CN211097868U

CN211097868U - Water treatment equipment and system

Info

Publication number: CN211097868U
Application number: CN201921805355.2U
Authority: CN
Inventors: 陈栋; 张朝升; 洪庆辉
Original assignee: Guangzhou Weihoudai Environmental Protection Technology Co ltd
Current assignee: Guangzhou Weihoudai Environmental Protection Technology Co ltd
Priority date: 2019-10-24
Filing date: 2019-10-24
Publication date: 2020-07-28
Anticipated expiration: 2029-10-24

Abstract

The utility model discloses a water treatment device, which comprises an outer barrel, an inner barrel and a driving device, wherein the inner barrel is fixedly connected in the outer barrel, the driving device is used for driving the inner barrel to rotate in the outer barrel, the barrel bottom and the barrel wall of the inner barrel are provided with a plurality of dewatering holes, and the bottom of the outer barrel is provided with a concentrated solution outlet and a fresh water outlet; a feeding pipe is arranged at the upper part of the inner cylinder body; the liquid treated by the water treatment equipment is supercooled liquid. The liquid that water treatment facilities handled is the supercooled liquid, through with supercooled liquid through carry out supercooled water developments ice making, gravity filtration and centrifugal separation in water treatment facilities, realizes the separation of raw water fresh water and impurity. The equipment has the characteristics of low water treatment cost and wide applicability, and can be used for various industrial wastewater treatments (including strong acidity and strong basicity) and seawater desalination. The utility model also discloses a water treatment system who contains this water treatment facilities.

Description

Water treatment equipment and system

Technical Field

The utility model relates to a water treatment technical field, concretely relates to water treatment facilities and system.

Background

The electroplating wastewater contains a large amount of heavy metals which are harmful to the environment and human body. Meanwhile, the recovery value of the heavy metals is high. How to change waste into valuable and realize clean production is a key research direction of the electroplating wastewater treatment technology.

In the existing electroplating process, a reverse-flow multi-stage washing tank is arranged behind each electroplating bath to wash the plated part, so that the electroplating solution attached to the surface of the plated part can be washed off, and then the next electroplating procedure can be carried out. The washing wastewater of the plated parts generally exceeds 85 percent of the total wastewater of the electroplating plant, and is the largest object of electroplating wastewater treatment. After each electroplating process is finished, the plating piece is washed in a countercurrent multi-stage manner, and the electroplating solution attached to the surface of the plated piece is actually diluted step by step.

The development trend of electroplating wastewater treatment is clean production. Clean production means that advanced process technology and equipment are adopted, pollution is reduced from the source, resource utilization efficiency is improved, and generation and emission of pollutants in the processes of production, service and product use are reduced or avoided. The electroplating water washing wastewater is concentrated and reused in the electroplating bath, thus achieving the purpose of clean production. The electroplating water washing wastewater used in practical application is concentrated by reverse osmosis and evaporation concentration.

The reverse osmosis method is used for concentrating the nickel plating washing wastewater for the electroplating bath, and achieves good economic return. However, in the common electroplating process, the washing wastewater of the acid copper process, the coke copper process and the chromium plating process is strongly acidic with the pH value less than 2, and the washing wastewater of the alkali copper process and the zincate galvanizing process is strongly alkaline with the pH value more than 12, which are all beyond the allowable pH value range of the existing reverse osmosis membrane.

The evaporation concentration method is a method of concentrating the waste water by heating the waste water at normal pressure or reduced pressure to evaporate the water in the solvent. The concentrated solution can be returned to the plating bath, and the evaporated water vapor can be used as cleaning water after being condensed and recovered. However, the evaporation concentration method has large energy consumption and high cost. At present, in electroplating wastewater treatment, evaporation concentration method is rarely used alone, and is generally used as a link in combined treatment, such as treatment of reverse osmosis concentrated solution.

In the process of crystallization, impurities in water can be automatically removed to keep the water pure, and the freezing method water treatment technology is based on the basic principle. The freezing water treatment method has wide application range, almost has no selectivity to the waste water, and has obvious advantages for treating the waste water which is difficult to degrade (particularly the toxic and heavy metal waste water). The energy consumption of the freezing method is far lower than that of processes such as concentration and evaporation. The latent heat of vaporization at 100 ℃ is 2257.2kJ/kg, the latent heat of solidification of water is 335kJ/kg, and the theoretical energy consumption of evaporation concentration is 7 times that of freezing concentration. The freezing concentration adopts the normal pressure heat pump technology, and the average freezing energy consumption of the heat pump is 1/3 of the theoretical energy consumption. When the refrigerating end (evaporator) of the heat pump cools and makes ice, the similar heat can be transferred to the heat dissipation end (condenser) for melting ice, and the ice can be melted without extra heat energy. And evaporation concentration needs an additional cold source to cool the steam.

Supercooled water dynamic ice making is the latest ice making technology used in ice storage air conditioners. After the water reaches the freezing point temperature (the freezing point temperature of tap water under the standard atmospheric pressure is 0 ℃), the water cannot be frozen immediately, the supercooling phenomenon can occur, and the safe supercooling degree of the tap water is-3.8 ℃. Supercooled water is in a metastable state and ice crystals appear when the temperature of the water is lower than the supercooling degree. However, when such metastable states are artificially destroyed, ice crystals will also form without exceeding the supercooling degree. Because the supercooling degree is not needed to be reached to form ice, and the heat transfer efficiency between small ice crystals and solid and liquid is high, compared with other existing ice making methods, the supercooled water dynamic ice making and freezing method has higher ice making rate and energy efficiency. The supercooled water dynamic ice making method can form fine ice crystals with higher purity. The process of making ice by using supercooled water is a dynamic process, ice crystals and water continuously move mutually, and the ice crystals and the water are more easily separated automatically.

Disclosure of Invention

The utility model aims to overcome the shortcomings of the prior art and provide a water treatment device and a system.

