CN113461088A

CN113461088A - Natural evaporation, concentration and crystallization system and method for strong brine

Info

Publication number: CN113461088A
Application number: CN202010247056.2A
Authority: CN
Inventors: 仝胜录; 熊日华; 刘捷; 刘立国; 王海棠
Original assignee: China Energy Investment Corp Ltd; National Institute of Clean and Low Carbon Energy
Current assignee: China Energy Investment Corp Ltd; National Institute of Clean and Low Carbon Energy
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2021-10-01

Abstract

The invention relates to a natural evaporation and concentration crystallization system and method of concentrated brine, and relates to the technical field of brine treatment, and is used to solve the technical problems of slow natural evaporation and low evaporation efficiency in the prior art. The concentrated brine natural evaporation, concentration and crystallization system of the present invention includes a water supply unit and an evaporation unit. The evaporation unit includes an evaporation and concentration device and an evaporation and crystallization device. By setting the evaporation and concentration device and the evaporation and crystallization device, the concentrated brine can be concentrated and crystallized respectively. Staged treatment, so that when the concentrated brine meets the set crystallization conditions, it will be transported from the evaporation and concentration device to the evaporation and crystallization device for crystallization operation, so as to achieve the purpose of improving the evaporation speed and efficiency, which is conducive to the effective strengthening of the natural environment of the concentrated brine. evaporation.

Description

Natural evaporation, concentration and crystallization system and method for strong brine

Technical Field

The invention relates to the technical field of strong brine treatment, in particular to a system and a method for naturally evaporating, concentrating and crystallizing strong brine.

Background

The industrial wastewater zero-discharge treatment process generally comprises three steps: pretreatment, preconcentration and evaporative crystallization. The existing concentrated brine concentration and crystallization treatment generally comprises a thermal method and a natural evaporation method. Among them, the thermal process, such as chinese patent CN106422399A, discloses an energy-saving evaporation concentration crystallization system for salt solution and a control method thereof, which requires heat exchange with an external heat source to evaporate, concentrate and crystallize concentrated brine, and therefore, the energy consumption is large. Natural evaporation treatment, for example, chinese patent CN106976924A, discloses a concentrated brine zero discharge system based on atomization evaporation and a method thereof, which is to crush concentrated brine into fine particles by a certain mechanical device, thereby increasing the evaporation area of the concentrated brine by natural evaporation. However, fog drops of atomized strong brine are easy to float and blow to the outside of an evaporation pond under the condition of certain wind speed when the fog drops of the atomized strong brine are contacted with air, even formed crystal salt floats to a farther place outside the evaporation pond, the crystal salt of the strong brine contains heavy metals and other substances harmful to the environment, secondary pollution to the surrounding environment is easy to cause, and the crystallized crystal salt of the strong brine after concentration of the strong brine is easy to cause pollution, blockage and corrosion of atomization equipment, so that the system is unstable in operation and high in failure rate. Therefore, compared with the prior art, the natural evaporation has the advantage of low energy consumption, and under the guidance of the general direction of energy conservation and emission reduction called by the state, the research on how to improve the evaporation capacity and the evaporation effect of the evaporation pond is about to be the long-term development direction of the natural evaporation.

Disclosure of Invention

The invention provides a natural evaporation, concentration and crystallization system and method for strong brine, which are used for solving the technical problems of slow evaporation and low evaporation efficiency of an evaporation pond in the prior art.

According to a first aspect of the present invention, the present invention provides a concentrated brine natural evaporation concentration crystallization system, comprising:

the water supply unit is used for outputting strong brine; and

the evaporation unit is connected with the water supply unit and is used for carrying out evaporation crystallization treatment on the strong brine;

the evaporation unit includes:

the evaporation concentration device is used for receiving the strong brine output from the water supply unit and carrying out evaporation concentration treatment; and

the evaporation crystallization device is used for receiving the strong brine output by the evaporation concentration device and carrying out evaporation crystallization treatment;

wherein, the evaporation concentration device and the evaporation crystallization device are both in a modular structure;

when the strong brine in the evaporation and concentration device meets the crystallization condition, the evaporation and concentration device is communicated with the evaporation and crystallization device, so that the strong brine is conveyed to the evaporation and crystallization device from the evaporation and concentration device.

In one embodiment, the evaporative concentration apparatus comprises at least one evaporation module comprising a first circulating water tank connected to the water supply unit;

a weighing sensor is arranged in the first circulating water tank and used for measuring the real-time evaporation capacity of the evaporation module so as to obtain the concentration multiple of the concentrated brine in the evaporation module; and/or

A liquid level sensor is arranged in the first circulating water tank and used for measuring the liquid level of the first circulating water tank so as to adjust the output water quantity of the water supply unit;

wherein the crystallization condition is that the concentration multiple of the concentrated brine in the evaporation module reaches a preset upper limit of the concentration multiple;

when the strong brine of the first circulating water tank meets the water supplementing condition, the water supply unit is communicated with the evaporation concentration device, so that the strong brine is conveyed to the evaporation concentration device by the water supply unit, and the water supplementing condition is that the liquid level of the strong brine in the first circulating water tank reaches the preset liquid level lower limit.

In one embodiment, the evaporation module further comprises:

a first evaporation carrier arranged above the first circulating water tank and used for naturally evaporating the strong brine; and

the first water distribution mechanism is arranged above the first evaporation carrier and is used for distributing water to the first evaporation carrier;

the first water distribution mechanism is connected with the first circulating water tank, so that strong brine is circularly evaporated between the first circulating water tank and the first evaporation carrier.

In one embodiment, the evaporative crystallization apparatus comprises at least one crystallization module; the crystallization module comprises a second evaporation carrier and a desalting mechanism, wherein the second evaporation carrier is used for naturally evaporating and crystallizing strong brine;

and when the operation of the crystallization module meets the salt discharge condition, the desalting mechanism separates the crystallized salt separated out from the second evaporation carrier.

