is long, the operation requirement dosage is large, and the cost of investment and operation is increased because inorganic precipitated sludge is also generated and needs to be treated.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a recirculated cooling water's desalination processing system based on frequent electrode electrodialysis to solve the problem that exists in the recirculated cooling water desalination of cement plant that provides among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

the desalting treatment system of the circulating cooling water based on the frequent reverse electrode electrodialysis comprises a pretreatment mechanism, wherein the pretreatment mechanism comprises a pre-clarifying device, a multi-media filtering device and an adsorption device which are sequentially connected, the adsorption device is connected with the frequent reverse electrode electrodialysis concentration mechanism, waste liquid filtered by the adsorption device enters the desalting concentration mechanism to be desalted and concentrated, a desalted liquid tank of the frequent reverse electrode electrodialysis concentration mechanism is connected to a fresh water tank, a concentrated liquid tank of the frequent reverse electrode electrodialysis concentration mechanism is connected to a concentrated water tank, a concentrated water outlet of the concentrated water tank is connected to a crystallization mechanism, and concentrated water is evaporated, crystallized, salt making or flue spraying is carried out.

Preferably, the turbidity of the raw water treated by the pretreatment mechanism is less than 1 NTU.

Preferably, the adsorption device is an activated carbon adsorption device.

Compared with the prior art, the beneficial effects of the utility model are that:

on the premise of not obviously increasing the investment cost, the combined treatment device combining medium filtration, activated carbon adsorption and frequent reverse electrodialysis and crystallization salt making or flue spraying is adopted, so that the purposes of softening the pretreated circulating cooling water without adding medicaments, obviously reducing the medicament adding cost, shortening the process flow of a circulating cooling water treatment system, not generating inorganic precipitated sludge and effectively avoiding the problem of scaling at the concentrated solution side of an electrodialysis unit can be realized, a large amount of additional softening medicaments such as lime, sodium hydroxide, sodium carbonate and the like are not required to be added into the whole system, zero emission can be obviously reduced, the frequent reverse electrodialysis technology is adopted to treat the circulating cooling water of a cement plant, the recovery rate of fresh water is about 90%, the generated concentrated water amount is about 10%, and the concentration rate of the concentrated water is about 7-8 times; thereby realizing the concentration and reduction of pollutants and recycling water resources.

Drawings

Fig. 1 is a schematic view of the frame structure of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Circulating cooling water's desalination processing system based on frequent reverse electrode electrodialysis, including pretreatment mechanism, the raw water turbidity that handles through pretreatment mechanism is less than 1NTU, pretreatment mechanism is including the preceding clarification device 1, multimedium filter equipment 2 and the adsorption equipment 3 that connect gradually, the adsorption equipment is active carbon adsorption device, adsorption equipment connects frequent reverse electrode electrodialysis concentration mechanism 4, and the waste liquid that filters out by adsorption equipment gets into the concentrated mechanism of desalination and carries out the desalination and concentrate, the desalination liquid pool of the concentrated mechanism of frequent reverse electrode electrodialysis is connected to fresh water pool 5, the concentrated liquid pool of the concentrated mechanism of frequent reverse electrode electrodialysis is connected to concentrated pond 6, and the dense water exit linkage of concentrated pond is to crystallization mechanism 7, carries out evaporation crystallization salt manufacturing or flue spraying with dense water.

The utility model discloses a theory of operation:

simply pre-clarifying circulating cooling water entering an electrodialysis reversal (EDR) concentration unit, filtering by multiple media and pre-treating by activated carbon adsorption to remove large granular substances and organic matters such as suspended matters, colloids and the like and ensure that the turbidity of raw water entering the electrodialysis is less than 1 NTU; the interior of the frequent reverse Electrodialysis (EDR) membrane stack is provided with an anion exchange membrane and a cation exchange membrane which are alternately arranged between a positive electrode and a negative electrode like the traditional Electrodialysis (ED) and are separated by a special clapboard to form two systems of desalination, desalination and concentration; raw water enters a frequent reverse Electrodialysis (EDR) unit desalting channel, after a power supply is turned on, cations migrate to a negative electrode and only pass through a cation exchange membrane, anions migrate to a positive electrode and only pass through an anion exchange membrane, so that the saline water in the desalting channel is desalted, and the saline water in a concentration channel is concentrated. And is always circulated in a frequent reversed-polarity Electrodialysis (EDR) unit by means of a centrifugal pump. In the operation process, the EDR is automatically controlled through an electric program automatic control cabinet and a silicon controlled rectifier at regular intervals (generally 15-20 min), the polarities of the positive electrode and the negative electrode are mutually inverted once, so that the concentration chamber and the fresh chamber are exchanged, and the ion flow is reversely carried out. And simultaneously, the water inlet valve and the water outlet valve of the concentration chamber and the dilution chamber are automatically switched, so that the water supply and drainage systems of the concentration chamber and the dilution chamber are interchanged. And (4) continuing for 1-2 min after the polarity of the electrode is switched, returning unqualified fresh water into a concentrated water system, and then enabling the concentrated water and the fresh water to respectively go to the same way to recover normal operation. During the operation of the system, the salt content of the raw water in the desalting channel is continuously reduced, and the raw water overflows from the desalting liquid pool to the fresh water pool after reaching a set target value, so that the water in the fresh water pool can be used as reuse water to be supplemented to a circulating cooling water system of a cement plant. After the concentrated solution in the concentrated channel reaches a set target value, the concentrated solution overflows from the concentrated solution pool to a concentrated water pool, and the concentrated solution enters the next unit for treatment, and salt preparation by evaporative crystallization or flue spraying can be carried out;

the application firstly provides a frequent electrode Electrodialysis (EDR) desalination method without softening pretreatment for treating the circulating cooling water of the cement plant, fresh water generated by the frequent electrode Electrodialysis (EDR) unit can be directly used as reuse water to be supplemented into the circulating cooling water system of the cement plant, a small amount of concentrated water can be crystallized to prepare salt, and the concentrated water can also be sprayed into a flue for treatment. In the whole process, no lime, sodium hydroxide, sodium carbonate and other medicaments are required to be added, no hydrochloric acid or sulfuric acid is required to be added additionally for pH adjustment, and no softened precipitated sludge is generated. And scaling phenomenon can not occur when frequently inverting Electrodialysis (EDR) concentrated solution is used for treating circulating cooling water in a cement plant; the circulating cooling water of the cement plant is treated by adopting a frequent reverse Electrodialysis (EDR) technology, the recovery rate of fresh water is about 90%, the generated concentrated water is about 10%, and the concentration rate of the concentrated water is about 7-8 times; thereby realizing the concentration and reduction of pollutants and recycling water resources.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications and variations can be made in the embodiments or in part of the technical features of the embodiments without departing from the spirit and the scope of the invention.

Claims

1. Circulating cooling water's desalination processing system based on frequent electrode electrodialysis, its characterized in that: including pretreatment mechanism, pretreatment mechanism is including the clarification device in advance, multi-media filter equipment and the adsorption equipment who connects gradually, adsorption equipment connects the concentrated mechanism of frequent reverse pole electrodialysis, and the waste liquid that filters out by adsorption equipment gets into the concentrated mechanism of desalination and carries out the desalination concentration, the desalination liquid pond of the concentrated mechanism of frequent reverse pole electrodialysis is connected to the fresh water pond, the concentrated liquid pond of the concentrated mechanism of frequent reverse pole electrodialysis is connected to the dense pond, and the dense water outlet of dense pond is connected to crystallization mechanism, carries out evaporation crystallization salt manufacturing or flue spraying with dense water.

2. The system for desalting treatment of circulating cooling water based on electrodialysis reversal at frequent poles according to claim 1, wherein: the turbidity of the raw water treated by the pretreatment mechanism is less than 1 NTU.

3. The system for desalting treatment of circulating cooling water based on electrodialysis reversal at frequent poles according to claim 1, wherein: the adsorption device is an activated carbon adsorption device.