In order to achieve the above purpose, the utility model adopts the following technical scheme: a water treatment device comprises an outer barrel, an inner barrel and a driving device, wherein the inner barrel is fixedly connected in the outer barrel, the driving device is used for driving the inner barrel to rotate in the outer barrel, a plurality of dewatering holes are formed in the barrel bottom and the barrel wall of the inner barrel, filter cloth is arranged on the inner wall of the inner barrel, and a concentrated solution outlet and a fresh water outlet are formed in the bottom of the outer barrel; a feeding pipe is arranged at the upper part of the inner cylinder body; the liquid treated by the water treatment equipment is supercooled liquid.

What water treatment facilities handled is supercooled liquid, form the condition of supercooled water developments ice-making through the mobile state with supercooled liquid from feed pipe flow to interior barrel, along with the flow of supercooled water, the inner wall of barrel forms the ice crystal including gradually, impurity in the raw water then flows from the dehydration hole with the liquid that does not freeze and forms the concentrate, along with the increase of time, the ice crystal is more and more, after the ice crystal reaches the take the altitude, barrel centrifugal motion in the drive arrangement drive is deviate from the remaining impurity centrifugal separation on ice crystal surface, obtain ice crystal and the concentrate that contains impurity concentration low, realize the separation of fresh water and impurity in the raw water. And finally, the concentrated solution flows out from a concentrated solution outlet, and the ice crystals can flow out from a fresh water outlet after being melted or added with fresh water to form ice slurry. The equipment has the characteristics of low water treatment cost and wide applicability, and can be used for various industrial wastewater treatments (such as the freezing treatment of electroplating water washing wastewater with strong acidity, subacidity and strong basicity, and the problem that the electroplating wastewater treatment meets the requirement of clean production) and seawater desalination.

The aperture of the filter cloth is smaller than that of the dewatering holes. The aperture size of the filter cloth can be designed to be the size which can lead the concentrated solution to flow out and lead the ice crystals to be retained in the inner cylinder body.

Preferably, the liquid is electroplating wastewater, and the temperature of the supercooled liquid is-1 to-2.5 ℃. For electroplating wastewater, the impurity removal efficiency is higher when the temperature of the supercooled liquid is-1 to-2.5 ℃, and especially the impurity removal efficiency is highest when the temperature of the supercooled liquid is-1.5 to-2.5 ℃.

Preferably, at least one partition plate is arranged in the inner cylinder body, and the partition plate is fixedly connected with the inner wall of the inner cylinder body through the central axis of the inner cylinder body or the central axis parallel to the inner cylinder body. On one hand, the arrangement of the partition plate is to avoid the pollution of the prepared ice crystals by overflowing wastewater, the partition plate is fixedly arranged in the inner cylinder body to divide the inner cylinder body into different areas, when the ice crystals in one area reach a certain height, the feeding pipe is moved to the other area to feed stock solution, and the impurity removal rate is higher; on the other hand, raw water entering the water treatment equipment from the feeding pipe impacts the partition plate to destroy stability, a condition of dynamically making ice by the supercooled water is formed, and ice crystals are formed, otherwise, if the supercooled water directly flows into the inner cylinder body from the feeding pipe, the ice crystals are difficult to form the partition plate due to the buffering of liquid in the inner cylinder body, and the partition plate is preferably arranged in a mode of passing through the central axis of the inner cylinder body. The height of the partition plate is preferably lower than that of the inner cylinder. Preferably, the pump pressure of the circulating pump can make the raw water of the feeding pipe impact the partition plate, and a certain impact force destroys the stability of the supercooled water.

Preferably, a solid inductor is arranged in the inner cylinder body and electrically connected with the driving device, and when ice crystals in the inner cylinder body reach a set height, the solid inductor controls the driving device to drive the inner cylinder body to rotate by a set angle; when ice crystals in each region in the inner cylinder body reach a set height, the solid inductor controls the concentrated solution outlet to be opened and controls the driving device to drive the inner cylinder body to rotate centrifugally.

The turned angle is decided according to the region that the baffle of interior barrel divided, turned angle satisfies and makes the inlet pipe mouth of pipe be located the top in another region after rotating, if the baffle sets up to 2 the central axis through interior barrel and with the inner wall rigid coupling of interior barrel, two baffle mutually perpendicular, the baffle is equallyd divide into four regions with interior barrel promptly, reach the settlement height when the ice crystal in one of them region, can set for barrel rotation 90 in the solid inductor control drive arrangement drive, make the inlet pipe mouth of pipe be located the top in another region and continue to form the ice crystal, until the ice crystal in every region all reaches the settlement height, the export of solid inductor control concentrate is opened and is discharged concentrate and control drive arrangement drive interior barrel centrifugation rotation. The treatment capacity of the water treatment equipment is determined according to the volume of the inner cylinder body.

Preferably, a water distributor is arranged above the inner barrel and used for providing fresh water, so that the fresh water is mixed with the ice crystals to form ice slurry which falls off from the inner barrel and flows out.

Preferably, the bottom of the inner cylinder body is also provided with a raw water outlet, and the raw water outlet is connected with a feeding pipe. In the process of crystallizing the supercooled liquid, the uncrystallized liquid is circulated back to the feeding pipe to be continuously crystallized in a circulating way, the concentration of the concentrated liquid is higher and higher along with the prolonging of the time, and a refrigerating system is preferably arranged between the raw water outlet and the pipe orifice of the feeding pipe and is used for compensating heat loss in the flowing process and keeping the temperature of the liquid.

An object of the utility model is to provide a water treatment system, including the aforesaid water treatment facilities and refrigerating system, refrigerating system is used for making the stoste into subcooled liquid.

Preferably, the refrigeration system comprises a raw water precooling regulating reservoir, a liquid outlet of the raw water precooling regulating reservoir is connected with the water treatment equipment, a raw water outlet is arranged on the water treatment equipment, and the raw water outlet is sequentially connected with the evaporator and a feed pipe of the water treatment equipment through a circulating pump; the concentrated solution outlet is connected with the concentrated water tank sequentially through the first condensation tank and the raw water pre-cooling regulation tank, and the fresh water outlet is connected with the fresh water tank sequentially through the second condensation tank and the raw water pre-cooling regulation tank.