In one embodiment, the crystallization module further comprises:

the second water distribution mechanism is arranged above the second evaporation carrier and is used for distributing water to the second evaporation carrier; and

the second circulating water tank is arranged below the second evaporation carrier and is connected with the second water distribution mechanism, so that the concentrated brine in the second circulating water tank is circularly evaporated and crystallized between the second circulating water tank and the second evaporation carrier;

wherein, when the strong brine in the first circulating water tank meets the crystallization condition, the first circulating water tank is communicated with the second circulating water tank.

In one embodiment, the first evaporative carrier and/or the second evaporative carrier is a carrier including, but not limited to, a curtain-like carrier, a cylindrical carrier, or a strip-wadding structure.

In one embodiment, the device further comprises a post-crystallization treatment unit connected with the evaporative crystallization device, wherein the post-crystallization treatment unit is used for separating crystallized salt and mother liquor and returning the mother liquor to the evaporative crystallization device for circulation treatment.

In one embodiment, a raw water buffer tank is arranged on a pipeline between the water supply unit and the first circulating water tank; and a strong brine buffer tank is arranged on a pipeline between the first circulating water tank and the second circulating water tank.

In one embodiment, the crystallization device further comprises a flushing pipeline, wherein the flushing pipeline is used for flushing the evaporation unit and the crystallization post-treatment unit and/or separating crystallized salt precipitated in the crystallization module.

According to a second aspect of the present invention, the present invention provides a method for natural evaporation, concentration and crystallization of concentrated brine, which comprises the following steps:

step 100: judging whether the strong brine in the evaporation and concentration device meets the water supplementing condition, if so, executing a step 101; if not, executing step 102;

step 101: the water supply unit is communicated with the evaporation and concentration device, so that strong brine is conveyed to the evaporation and concentration device by the water supply unit for evaporation and concentration treatment;

step 102: the strong brine is subjected to circulating evaporation concentration treatment in the evaporation concentration device;

step 200: judging whether the strong brine in the evaporation and concentration device meets the crystallization condition, if so, executing step 201; if not, executing step 102;

step 201: the evaporation concentration device is communicated with the evaporation crystallization device, so that strong brine is conveyed to the evaporation crystallization device from the evaporation concentration device for evaporation crystallization treatment.

In one embodiment, the method further comprises the following steps:

step 300: judging whether the strong brine in the evaporation crystallization device meets the circulation condition, if so, executing the step 301;

step 301: carrying out circulating evaporation crystallization treatment on the strong brine in the evaporation crystallization device;

step 400: judging whether the operation of the evaporative crystallization device meets a salt discharge condition, if so, executing a step 401; if not, go to step 301;

step 401: separating the crystallized salt from the evaporative crystallization device into a post-crystallization treatment unit;

step 500: and the crystallization post-treatment unit is used for dehydrating and collecting the crystallized salt.

Compared with the prior art, the invention has the advantages that: through setting up evaporation concentration device and evaporation crystallization device, can carry out the segmentation processing of concentration and crystallization operation respectively to the strong brine, make the strong brine when satisfying the crystallization condition of settlement, just can carry out the crystallization operation to the evaporation crystallization device in by the evaporation concentration device to reach the purpose that improves evaporation rate and efficiency, be favorable to the effective intensive natural evaporation of strong brine.

Drawings

The invention will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a concentrated brine natural evaporation concentration crystallization system (a post-crystallization treatment unit is not shown in the figure) according to an embodiment of the present invention.

FIG. 2 is a schematic connection diagram of a concentrated brine natural evaporation concentration crystallization system in an embodiment of the present invention;

FIG. 3a is a front view of an evaporation module in one embodiment of the invention;

FIG. 3b is a left side view of the evaporation module shown in FIG. 3 a;

FIG. 3c is a top view of the evaporation module shown in FIG. 3 a;

FIG. 3d is an expanded schematic view of the first evaporation carrier in the evaporation module shown in FIG. 3 a;

FIG. 4a is a front view of an evaporation module in another embodiment of the invention;

FIG. 4b is a top view of the evaporation module shown in FIG. 4 a;

FIG. 5a is a front view of an evaporation module in another embodiment of the invention;

FIG. 5b is a top view of the evaporation module shown in FIG. 5 a;

FIG. 6 is a front view of a crystallization module in an embodiment of the present invention;

FIG. 7 is a flow chart of natural evaporation concentration crystallization in the example of the present invention.

Reference numerals:

100-a water supply unit; 101-a water source; 102-a water replenishing pump; 103-raw water buffer tank; 104-raw water pump;

200-an evaporation unit; 210-an evaporative concentration unit; 220-evaporative crystallization device; 230-a crystal water replenishing pump; 240-strong brine buffer tank;

211-an evaporation module; 212-a first circulation water tank; 213-a first evaporative carrier; 214-a first water distribution mechanism; 2141-a water collecting pipe; 2142-water distribution pipes;

2131-fixing the shaft by evaporation carrier; 2132-a tightening mechanism; 213 a-curtain evaporation support; 2133-perforated area;

213 b-a cylindrical evaporative carrier; 2134-fixing plate;

213 c-evaporation support in rope form; 2135-upper fixing plate; 2136-lower fixing plate;

221-a crystallization module; 222-a second circulating water tank; 223-a second evaporative carrier; 224-a second water distribution mechanism; 225-a discharge valve; 226-crystallization circulation pump;

300-post crystallization treatment unit; 310-salt slurry dewaterer; 320-a screw conveyor; 330-salt bin.

Detailed Description

The invention will be further explained with reference to the drawings.