Forming concentrated solution and ice crystals in the water treatment equipment, opening a concentrated solution outlet to discharge the concentrated solution, and allowing the concentrated solution to flow through a first condensation tank and a raw water precooling regulation tank to a concentrated water tank; ice crystals are mixed with fresh water and then are mixed through stirring or a driving device is started to enable an inner cylinder body to rotate and mix to form ice slurry, a fresh water outlet is opened to discharge the ice slurry to flow through a second condensation tank and a raw water precooling adjusting tank to a fresh water tank, raw water in the precooling adjusting tank is subjected to heat exchange with low-temperature concentrated solution and low-temperature fresh water and then is subjected to primary cooling, then the raw water enters water treatment equipment, the raw water flows out of a raw water outlet on the water treatment equipment and then flows into an evaporator, the raw water flows out of the evaporator and then enters the water treatment equipment through a feeding pipe, and the raw water circulates between the water treatment equipment and the evaporator until the.

Preferably, the refrigeration system further comprises an auxiliary condenser, and a refrigerant of the auxiliary condenser sequentially flows through the throttle valve, the evaporator, the compressor, the first condensation tank and the second condensation tank through a pipeline. The auxiliary condenser is used for refrigerating the system at the initial starting stage of the system and auxiliary heat dissipation in the working process of the system. Preferably, the refrigerant pipelines in the first condensation tank and the second condensation tank are arranged at the bottoms of the first condensation tank and the second condensation tank.

Preferably, a fresh water circulating pipe is arranged at the bottom of the second condensation tank and is connected with the water distributor. And circulating the fresh water after the ice crystals are melted for separating the ice crystals in the inner cylinder body to form ice slurry.

Preferably, the inlet pipes of the first condensation tank and the second condensation tank are arranged above the highest liquid level, the outlet pipe is arranged at the bottom, and the top of the outlet pipe is provided with a siphon breaking hole.

Preferably, the refrigeration system further comprises a raw water heating system, and the raw water heating system is used for heating the raw water entering the circulating pump to a temperature of more than or equal to 0 ℃. The ice crystal blocks up the circulating pump and the pipeline in front of the circulating pump, which is a common problem in the existing supercooled water dynamic ice making process, so that raw water forms supercooled water after being refrigerated by the evaporator, the temperature of the supercooled water is still lower after passing through the water treatment equipment, if the supercooled water is continuously circulated to the evaporator, the pipeline in front of the circulating pump and the circulating pump easily forms ice crystals to block up the circulating pump, and therefore, a raw water temperature rising system is arranged to heat up the raw water after the water treatment equipment and before the circulating pump.

Preferably, a raw water branch is arranged on a water outlet pipeline of the circulating pump, and the raw water branch flows through the auxiliary condenser and returns to a water inlet pipeline of the circulating pump. The temperature is preferably raised in the above manner, the temperature of the temperature rise can be controlled to be about 0 ℃, and the energy of the system is saved.

Adopt the water treatment system's water treatment method includes following step:

s1, cooling the raw water to obtain a supercooled liquid, and freezing the supercooled liquid into ice crystals by adopting a supercooled water dynamic ice making method;

s2, separating ice and concentrated raw water from the supercooled liquid by adopting gravity filtration;

and S3, removing the concentrated raw water attached to the ice surface through centrifugation to obtain concentrated raw water and low-concentration ice crystals.

The water treatment system adopts the raw water to form the supercooled liquid and adopts dynamic ice making, gravity filtering and centrifugal separation to separate impurities and fresh water. The inventor finds that the ice crystals formed by dynamically making ice from the waste water through supercooling water have high water purity, the amount of impurities wrapped in the ice crystals is small, the impurities mainly exist in the concentrated waste water attached to the surfaces of the ice crystals and the concentrated waste water existing in gaps between the ice crystals, the high impurity removal rate can be realized through the gravity filtration and centrifugal separation method, and the obtained low-concentration ice crystals can be separated and purified again according to actual needs.

Preferably, the concentrated raw water and/or low-concentration ice crystals are used for raw water precooling treatment. The water treatment method adopts the raw water to form the supercooled liquid and adopts dynamic ice making, gravity filtering and centrifugal separation to separate impurities from fresh water.

Preferably, the thickness of the low-concentration ice crystals is 0.5-1 mm. The inventor finds that the ice crystal removal rate effect is high when the thickness is 0.5-1 mm.

The water treatment method of the water treatment system comprises the following specific steps: the method comprises the following steps that raw water enters water treatment equipment after being initially cooled in a precooling adjusting tank, flows out from a raw water outlet on the water treatment equipment and then flows into an evaporator, the evaporator flows out and then enters the water treatment equipment from a feeding pipe, the raw water circulates between the water treatment equipment and the evaporator until the temperature is reduced to form supercooled liquid, ice crystals are formed, and the liquid without the ice crystals is concentrated liquid; opening a concentrated solution outlet to discharge concentrated solution, and enabling the concentrated solution to flow through a first condensation tank and a raw water precooling regulation tank to a concentrated water tank; the ice crystals are mixed with fresh water and then the inner cylinder body is rotated and mixed to form ice slurry through stirring or starting a driving device, a fresh water outlet is opened to discharge the ice slurry to flow through a second condensation tank and a raw water precooling adjusting tank to a fresh water tank, and the raw water in the precooling adjusting tank is subjected to heat exchange with low-temperature concentrated solution and low-temperature fresh water to be primarily cooled.

The beneficial effects of the utility model reside in that: the utility model provides a water treatment device. Raw water that water treatment facilities handled is supercooled liquid, through with supercooled liquid through carrying out supercooled water developments ice making, gravity filtration and centrifugal separation in water treatment facilities, realizes the separation of fresh water and impurity in the raw water. The equipment has the characteristics of low water treatment cost and wide applicability, and can be used for various industrial wastewater treatments (for example, three electroplating water-washing wastewater with strong acidity, subacidity and strong basicity are subjected to freezing treatment, so that the problem that the electroplating wastewater treatment meets the requirement of clean production) and seawater desalination. The utility model also provides a water treatment system, water treatment system can realize water treatment energy-conservingly high-efficiently, realizes the recycle of concentrated water and fresh water.

Drawings

FIGS. 1 and 2 are schematic structural views of a water treatment apparatus according to embodiment 1;

FIG. 3 is a schematic view of the structure of a water treatment system according to embodiment 2;

FIG. 4 is a schematic view of a water-filling state of the water treatment apparatus according to embodiment 1;

FIG. 5 is a schematic view showing a freeze-separated state of the water treatment apparatus according to example 1;

FIG. 6 is a schematic view showing a centrifugal separation state of the water treatment apparatus according to example 1;

FIG. 7 is a schematic view showing the structure of a second condensation tank in example 2;

FIG. 8 shows the results of an ice crystal centrifugal dehydration experiment for washing wastewater from a nickel plating process;

wherein, 1, water treatment equipment; 2. a raw water precooling regulating pool; 3. an evaporator; 4. a first condensation tank; 5. a concentration water tank; 6. a second condensation tank; 7. a fresh water pool; 8. an auxiliary condenser; 9. a throttle valve; 10. a compressor; 11. a water distributor; 12. a filter; 13. a first circulation pump; 14 a second circulation pump; 15. a flow regulating valve; 16. a third circulation pump; 101. an outer cylinder; 102. an inner cylinder; 103. a drive device; 104. a concentrated solution outlet; 105. a fresh water outlet; 106. a feed pipe; 107. filtering cloth; 108. a partition plate; 109. a water distributor; 110. a raw water outlet; 111. a support; 601. a water inlet pipe of the second condensation tank; 602. a water outlet pipe of the second condensation tank; 603. siphoning off the hole; 604. fresh water circulating pipe.

Detailed Description

For better illustrating the objects, technical solutions and advantages of the present invention, the present invention will be further described with reference to the following embodiments.

Example 1

In an embodiment of the water treatment apparatus of the present invention, a schematic structural diagram of the water treatment apparatus of the present embodiment is shown in fig. 1-2; the dewatering device comprises an outer barrel 101, an inner barrel 102 and a driving device 103, wherein the inner barrel 102 is fixedly connected in the outer barrel 101, the driving device 103 is used for driving the inner barrel 102 to rotate in the outer barrel 101, a plurality of dewatering holes are formed in the barrel bottom and the barrel wall of the inner barrel 102, and a concentrated solution outlet 104 and a fresh water outlet 105 are formed in the bottom of the outer barrel; the upper part of the inner cylinder body is provided with a feed pipe 106.

The inner wall of the inner cylinder 102 is provided with a filter cloth 107, and the aperture of the filter cloth 107 is smaller than that of the dewatering holes.

The inner cylinder is internally provided with two partition plates 108 which pass through the central axis of the inner cylinder and are fixedly connected with the inner wall of the inner cylinder, and the two partition plates are mutually vertical, namely, the partition plates divide the inner cylinder into four areas.

A water distributor 109 is arranged above the inner cylinder 102, and the water distributor 109 is used for providing fresh water to be mixed with ice crystals to form ice slurry to fall off from the wall of the inner cylinder and flow out.

A solid inductor (not shown in the figure) is arranged in the inner cylinder 102 and is electrically connected with the driving device 103, when ice crystals in the inner cylinder reach a set height, the solid inductor controls the driving device to drive the inner cylinder 102 to rotate by a set angle, so that an area which does not reach the set height is positioned below the feeding pipe, the ice crystals are continuously formed, and the produced ice crystals can be prevented from being polluted by overflowed wastewater; when the ice crystals in each area in the inner cylinder body reach a set height, the solid inductor controls the concentrated solution outlet to be opened and controls the driving device to drive the inner cylinder body 102 to rotate centrifugally.

The bottom of the inner cylinder 102 is also provided with a raw water outlet 110, and the raw water outlet 110 is connected with the feeding pipe 106 through a refrigerating device (not shown in the figure). A bracket 111 is arranged between the inner cylinder and the outer cylinder.

When the water treatment equipment works, the flow state of the supercooled liquid flowing from the feed pipe 106 to the inner cylinder 102 forms the condition of dynamic ice making by the supercooled water, ice crystals are gradually formed on the inner wall of the inner cylinder along with the flow of the supercooled water, impurities in raw water flow out from the dehydration holes to form concentrated solution, and the concentrated solution enters the feed pipe 106 from the raw water outlet 110 through the refrigeration device and circularly enters the inner cylinder 102; along with the increase of time, ice crystals are more and more, after the ice crystals reach a set height, the solid inductor controls the opening driving device to drive the inner cylinder body 102 to rotate 90 degrees, so that the pipe opening of the feeding pipe is positioned above the other region to continuously form the ice crystals until the ice crystals in the four regions reach the set height, the solid inductor controls the opening of the concentrated solution outlet 104, then the driving device 103 is controlled to drive the inner cylinder body 102 to centrifugally rotate, impurities remained on the surfaces of the ice crystals are centrifugally separated out, the ice crystals and the concentrated solution containing low impurity concentration are obtained, and the separation of fresh water and the impurities in the raw water is realized. The concentrated solution is discharged from the concentrated solution outlet 104, ice crystals can be melted or the water distributor 109 is opened to put fresh water, the driving device is started to rotate the inner cylinder body, so that the fresh water and the ice crystals are mixed to form ice slurry, and then the ice slurry flows out from the fresh water outlet 105. The equipment can be used for various industrial wastewater treatments (such as strong-acid, slightly-acid and strong-alkali electroplating wastewater treatment) and seawater desalination.

Example 2

In an embodiment of the water treatment system of the present invention, a schematic structural diagram of the water treatment system of the present embodiment is shown in fig. 3; the water treatment system comprises the water treatment equipment 1 and a refrigeration system in embodiment 1, wherein the refrigeration system comprises a raw water pre-cooling regulation pool 2, a liquid outlet of the raw water pre-cooling regulation pool 2 is connected with the water treatment equipment 1 through a first circulating pump 13, a raw water outlet is formed in the water treatment equipment 1, and the raw water outlet is connected with a feeding pipe of the water treatment equipment 1 through a second circulating pump 14 and an evaporator 3; the concentrated solution outlet is connected with the concentrated water tank 5 sequentially through the first condensation tank 4 and the raw water pre-cooling regulation tank 2, and the fresh water outlet is connected with the fresh water tank 7 sequentially through the second condensation tank 6 and the raw water pre-cooling regulation tank 2.