As shown in fig. 1 and 2, according to a first aspect of the present invention, the present invention provides a concentrated brine natural evaporation concentration crystallization system, which comprises a water supply unit 100, an evaporation unit 200 and a post-crystallization treatment unit 300 connected in sequence, and further comprises a flushing pipeline for flushing the evaporation unit 100 and the post-crystallization treatment unit 300 and/or separating crystallized salt precipitated in a crystallization module.

The natural evaporation, concentration and crystallization system for the strong brine is different from other evaporation and concentration devices utilizing hot steam, and the purpose of concentrating the strong brine is achieved by fully utilizing wind energy and solar energy; and it does not need external heat source, only needs the power output of strong brine circulation, therefore the running cost is greatly reduced.

In addition, the natural evaporation, concentration and crystallization system for strong brine also comprises a control unit which is electrically connected with various devices such as valves, pumps and the like which are described below so as to realize automatic control.

The evaporation unit 200 is used for carrying out evaporation crystallization treatment on the concentrated brine. Specifically, the evaporation unit 200 includes an evaporation concentration device 210 and an evaporation crystallization device 220. The evaporation concentration device 210 is used for receiving the strong brine output from the water supply unit 100 and performing evaporation concentration treatment; the evaporation crystallization device 220 is used for receiving the concentrated brine output from the evaporation concentration device 210 and performing evaporation crystallization treatment.

Through setting up evaporation concentration device 210, evaporation crystallization device 220 and crystallization after-treatment unit 300, can carry out the segmentation processing of concentration, crystallization and salt operation respectively to the strong brine to reach the purpose of more effectively strengthening the natural evaporation effect.

Each unit of the present invention will be described in detail below.

The water supply unit 100 is used for outputting a concentrated brine raw material and comprises a water source 101 and a raw water buffer tank 103, wherein the water source 101 is connected with the raw water buffer tank 103, and a raw water pump 104 is arranged on a pipeline connected with the water source 101 and the raw water buffer tank 103 and used for providing power for the concentrated brine flowing into the raw water buffer tank 103.

Under the action of the raw water pump 104, the strong brine in the water source 101 enters the raw water buffer tank 103 through a pipeline and a valve. The raw water buffer tank 103 is connected with the evaporation unit 200, a water replenishing pump 102 and a control valve are arranged on a pipeline connected with the raw water buffer tank 103 and the evaporation unit 200, and the water replenishing pump 102 is used for providing power for the concentrated brine flowing into the evaporation unit 200.

The raw water buffer tank 103 may be provided with a weight sensor and/or a liquid level sensor connected to the control unit, and the control unit monitors the amount of the concentrated brine in the raw water buffer tank 103 according to data collected by the weight sensor and/or the liquid level sensor. If the quantity of the concentrated brine in the raw water buffer tank 103 is insufficient, the control unit controls the raw water pump 104 to be started, so that the concentrated brine is supplied to the raw water buffer tank 103, and the raw water buffer tank 103 is automatically replenished with water to ensure normal water supply of the system. If the amount of the concentrated brine in the raw water buffer tank 103 is sufficient, the control unit controls the water replenishing pump 102 to input the concentrated brine into the evaporation unit 200.

The evaporation unit 200 further comprises a crystal water replenishing pump 230, a concentrated brine buffer tank 240 and a control valve which are arranged on a pipeline connecting the evaporation concentration device 210 and the evaporation crystallization device 220. The crystal water replenishing pump 230 is used for pumping the concentrated brine in the evaporation and concentration device 210 to the evaporation and crystallization device 220.

The concentrated brine buffer tank 240 is used for protecting the evaporative crystallization device 220 at the downstream of the evaporative concentration device 210, and the impact on the evaporative crystallization device is avoided, so that the stable operation of the system is not influenced. Specifically, the strong brine in the evaporation concentration device 210 may be first transferred to the strong brine buffer 240, and the strong brine in the strong brine buffer 240 is pumped to the evaporation crystallization device 220 by the crystallization water replenishing pump 230, so as to maintain the stability of the system.

Wherein, the evaporation concentration device 210 and/or the evaporation crystallization device 220 are of modular structure. The modular construction facilitates the installation and transport of the system, wherein each module has a certain evaporation area, so that the number and connection mode of each module can be selected according to the evaporation load of the concentrated brine. In addition, the requirements of different evaporation capacities can be met by arranging a plurality of modules to operate simultaneously.

As one example of the modular structure, the evaporation concentration apparatus 210 includes at least one evaporation module 211, and the number and connection manner of the evaporation modules 211 may be set as required. In the embodiment shown in fig. 2, 1-3 parallel evaporation modules 211 may be provided. Each evaporation module 211 can also be deployed and stacked up and down according to the field wind direction and installation conditions.

The evaporation module 211 is explained in detail below. The evaporation module 211 includes a first circulation water tank 212 connected to the water supply unit 100, a first evaporation carrier 213, and a first water distribution mechanism 214. In addition, the evaporation module 211 further includes a first module body (or module frame) for supporting, and the first water distribution mechanism 214 is connected to the first module body. An evaporation curtain type evaporation carrier lower platform is arranged below the first module body, and a salt water separation effect can be achieved if the crystallized salt falls down.

The first water distribution mechanism 214 is disposed above the first evaporation carrier 213 and is used for distributing water uniformly into the first evaporation carrier 213.

Preferably, the first water distribution mechanism 214 includes a water collection pipe 2141 and a water distribution pipe 2142 connected to the water collection pipe 2141. The water collecting pipes 2141 are main pipes, the water distributing pipes 2142 are branch pipes, and the strong brine is distributed in each water distributing pipe 2142 through the water collecting pipes 2141.