The refrigeration system further comprises an auxiliary condenser 8, and a refrigerant of the auxiliary condenser 8 sequentially flows through a throttle valve 9, the evaporator 3, the compressor 10, the first condensation tank 4 and the second condensation tank 6 through pipelines. The auxiliary condenser 8 is used for refrigerating the system at the initial stage of system starting and auxiliary heat dissipation in the working process of the system.

Be equipped with the raw water branch road on the outlet conduit of second circulating pump, the raw water branch road flows through auxiliary condenser 8 and gets back to on the inlet tube way of second circulating pump, be equipped with flow control valve 15 on the raw water branch road, through the raw water temperature before adjusting the flow control circulating pump. The raw water branch is arranged for heating the raw water flowing out of the water treatment equipment and before entering the circulating pump to be more than or equal to 0 ℃.

The liquid outlet of the second condensation tank 6 is also connected with the water distributor 11.

The working flow of the wastewater treatment system described in this embodiment is illustrated by taking the treatment of acid copper electroplating washing wastewater as an example:

1 Unit of 25 ℃ wastewater raw Water (Cu)²⁺Content 5.13 g/L) is filtered by the filter 12 and then sent to the raw water precooling adjusting pool 2, and the raw water is cooled to 11 ℃ after passing through the raw water precooling adjusting pool 2;

step one, water injection: the first circulation pump 13 is turned on, and 1 unit of raw water with the temperature of 11 ℃ is sent to the water treatment device 1, as shown in figure 4;

step two, freezing and separating: the second circulation pump 14 and the auxiliary condenser 8 are opened, and the waste water raw water is cooled at the evaporator 3 of the refrigeration plant. When the raw water temperature of the waste water reaches about-3 ℃ to become the supercooled waste water, the supercooled waste water is sprayed on the partition plate 108 through the feeding pipe 106, the stability of the supercooled waste water is damaged by impact force, small ice crystals begin to form, the ice crystals are separated from the waste water through the filter cloth 107 and the dehydration holes on the inner cylinder 102, the ice crystals do not enter the refrigeration system, the temperature of the raw water without the formation of the ice crystals is raised to about-1 to-2 ℃, a part of the raw water continuously flows into the evaporator 3 through the second circulating pump 14 to be cooled to about-3 ℃ to become the supercooled waste water, and a part of the raw water is heated to about 0 ℃ through the raw water branch auxiliary condenser and returns to the water. Ice crystals accumulate in the upper inner barrel 102 and the wastewater is gradually concentrated in the lower portion of the disposer. The inner cylinder 102 is divided into 4 grids by the partition plates 108, when 1 grid of ice crystals is fully stacked, the driving device rotates the inner cylinder for 90 degrees, and ice making is started in the next grid of the inner cylinder 102, so that the made ice crystals are not polluted by waste water. After 4 lattices of the inner cylinder 102 are fully accumulated with ice crystals, more than 80 percent of the raw wastewater is frozen into the ice crystals, and 20 percent of the raw wastewater forms concentrated water at the lower part of the processor. See fig. 5.

And thirdly, centrifugal separation. And opening a concentrated solution outlet valve, making the concentrated solution at the lower part of the water treatment equipment 1 flow through the first condensation tank 4 and the raw water precooling regulation tank 2 in a pipeline, and finally entering the concentrated water tank 5. Then, the motor is started to rotate the inner cylinder body 102 at a high speed, centrifugal dehydration is carried out, and the waste water between the ice crystals and attached to the surfaces of the ice crystals is thrown out of the inner cylinder body 102. The purity of the ice crystals can be controlled by the time of centrifugal dehydration. The experiment shows that the Cu in the raw wastewater is dehydrated for 2 minutes in a centrifugal way²⁺The removal rate reaches 90 percent, and Cu in the ice crystals² ⁺Cu at a concentration of 0.51 g/L²⁺The concentration is less than the concentration of the washing water (Cu) of the first-stage washing tank²⁺Content 5.13 g/L), can be reused to replenish fresh water in the first stage water wash tank, wherein the weight of ice crystals is 70% of that of the raw wastewater water, and the total weight of the formed concentrated water is 30% of that of the raw wastewater water, see fig. 6.

Fourthly, discharging the ice crystals. Closing the concentrated solution outlet valve, opening a fresh water outlet at the bottom of the water treatment equipment 1, then starting the driving device to rotate the inner cylinder body at a slow speed, opening the third circulating pump 16 to send low-temperature fresh water (tap water is adopted during the first operation) in the fresh water pool 7 into the inner cylinder body 102 through the water distributor 11, and flushing ice crystals in the inner cylinder body 102 to form ice slurry. The ice slurry flows into the fresh water pool 7, and after the ice crystals in the inner cylinder 102 completely enter the fresh water pool 7, the third circulating pump 16 is closed, and the fresh water outlet at the bottom of the water treatment device 1 is closed.

The volume of the second condensation tank 6 is 1.5 units, and the amount of fresh water mixed with the pure ice crystals formed after the centrifugal dehydration of the inner cylinder 102 is 1 time of that of the pure ice crystals. The inlet tube 601 of the second condensation pool is used for feeding water on the highest liquid level, the outlet tube 602 of the second condensation pool adopts an overflow water outlet mode, the water quantity exceeding the highest water level is discharged to the fresh water pool 7 in an overflow mode, the water quantity in the second condensation pool 6 is guaranteed to be unchanged, and the second condensation pool 6 is guaranteed to have enough heat exchange water quantity. Because of the second condensation pool 6 has 0.7 units of ice crystal inflow, the ice crystal is less than water because of the specific gravity, can float on the surface of the pool, in order to prevent the ice crystal from blocking the outlet pipe, the outlet pipe 602 adopts the outlet water from the bottom of the pool, the pipe top sets up the siphon and destroys the hole 603, when the pool water level is less than the siphon and destroys the hole, the siphon is destroyed, the outlet pipe no longer goes out water. The fresh water circulation pipe 604 (the pipe connected to the water distributor) uses bottom water. And the heat exchange coil of the second condensation tank 6 is arranged at the lower part of the water level. See fig. 7.

The first condensation tank 4 is different from the second condensation tank 6 only in that a fresh water circulation pipe is not provided and the other arrangement is the same as that of the second condensation tank 6. The first condensation tank 4 also has a volume of 1.5 units, i.e. the liquid (0 ℃) supplied to the auxiliary condenser for heat exchange amounts to 3 units.

If the system is completely closed, i.e. adiabatic without heat exchange with the outside, the heat absorbed by the evaporator 3 and the heat released by the first and

second condensation tanks

4 and 6 are the same. However, in practice, particularly for the first condensation tank 4 and the second condensation tank 6, since the temperature is 0 ℃ for a long time and the atmospheric temperature is 33 ℃, heat preservation cannot be actually performed until the atmospheric heat is not transferred to the water at 0 ℃ in the condenser. In order to balance the heat transfer, the refrigeration cycle is provided with an auxiliary condenser 8 and a corresponding auxiliary refrigeration system, and the heat transferred by the atmosphere is transferred to the atmosphere.

The 0 ℃ refrigerant flows out of the auxiliary condenser 8, is cooled to-6 ℃ through the throttle valve 9, is heated to-3 ℃ through the evaporator 3, is heated to 5 ℃ through the compressor 10, passes through the first condensation tank 4 and the second condensation tank 6, and then returns to the auxiliary condenser 8.

The water treatment system of the embodiment is used for treating electroplating wastewater, and the treatment method comprises the following steps:

s3, removing the concentrated wastewater attached to the ice surface through centrifugation to obtain concentrated wastewater and low-concentration ice crystals;

s4, if necessary, repeating steps S1 to S3 with the concentrated raw water obtained in step S3.

1. According to the method, the concentration of each component of solute of the water washing wastewater of the primary water washing tank is actually measured according to the sampling of an electroplating plant, the water washing wastewater of the simulated primary water washing tank with the concentration close to 100L is configured by referring to the theoretical formula of electroplating solution, the water treatment system described in the embodiment 2 is used for carrying out the supercooled water dynamic ice making freezing test, the solid-liquid separation mode is gravity static separation, ice powder is filtered and separated through a plastic separation net and filter cloth at the position of 1/4 at the lower part of the inner cylinder body, and the concentrated wastewater flows to the bottom of the ice making barrel by.

The test results are shown in tables 1-3.

TABLE 1 results of the treatment of the acid copper process washing wastewater by freezing

TABLE 2 results of the treatment of the washing wastewater of the nickel plating process by freezing

Serial number		Ni²⁺Concentration of	SO4^2-Concentration of	Cl^-Concentration of
					1	Waste water raw water (mg/l)	1323	2377	485
2	Shut down for 5 minutes ice and melt water (mg/l)	303	625	148
					3	The ice-melt water and the ice-melt water are removed within 5 minutes of the machine halt	77.1％	73.7％	69.4％
4	Gravity separation 30 min concentrated water (mg/l)	3757	6200	1230
					5	Gravity separation for 30 minutes ice and water (mg/l)	196	517	116
6	Removal rate of ice-melt water by gravity separation for 30 minutes	85.2％	78.3％	76.1％
					7	Gravity separation for 18 hours ice and water (mg/l)	27.8	149.8	33.5
8	Gravity separation removal rate of ice-melt water for 18 hours	97.9％	93.7％	93.1％

TABLE 3 result of the treatment of the washing wastewater of zincate galvanizing process by freezing

Serial number		Zn²⁺Concentration of	OH^-Concentration of
				1	Waste water raw water (mg/l)	8834	40110
2	Gravity separation 30 min concentrated water (mg/l)	22173	96531
				3	Gravity separation for 30 minutes ice and water (mg/l)	2182	11151
4	Removal rate of ice-melt water by gravity separation for 30 minutes	75.3％	72.2％
				5	Gravity separation for 18 hours ice and water (mg/l)	539	3770
6	Gravity separation removal rate of ice-melt water for 18 hours	94.0％	90.6％

From tables 1 to 3, the analysis results of the water samples are as follows: the supercooled water dynamic ice-making freezing method has similar treatment results for strong-acid electroplating wastewater, micro-acid electroplating wastewater and strong-acid electroplating wastewater; and (4) comparing the removal rates of the water washing wastewater with ice-melting water, and plating nickel, acid copper and zincate zinc.

Ice-melt water pair Ni formed by nickel plating water washing wastewater²⁺The removal rate of the ice-melt water is improved by 12.7 percent compared with the removal rate of the ice-melt water in 5 minutes after the machine is stopped, wherein the removal rate of the ice-melt water is improved by 12.7 percent when the gravity separation is carried out for 18 hours and the removal rate of the ice-melt water is improved by 20.8 percent when the machine is stopped for 30 minutes. Thus, it can be seen that: the ice crystals formed by the supercooled water dynamic ice making of the wastewater have high water purity and are wrapped in the ice crystalsThe amount of impurities carried by the wastewater is small, and the impurities are mainly in the concentrated wastewater attached to the surfaces of the ice crystals and the concentrated wastewater existing in gaps among the ice crystals.

Tests show that after the gravity solid-liquid separation is carried out for 18 hours, the volume of the ice crystals becomes 40 percent of the original volume, the ice crystals become hard, and block appears, but the permeability is greatly improved compared with that of soft flocculent ice crystals. 2000ml ice crystal lump was completely thawed to give 1610ml water, and considering that the volume of water frozen into ice would increase by 10%, the ice crystal lump void fraction would be 14.2%.

The time of gravity static separation is too long, taking the nickel plating water washing wastewater freezing test as an example, the Ni is separated by gravity for 30 minutes²⁺The removal rate can reach 85.2 percent, and the ice and water Ni is statically separated by gravity for 18 hours²⁺The removal rate can reach 97.9 percent, so the concentrated wastewater attached to the surfaces of the ice crystals and the concentrated wastewater existing in gaps among the ice crystals are removed by a centrifugal separation and gravity separation method.