Each water distribution pipe 2142 contacts the first evaporation carrier 213 to distribute water into the first evaporation carrier 213. The portion of the water distribution pipe 2142 contacting the first evaporation carrier 213 is provided with holes and/or grooves at equal intervals to maintain the first evaporation carrier 213 in a state of being wetted and having water flow all the time.

The water collecting pipe 2141 of the first water distributing mechanism 214 is connected to the first water circulating tank 212, and a concentration circulating pump 215 and a control valve are disposed on a pipeline connecting the two. The first circulation water tank 212 is disposed below the first evaporation carrier 213, the concentrated brine on the first evaporation carrier 213 may be returned to the first circulation water tank 212, and the concentrated brine may be circulated between the first circulation water tank 212 and the first evaporation carrier 213 to be evaporated in a reduced amount by the concentration circulation pump 215.

The first circulating water tank 212 is also connected with the raw water buffer tank 103, and the control unit can control the water replenishing pump 102 to input the concentrated brine in the raw water buffer tank 103 into the first circulating water tank 212.

A sensor is provided in the evaporation module 211. The sensor can be a weighing sensor and/or a liquid level sensor, and can also be a conductivity sensor, a density sensor (densimeter) and the like, so that the aim of accurately controlling the flow rate and the flow direction of the concentrated brine is fulfilled.

Specifically, a load cell and/or a level sensor may be provided in the first circulation water tank 212. Wherein, weighing sensor is used for measuring the real-time evaporation capacity of evaporation module 211 to obtain the concentration multiple of concentrated brine in the evaporation module. Furthermore, the operating frequency of the concentration circulating pump 215 and ultimately the circulating water flow rate can be adjusted based on the real-time evaporation measured by the load cell.

The weighing sensor can carry out data acquisition and comparison to the business turn over water volume of each evaporation module 211, can set up the lower limit value and/or the upper limit value of strong brine concentration multiple according to concentrated ratio and total intake weight and real-time weight ratio from this.

The liquid level sensor is used to measure the liquid level of the first circulating water tank 212 to adjust the output water amount of the water supply unit 100.

The concentrated brine is evaporated and concentrated in the evaporation and concentration device 210, and when the concentrated brine in the evaporation and concentration device 210 meets the water supplementing condition, the water supply unit 100 is communicated with the evaporation and concentration device 210, so that the concentrated brine is conveyed to the evaporation and concentration device 210 from the water supply unit 100.

Specifically, the water replenishing condition is that the level of the concentrated brine in the first circulating water tank 212 reaches a preset lower level limit. In other words, if the level of the concentrated brine in the first circulating water tank 212 is low, the control unit controls the make-up water pump 102 to input the concentrated brine in the raw water buffer tank 103 into the first circulating water tank 212.

When the concentrated brine in the evaporation concentration device 210 meets the crystallization condition, the evaporation concentration device 210 is communicated with the evaporation crystallization device 220, so that the concentrated brine is conveyed from the evaporation concentration device 210 to the evaporation crystallization device 220.

Specifically, the crystallization condition is that the concentration multiple of the concentrated brine in the evaporation module 211 reaches a preset upper limit of the concentration multiple. In other words, if the concentration ratio of the concentrated brine in the first circulating water tank 212 is large enough, that is, if there is a crystal salt to be precipitated, the evaporation and concentration device 210 is communicated with the evaporation and crystallization device 220, the control unit can control the crystal water replenishing pump 230 to input the concentrated brine in the first circulating water tank 212 to the evaporation and crystallization device 220.

Furthermore, the crystallization conditions may also be such that the conductivity of the concentrated brine in the evaporation module 211 reaches a preset upper limit.

It should be noted that the concentration factor is determined by calculating the ratio of the total water inlet weight to the weight of the concentrated brine in the first circulating water tank 212 by a weighing sensor.

Because the concentration times of different concentrated brine components reaching crystallization are different, a preset upper limit of the concentration times is set according to the water quality characteristics.

The first evaporation carrier 213 may have various forms and structures, and may be a carrier including, but not limited to, a curtain-like carrier, a cylindrical carrier, or a strip-wadding structure. The first evaporation carrier 213 increases the evaporation area by uniformly distributing the concentrated brine thereon, thereby achieving an arrangement of as reasonable and as many evaporation areas as possible in a limited space. Compared with the evaporation of the water surface of the evaporation pond, the evaporation area of the pond surface can be more than 100 times through the first evaporation carrier 213.

When the first evaporation carrier 213 is used as a carrier to perform secondary distribution evaporation on the strong brine, the strong brine does not leak outside.

In some embodiments of the present invention, the first evaporation carrier 213 is a curtain evaporation carrier 213 a. As shown in fig. 3a, 3b, 3c and 3d, the curtain-type evaporation carrier 213a may be a cloth curtain, for example, a cloth with acid resistance, alkali resistance and certain hydrophilicity may be used. The upper end of the curtain type evaporation carrier 213a is a cloth hanging region for contacting with the water distribution pipe 2142, and the lower end thereof is fixed and wound on the evaporation carrier fixing shaft 2131. Further, the curtain evaporation carrier 213a is provided with a tightening mechanism 2132 which can prevent the curtain evaporation carrier 213a from shaking due to an excessive wind load.

The curtain evaporation carrier 213a is further provided with an opening 2133, which is a region of the curtain evaporation carrier 213a through which the concentrated brine flows. The holes in the perforated area 2133 may be vertical holes, which can keep the wind flow field of the evaporation module 211 clear and the evaporation saturated steam drift.

Further, the size and arrangement of the holes in the perforated area 2133 may be determined by the field climate conditions and wind direction, or may be staggered by simulation calculations.

In some embodiments of the present invention, as shown in fig. 4a and 4b, the first evaporation carrier 213 is a cylindrical evaporation carrier 213 b. The cylindrical evaporation carrier 213b can adapt to the enhanced evaporation in any wind direction, and is more suitable for outdoor wind direction unstable areas. The cylindrical evaporation carrier 213b may be a cloth tube.

Specifically, the fixing plate 2134 is disposed at the upper end of the cylindrical evaporation carrier 213b, the fixing plate 2134 is connected to the first water distribution mechanism 214, and the first water distribution mechanism 214 makes the concentrated brine slowly wet along the cylindrical evaporation carrier 213b and flow into the first circulation water tank 212, so as to increase the evaporation area and enhance the evaporation.

In some embodiments of the present invention, as shown in fig. 5a and 5b, the first evaporation carrier 213 is a rope-type evaporation carrier 213c, which is woven by the same material to form a rope-like structure with a certain thickness, so that a larger evaporation area can be realized in a certain space. The concentrated brine can flow down through the rope-shaped evaporation carrier 213c and complete evaporation concentration on the surface of the rope body.

Similarly, upper and lower ends of the string-type evaporation carriers 213c may be provided with upper and

lower fixing plates

2135 and 2136 to fix the string-type evaporation carriers 213 c.

In addition, the evaporative concentration unit 210 includes an on-line brine salinity monitoring device to monitor the salinity of the brine on the lines between the various components of the evaporative concentration unit 210.

As one example of a modular structure, the evaporative crystallization apparatus 220 includes at least one crystallization module 221. The crystallization module 221 includes a second circulation water tank 222, a second evaporation carrier 223, a second water distribution mechanism 224, and a desalination mechanism. In addition, the crystallization module 221 further includes a second module body (or a second module frame) for supporting, and the second water distribution mechanism 224 is connected to the second module body.

The second water distribution mechanism 224 is disposed above the second evaporation carrier 223 to distribute water uniformly to the second evaporation carrier 223, and the structure form thereof may be similar to the first water distribution mechanism 214, which is not described again in the present invention.

The second water distribution mechanism 224 is connected with the second circulating water tank 222, and a crystallization circulating pump 226 and a control valve are arranged on a pipeline connected with the second water distribution mechanism and the second circulating water tank. The second circulation water tank 222 is disposed under the second evaporation carrier 223, the concentrated brine on the second evaporation carrier 223 may be refluxed into the second circulation water tank 222, and the concentrated brine may be circulated between the second circulation water tank 222 and the second evaporation carrier 223 to be evaporated and crystallized by the crystallization circulation pump 226.

When the concentrated brine circulates and evaporates and crystallizes between the second circulating water tank 222 and the second evaporation carrier 223, the liquid level information of the concentrated brine in the second circulating water tank 222 is obtained through the liquid level sensor in the second circulating water tank 222. If the level of the concentrated brine in the second circulating water tank 222 is lower than the predetermined value, it indicates that the concentrated brine in the second circulating water tank 222 cannot maintain the normal circulating crystallization, and therefore the control unit controls the crystallization circulating pump 226 to stop, so that the concentrated brine in the crystallization module 221 is not circulated any more. After the liquid level of the concentrated brine in the second circulating water tank 222 reaches a normal level, the control unit controls the crystallization circulating pump 226 to start to continue circulating the concentrated brine.

The second circulation water tank 222 is connected to the first circulation water tank 212 through a pipe and selectively communicates with the pipe therebetween. A control valve is provided in a pipe between them, and when the concentrated brine in the first circulation water tank 212 satisfies the crystallization condition, the control valve is opened to communicate the second circulation water tank 222 with the first circulation water tank 212. In addition, a crystal water replenishing pump 230 is provided on a pipe connecting the second circulation water tank 222 and the first circulation water tank 212 to supply power. When the strong brine in the first circulating water tank 212 meets the crystallization condition, the control valve is opened, the control unit controls the concentration circulating pump 215 to convey the strong brine in the first circulating water tank 212 to the strong brine buffer tank 240, and controls the crystallization water replenishing pump 230 to convey the strong brine in the strong brine buffer tank 240 to the second circulating water tank 222.

Preferably, the second circulation water tank 222 has a tapered structure with a large top and a small bottom, which facilitates the collection of crystallized salt.

Further, a circulation pump interface is arranged on the second circulation water tank 222 to prevent the crystallization salt from blocking the crystallization circulation pump 226, which is beneficial to the concentrated crystallization of the concentrated brine on the second circulation water tank 222 and between the second evaporation carrier 223. The crystallized salt is precipitated on the second circulating water tank 222 and the second evaporation carrier 223. The crystallized salt is deposited on the bottom of the second circulating water tank 222, and when the crystallized salt is accumulated to a certain degree, the desalting operation can be started by a timing program.

The second evaporation carrier 223 is used to evaporate and crystallize the concentrated brine naturally, and may have different structures (e.g., hydrophobic materials) according to different characteristics of the crystallized salt formed by the concentrated brine, or may have the same or similar structure as the first evaporation carrier 213, which is not described in detail herein.

The first evaporation carriers 213 and the second evaporation carriers 223 may be provided in plural sets, and the intervals between the first evaporation carriers 213 and the intervals between the second evaporation carriers 223 may be provided to be equal. Different optimal intervals can be set according to different meteorological conditions, and the number and the intervals of the first evaporation carriers 213 and the second evaporation carriers 223 can be changed by changing the number of the water distribution pipes.

The first evaporation carrier 213 and the second evaporation carrier 223 can both pass through an automatic wind alignment program and mechanism, so that the first evaporation carrier 213 and the second evaporation carrier 223 can be automatically rotated and adjusted to always keep the windward direction, namely, the maximum evaporation amount is always kept to operate. For this, curtain water guide grooves may be formed at the bottoms of the first evaporation carrier 213 and the second evaporation carrier 223 so that the concentrated brine is collected and introduced into the water guide grooves and then enters the first circulation water tank 212 and the second circulation water tank 222, and thus, how the first evaporation carrier 213 and the second evaporation carrier 223 rotate, the concentrated brine is introduced into the corresponding circulation water tanks.