2. Centrifugal separation

The centrifugal solid-liquid separation test adopts: the rotating speed is 820 rpm, the rated input power is 200W, and the maximum dewatering weight is 4 kg. 2847g of nickel plating process washing wastewater ice crystals generated by a supercooled water dynamic ice making method are put into a filter bag and put into a centrifugal dehydrator for dehydration. Waste water raw water Ni²⁺Ni concentration of 1323 mg/L before ice crystal dehydration²⁺The concentration 303 mg/L, see Table 4.

TABLE 4 centrifugal dewatering experiment for water washing wastewater ice crystal of nickel plating process

FIG. 8 shows the results of ice crystal centrifugal dehydration experiment of the washing wastewater of nickel plating process, and it can be seen from FIG. 8 that (1), dehydrated weight reduction and dehydrated Ni²⁺The removal amount is basically in a direct proportion relation. (2) The longer the centrifugal dehydration time, the more the dehydration amount is rapidly decreased. Dewatering for 2 min, ice melting water Ni²⁺The concentration of Ni in the wastewater is reduced to 136 mg/L and is smaller than the measured Ni in the wastewater of the primary rinsing bath of the electroplating plant ²⁺1/10 of 1580 mg/L concentration, ice and melt water can be used for supplementing in first-grade water washing tankAnd filling with fresh water.

By this method, a maximum freezing ratio of about 80% can be achieved, i.e. 80% by weight of the waste water is forming ice crystals and 20% by weight is forming concentrated waste water. After 2 minutes of centrifugal dehydration, the concentrated wastewater separated from ice was 23% by weight of the original ice-water mixture, and it was calculated that the total weight of the concentrated wastewater after solid-liquid separation was 38% by weight of the original wastewater.

After primary freezing treatment and centrifugal dehydration, the concentration of the concentrated solution is far away from the concentration of the electroplating solution of the electroplating bath, taking the freezing treatment result of the washing wastewater of the nickel plating process as an example, the concentrated water Ni²⁺Concentration of 3757 mg/L, Ni from the plating bath²⁺The concentration 33000 differed by 778%, requiring a second concentration.

Experiments show that Ni is mixed with²⁺Washing the wastewater with the concentration of 3757 mg/L in the simulated nickel plating process, performing dynamic ice making by using supercooled water to form ice crystals, and performing centrifugal dehydration for 2 minutes to obtain the final Ni in the ice-melt water²⁺The concentration is 725 mg/L, the removal rate is 81 percent, and the concentration accounts for the original wastewater (Ni)²⁺Concentration 1323 mg/L) 24% by weight Ni-Ice Water²⁺The concentration value far exceeds the Ni allowable discharge standard of 0.5 mg/L specified in China, and the partial ice melting water is sent to a wastewater treatment station for treatment and then discharged.

Final concentration of Ni from waste water²⁺The concentration is 8857 mg/L, and the waste water is raw waste water (Ni)²⁺1323 mg/L), the working temperature of the plating solution in the nickel electroplating process is 55-60 ℃, the evaporation capacity of pure water is large, pure water needs to be supplemented simultaneously, and when the supplemented plating solution is taken out by a plated part, the concentration of the supplemented plating solution is about 80 percent of the formula concentration, namely Ni²⁺Concentration of 24960 mg/L Ni of final concentrated wastewater of second freezing treatment²⁺The concentration of 8857 mg/L is 35.5% of 24960 mg/L, the concentration rate is 2.8, and the waste water (Ni) is obtained after evaporation concentration²⁺Concentration 1323 mg/L) weight percent.

3. Energy consumption calculation

The latent heat of solidification of water was 0.093 kwh/kg. The amount of waste water of the first freezing treatment by adopting the method of the embodiment is 100kg, the amount of concentrated waste water of the second freezing treatment is 38kg, and the theoretically required refrigerating capacity is 12.8 kwh. The experiment adopts an air-cooled ice maker, waste water exchanges heat with air at 25 ℃, the refrigerating capacity is 15kw, the refrigeration COP is 4.0, the comprehensive COP (including circulating pump energy consumption) is 3.0, the input power is 5kw, 138kg of waste water is frozen, and the actual measurement energy consumption is 6.8 kwh.

The energy efficiency ratio COP of the refrigeration equipment is 0.6 × (273+ evaporation temperature)/(condensation temperature-evaporation temperature), the lower the condensation temperature is, the higher the COP is, the condensation temperature of the air-cooled ice making machine in the experiment is 30 ℃, the evaporation temperature is-8 ℃, actual freezing method water treatment equipment (such as freezing method seawater desalination equipment) adopts waste water and 0 ℃ ice generated in the last batch of freezing treatment for heat exchange, the ice generated in the last batch of freezing treatment is melted, the condensation temperature of the freezing treatment equipment is 9 ℃, the refrigeration COP is calculated to be 8.0, the comprehensive COP is 4.8, the input power is 3.1kw, and the energy consumption for freezing 138kg of waste water is 4.3 kwh.

The energy consumption of the centrifugal dehydrator adopted in the experiment is 0.2kwh per hour, and the energy consumption of the centrifugal dehydrator is 0.0067kwh after 2 minutes. 2 times of centrifugal dehydration, and the total energy consumption of the centrifugal dehydration is 0.013 kwh.

The latent heat of vaporization of water at 100 ℃ was 0.63 kwh/kg. After the second freezing treatment, 14kg of high-concentration wastewater is generated and is evaporated and concentrated to become 5kg of ultrahigh-concentration wastewater, and the evaporation capacity of water is 9 kg. The energy consumption for evaporation and concentration in the experiment is 3.6 kwh.

100kg of electroplating wastewater is treated. In the experiment, total energy consumption is 6.8+0.013+ 3.6-10.4 kwh by freezing, centrifugal dewatering and evaporation concentration. The actual freezing method water treatment equipment, freezing, centrifugal dehydration and evaporation concentration, has the calculated total energy consumption of 4.3+0.013+ 3.6-7.9 kwh. Compared with the theoretical energy consumption of 60kwh only by adopting the evaporation concentration treatment method, the freezing, centrifugal dehydration and evaporation concentration treatment method has very high energy consumption advantage.