If the operation time is long, the salt deposition on the first evaporation carrier 213 and the second evaporation carrier 223 may affect the evaporation effect thereof, so that the evaporation carrier regeneration may be realized by adjusting the water distribution flow rate to flush the first evaporation carrier 213 and the second evaporation carrier 223.

The desalting mechanism is connected to the second evaporation carrier 223, for example, the second evaporation carrier 223 may be disposed on the second evaporation carrier 223, and the desalting mechanism is used to separate the crystallized salt precipitated on the second evaporation carrier 223 from the second evaporation carrier 223. Wherein the salt removing mechanism can be separated by means of rapping or scraping.

By way of example, as shown in fig. 6, a front reel 2231 and a rear reel 2232 may be provided on the front and rear sides of the second evaporation support 223, respectively, and a salt scraping device 2233 may be provided near the front reel 2231 and the rear reel 2232, respectively. When the crystallization module 221 is operated to satisfy the salt discharging condition, the front and rear ends of the second evaporation carrier 223 are rewound by the front reel 2231 and the rear reel 2232 in two directions, and the second evaporation carrier 223 is scraped by the salt scraping device 2233 during the rewinding process. The scraped-off crystallized salt is collected in the second circulation water tank 222 and discharged from the bottom thereof through the discharge valve 225.

If the crystallized salt precipitated from the strong brine is hard and not easy to scrape, the strong brine can be used to flush the second evaporation carrier 223 through the flushing pipeline, so as to form a crystal slurry mixture in the second circulating water tank 222, and the crystal slurry is pumped to the post-crystallization treatment unit for treatment.

Wherein, the salt discharging condition is that the preset running time is reached, namely, the desalting operation is started at regular time.

The post-crystallization treatment unit 300 is used for separating the crystallized salt and the mother liquor and returning the mother liquor to the evaporative crystallization device for recycling treatment. The post-crystallization treatment unit 300 includes a salt slurry dehydrator 310, a screw conveyor 320, and a salt bin 330. The salt slurry dehydrator 310 is connected to the bottom of the second circulating water tank 222, and the crystal slurry collected in the second circulating water tank 222 enters the salt slurry dehydrator 310 to perform solid-liquid separation.

The liquid output end of the salt slurry dehydrator 310 is connected with the second circulating water tank 222 so as to return the mother liquor to the second circulating water tank 222 for cyclic evaporation and crystallization; the solid output end of the salt slurry dehydrator 310 is connected with the screw conveyer 320, and the crystallized salt is conveyed to the salt bin 330 by the screw conveyer 320 to be collected all together.

The salt slurry dehydrator 310 may be a centrifugal dehydrator.

After the evaporation concentration, the evaporation crystallization and the salt discharging operation are finished, the washing can be carried out through the washing pipeline, so that the regeneration of the cloth is facilitated and the blockage of the crystallization pipeline is prevented.

The effect of the present invention will be described below by taking the first evaporation carrier 213 shown in FIG. 3a as an example.

The first evaporation carrier 213 is a curtain evaporation carrier 213a, and basic parameters of the curtain evaporation carrier 213a are as follows.

The specification of the curtain evaporation carriers 213a is 2000mm x 1600mm, the number of the curtain evaporation carriers 213a is 36 groups, the distance between the adjacent curtain evaporation carriers 213a is 50m, and the evaporation area of the curtain evaporation carriers 213a is 115m²。

The curtain evaporation carrier 213a is suspended above the first circulation water tank 212, and the flexible connection structure is adopted between the first circulation water tank 212 and the curtain evaporation carrier 213a and between the water distribution pipe 2142 and the first module body, so that the whole weighing is convenient.

In addition, because the evaporation capacity needs to be quantized, the lower end of the first module body is provided with the mounting base plate, and the on-site leveling mounting is facilitated.

The embodiment of the present invention was conducted by using the above-mentioned evaporation and concentration apparatus 210. The experiments were divided into 6 groups, and the experimental conditions for each group are shown in table 1. The evaporation amount per floor area and the evaporation intensity per floor area of the evaporation concentration apparatus 210 obtained in the 6 sets of experiments are shown in table 2 for 24 hours.

In order to illustrate the technical effect of the invention, the invention is provided with a comparative example, and the comparative example is also 6 groups. Each pair of ratios has the same experimental conditions as the corresponding examples. Comparative example water surface evaporation was used to calculate the evaporation intensity. Specifically, a water tank having a certain area may be provided on an electronic balance and the evaporation amount per unit area for 24 hours may be calculated.

Table 1 below shows a list of experimental environments.

Table 1 list of experimental conditions

Table 2 below is a table showing evaporation intensities obtained in examples and comparative examples.

TABLE 2 comparative table of examples and comparative examples

As can be seen from Table 2, the evaporation intensity per unit area of the evaporation and concentration apparatus 210 of the present invention is about 20 times that of the water surface evaporation under the same meteorological conditions. It can be demonstrated that the efficiency of the evaporative concentration apparatus 210 of the present invention can be improved by about 20 times compared to the evaporation of the water surface of the evaporation pond.

Further, the results of comparing the present invention with mechanical atomization evaporation are shown in Table 3.

It should be noted that the mechanical atomization and evaporation is implemented by adopting the technical scheme disclosed in the concentrated brine zero-emission system and method thereof based on atomization and evaporation in the chinese patent (CN 106976924A).

TABLE 3 comparison list of the present invention and Chinese patent CN106976924A

As can be seen from Table 3, the present invention has many advantages over the mechanical atomization evaporation method in the prior art.

In some embodiments, the concentrated brine natural evaporation concentration crystallization system of the present invention can also utilize industrial waste heat or hot air to increase the temperature of the concentrated brine, thereby increasing the evaporation efficiency of the evaporation concentration device 210. In this case, the number of the evaporation modules 211 can be reduced under the same load condition, thereby reducing the cost.

In some embodiments, the concentrated brine natural evaporation concentration crystallization system can also enhance the evaporation effect by combining the solar energy optimization process.

In some embodiments, the concentrated brine natural evaporation, concentration and crystallization system of the present invention has an external heat source and energy, such as an additional concentrated brine evaporation and condensed water recovery device.

The existing concentrated brine zero-emission system and method based on atomization and evaporation, namely the technical scheme disclosed in Chinese patent CN106976924A, increases the contact area of concentrated brine with air and solar radiation by atomizing and spraying the concentrated brine in an evaporation pond, and further plays a role in enhancing evaporation, but concentrated brine droplets can drift to the surrounding environment of the evaporation pond along with the change of wind speed and wind direction, and crystallized salt formed after the concentrated brine is volatilized easily causes secondary pollution to the surrounding environment and villages.

Compared with the Chinese patent CN106976924A, firstly, the invention distributes the strong brine on the first evaporation carrier 213 and the second evaporation carrier 223 with certain areas, and uses the evaporation cloth as the carrier to carry out secondary distribution evaporation on the strong brine, so that the strong brine does not leak outside, the formed crystal salt can realize the separation of the brine, and the crystal salt does not cause secondary pollution to the surroundings.

Secondly, the invention can realize the automatic variable load operation of the device according to the climate conditions, and the operation load can be changed by the real-time evaporation capacity because of the arrangement of sensors such as a weighing sensor, a liquid level sensor and the like.

Thirdly, the transmission structure of the invention is simple, the operation cost is low, and the failure rate is low.

Fourthly, the concentrated brine concentration and the concentrated brine crystallization of the present invention are respectively implemented in the evaporation concentration device 210 and the evaporation crystallization device 220, and both adopt a modular structure, each module is arranged with a certain evaporation area according to transportation and field conditions, and a plurality of modules are assembled for operation according to evaporation load, thereby facilitating transportation and uniform installation.

Fifthly, the evaporation module 211 and the crystallization module 221 of the invention adopt different structures, and the crystallization module 221 is provided with a carrier surface desalting mechanism besides the evaporation area and the arrangement of the carrier, thereby facilitating the collection of the crystallization salt precipitated from the saturated strong brine.

Sixthly, weighing sensors are arranged in the first circulating water tank 212 and the second circulating water tank 222, so that the concentration multiple and the evaporation weight can be monitored, and the control unit can control the pumps in each unit to adjust the adjustment of the pumps, so that the operation frequency of the pumps can be adjusted according to the evaporation amount.

Seventh, the corresponding valves are actuated according to the evaporation capacity and concentration ratio of the brine or the salinity and density of the brine (the sensor type is determined according to the specific quality characteristics of the brine), so that the brine enters the second circulating water tank 222 from the first circulating water tank 212 to be concentrated to obtain salt.

In conclusion, the concentrated brine natural evaporation, concentration and crystallization system is suitable for concentrated brine crystallization treatment of a high-salt and high-organic matter treatment process at the tail end of the existing wastewater treatment process and an evaporation pond treatment process. The natural evaporation concentration crystallization system of the strong brine is different from a thermal evaporation crystallization process, realizes evaporation concentration and crystallization of the strong brine by utilizing solar energy and wind energy to naturally evaporate, and strengthens natural evaporation by enlarging evaporation area, so that an external heating source is not needed, energy consumption is only limited to material conveying and circulating water distribution of a pump to an evaporation carrier, and the operation cost is low.

The concentrated brine natural evaporation, concentration and crystallization system is different from the conventional thermal evaporation and crystallization device, and does not need high temperature and high pressure conditions during implementation, so that the first evaporation carrier 213 and the second evaporation carrier 223 can be made of industrial hydrophilic cloth which is resistant to acid, alkali, weather (such as terylene) and light, the first module body forming the evaporation module 211 and the second module body forming the crystallization module 221 can be made of common carbon steel and an anticorrosive coating, and the direct contact water part is made of 316L or other anticorrosive materials, so that the concentrated brine natural evaporation, concentration and crystallization system is lower in material cost compared with titanium alloy and dual-phase steel used in thermal evaporation and crystallization.

As mentioned above, in the present invention, the weighing sensor is used to balance the incoming and outgoing materials in each unit, and for different concentrated brines, the parameters of "concentration multiple" of each unit are used to realize evaporation and crystallization of the concentrated brines, and the concentrated brines reaching a limit value are discharged to the evaporation and crystallization device 220.

Therefore, the brine natural evaporation concentration crystallization system is different from a membrane method concentration technology, and does not have the risk of membrane fouling and blocking and the risk of corrosion of parts in thermal method equipment, so that the brine natural evaporation concentration crystallization system has wide applicable range of the quality of the brine, and the natural evaporation can be realized as long as the brine can be conveyed to an evaporation carrier. Therefore, the invention can also be applied to the strong brine zero-discharge process in different industries or other fields of seawater airing and evaporation, and the function of airing and salting concentrated water can be realized through an improved scheme.

In addition, the invention has the additional effect that the ambient atmospheric humidity can be increased in the natural evaporation process, thereby improving the local small-environment ecology.

According to a second aspect of the present invention, as shown in fig. 7, the present invention provides a method for naturally evaporating, concentrating and crystallizing a strong brine, which can use the above system for naturally evaporating, concentrating and crystallizing a strong brine to treat the strong brine. Specifically, the method of the present invention comprises the steps of:

the program is initialized and each unit performs self-checking.