4. Relationship between ice crystal size and ice crystal impurity removal rate

The relation between the size of the ice crystal and the impurity removal rate of the ice crystal needs to be researched, a large number of repeated tests are needed, the test cost of the simulated acid copper electroplating water washing wastewater is too high, the simulation acid copper electroplating water washing wastewater is toxic to human bodies, and the test is carried out by adopting a NaCl aqueous solution.

The test adopts NaCl aqueous solution 100L with concentration of about 1 percent and adopts supercooled water dynamic ice making equipmentThe ice-forming temperature is controlled to 5 temperatures from-1 ℃ to-3.5 ℃ to respectively form ice slurry, ice powder, ice flocculence, borneol and borneol, 5 kinds of ice with different shapes. In addition, a heat preservation beaker is adopted, and a progressive static freezing method is adopted to freeze 100ml of NaCl aqueous solution with the concentration of about 1 percent for 6 hours at the ambient temperature of minus 5.5 ℃ to form an integral ice block. The freezing rates of 6 kinds of ice are all 70%, and Cl in ice-melt water and raw water is measured^-A change in (c).

TABLE 5 Ice on Cl of different shapes^-Removal rate of ions

Note: raw water Cl^-The content was 5840 mg/l.

From the analysis results in Table 5, the ice powder ice, ice floc ice, small flake ice, large flake ice and the pair Cl formed by the supercooled water dynamic ice making method are shown^-The removal rate of (a) was not very different, ranging from 74.96% to 81.81%. Wherein Cl of ice floc ice^-The highest removal rate was followed by powdered ice. With the increase of the ice forming temperature, the energy consumption of ice making will increase. The larger the ice crystal particles, the slower the ice melting rate and the longer the treatment takes. The solute removing rate of ice-melting water, ice-making energy consumption and ice-melting time are comprehensively considered, and the ice forming temperature is controlled to be the optimal ice forming temperature for forming ice flocculent ice and ice powder ice. It should be particularly noted that the inventors have shown through a large number of freezing tests that powdered ice and flocculent ice are formed, and different concentrations and different ice forming temperatures for different solute compounds require actual measurement and determination for water treatment. Ice slurry ice, with the highest ice formation temperature and the smallest ice crystals formed, which should be the purest theoretically, but the results show Cl^-The removal rate is the lowest. The analysis shows that the reason is ice slurry ice, the ice crystal particles are too small, the ice-water separation is difficult, and the water content is too high. Therefore, the removal rate is higher when the supercooled water is at the temperature of minus 1.5 ℃ to minus 2.5 ℃, and the removal rate effect of ice crystals with the thickness of 0.5 mm to 1mm is higher.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention can be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. The water treatment equipment is characterized by comprising an outer barrel, an inner barrel and a driving device, wherein the inner barrel is fixedly connected into the outer barrel, the driving device is used for driving the inner barrel to rotate in the outer barrel, a plurality of dewatering holes are formed in the barrel bottom and the barrel wall of the inner barrel, filter cloth is arranged on the inner wall of the inner barrel, and a concentrated solution outlet and a fresh water outlet are formed in the bottom of the outer barrel; a feeding pipe is arranged at the upper part of the inner cylinder body; the liquid treated by the water treatment equipment is supercooled liquid.

2. The water treatment apparatus according to claim 1, wherein at least one partition plate is provided in the inner cylinder, and the partition plate is fixedly connected to the inner wall of the inner cylinder through the central axis of the inner cylinder or parallel to the central axis of the inner cylinder.

3. The water treatment apparatus as claimed in claim 2, wherein a solid sensor is disposed in the inner cylinder, the solid sensor is electrically connected to the driving device, and when ice crystals in the inner cylinder reach a predetermined height, the solid sensor controls the driving device to drive the inner cylinder to rotate by a predetermined angle; when ice crystals in each region in the inner cylinder body reach a set height, the solid inductor controls the concentrated solution outlet to be opened and controls the driving device to drive the inner cylinder body to rotate centrifugally.

4. A water treatment system, characterized by comprising the water treatment equipment of any one of claims 1 to 3 and a refrigeration system, wherein the refrigeration system is used for preparing a raw liquid into a supercooled liquid.

5. The water treatment system as claimed in claim 4, wherein the refrigeration system comprises a raw water pre-cooling regulation pool, a liquid outlet of the raw water pre-cooling regulation pool is connected with the water treatment equipment, a raw water outlet is arranged on the water treatment equipment, and the raw water outlet is sequentially connected with the evaporator and a feed pipe of the water treatment equipment through a circulating pump; the concentrated solution outlet is connected with the concentrated water tank sequentially through the first condensation tank and the raw water pre-cooling regulation tank, and the fresh water outlet is connected with the fresh water tank sequentially through the second condensation tank and the raw water pre-cooling regulation tank.

6. The water treatment system as claimed in claim 5, wherein the refrigeration system further comprises an auxiliary condenser, and the refrigerant of the auxiliary condenser flows through the throttle valve, the evaporator, the compressor, the first condensation tank and the second condensation tank in sequence through the pipeline.

7. The water treatment system as claimed in claim 6, wherein the refrigeration system further comprises a raw water heating system for heating the raw water flowing out of the water treatment apparatus before entering the circulation pump to a temperature of 0 ℃ or more.

8. The water treatment system as claimed in claim 7, wherein a raw water branch is provided on the water outlet line of the circulation pump, and the raw water branch flows through the auxiliary condenser and returns to the water inlet line of the circulation pump.

9. The water treatment system of claim 7, wherein a fresh water circulating pipe is provided at the bottom of the second condensation tank, and the fresh water circulating pipe is connected with the water distributor.

10. The water treatment system as claimed in claim 6, wherein the water inlet pipes of the first condensation tank and the second condensation tank are arranged above the highest liquid level, the water outlet pipes are arranged at the bottoms of the first condensation tank and the second condensation tank, and the top of each water outlet pipe is provided with a siphon breaking hole.