First, step 10 is performed.

Step 10: judging whether the liquid level of the strong brine in the raw water buffer tank 103 is lower than a preset liquid level lower limit, if so, executing the step 11; if not, go to step 100.

Step 11: the control unit controls the raw water pump 104 to start up, so that the concentrated brine is supplied to the raw water buffer tank 103.

Specifically, the liquid level information of the concentrated brine is obtained through a liquid level sensor in the raw water buffer tank 103, and if the concentrated brine is insufficient, the control unit controls the raw water pump 104 to start, so that the concentrated brine is supplied to the raw water buffer tank 103; if the raw water buffer tank 103 contains sufficient brine, the raw water buffer tank may be supplied with the brine in the evaporation and concentration device 210.

Next, step 100 is performed.

Step 100: judging whether the strong brine in the evaporation concentration device 210 meets the water supplementing condition, if so, executing the step 101; if not, go to step 102.

Step 101: the water supply unit 100 is communicated with the evaporation and concentration device 210, so that the strong brine is conveyed to the evaporation and concentration device 210 from the water supply unit 100 for evaporation and concentration treatment; step 102: the concentrated brine is subjected to cyclic evaporation concentration in the evaporation concentration device 210.

Specifically, the liquid level information is acquired by a liquid level sensor in the evaporation module 211 located in the first circulation water tank 212. If the liquid level in the first circulating water tank 212 reaches the preset liquid level lower limit, the control unit controls the water replenishing pump 102 to input the concentrated brine in the raw water buffer tank 103 into the first circulating water tank 212, so that the concentrated brine can be subjected to circulating evaporation concentration treatment in the evaporation concentration device 210; if the liquid level in the first circulation water tank 212 does not reach the preset lower liquid level limit, it means that the concentrated brine in the first circulation water tank 212 can maintain a normal circulation level, and thus the concentrated brine circulates between the first circulation water tank 212 and the first evaporation carrier 213 to be evaporated and concentrated.

Subsequently, step 200 is performed.

Step 200: judging whether the strong brine in the evaporation and concentration device 210 meets the crystallization condition, if yes, executing step 201; if not, go to step 102.

Step 201: the evaporation concentration device is communicated with the evaporation crystallization device, so that the strong brine is conveyed to the evaporation crystallization device from the evaporation concentration device for evaporation crystallization treatment.

Specifically, the real-time evaporation amount is obtained through a weighing sensor in the evaporation module 211, which is located in the first circulating water tank 212, and the concentration multiple of the concentrated brine in the first circulating water tank 212 is obtained according to calculation, and if the concentration multiple reaches a preset upper limit of the concentration multiple, the control unit controls the crystal water-replenishing pump 230 to input the concentrated brine in the first circulating water tank 212 into the second circulating water tank 222 of the evaporation crystallization device 220; if the concentration ratio does not reach the upper limit of the preset concentration ratio, the concentrated brine in the first circulating water tank 212 continuously circulates between the first circulating water tank 212 and the first evaporation carrier 213, so as to increase the concentration ratio.

Then, step 300 is performed.

Step 300: and (4) judging whether the strong brine in the evaporation crystallization device 220 meets the circulation condition, if so, executing the step 301.

Step 301: the concentrated brine is subjected to cyclic evaporation crystallization treatment in the evaporation crystallization device 220.

Specifically, the level information of the concentrated brine in the second circulating water tank 222 is obtained by a level sensor provided in the second circulating water tank 222 in the evaporative crystallization device 220. If the liquid level of the brine in the second circulation water tank 222 is lower than the predetermined value, that is, the circulation condition is not satisfied, it indicates that the brine in the second circulation water tank 222 cannot maintain normal circulation crystallization, so the control unit controls the crystallization circulation pump 226 to stop, so that the brine in the crystallization module 221 is not circulated any more, and at this time, the brine is only input into the second circulation water tank 222 from the first circulation water tank 212. After the liquid level of the concentrated brine in the second circulating water tank 222 reaches the normal level, that is, the circulating condition is satisfied, the control unit controls the crystallization circulating pump 226 to start to continue circulating the concentrated brine.

Step 400 is then performed.

Step 400: judging whether the operation of the evaporative crystallization device 220 meets a salt discharge condition, if so, executing a step 401; if not, go to step 301.

Step 401: the crystallized salt in the evaporative crystallization device 220 is separated therefrom into the post-crystallization treatment unit 300.

Specifically, the operation time of the evaporative crystallization device 220 is obtained by the control unit, and if the operation time reaches a preset time length, it indicates that the salt discharge condition is satisfied, so the control unit controls the desalting mechanism 225 to perform the desalting operation. The front and rear ends of the second evaporation carrier 223 are rewound by the front and

rear reels

2231 and 2232 of the second evaporation carrier 223 in both directions of the front and rear sides, and the second evaporation carrier 223 is scraped off by the salt scraping device 2233 during the rewinding process. The scraped-off crystallized salt is collected in the second circulation water tank 222 and discharged from the bottom thereof through the discharge valve 225. If the salt-yielding condition is not satisfied, the concentrated brine needs to be continuously subjected to the cyclic evaporation crystallization treatment in the evaporation crystallization device 220.

Finally, step 500 is performed.

Step 500: the post-crystallization treatment unit 300 performs dehydration and collection treatment on the crystallized salt. The crystallized salt is collected into the salt bin 330 and collected all together by separating the crystallized salt from the mother liquor and returning the mother liquor to the second circulation water tank 222 for circulation treatment.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A concentrated crystallization system of nature evaporation of strong brine, characterized by, includes:

the water supply unit is used for outputting strong brine; and

the evaporation unit includes:

the evaporation crystallization device is used for receiving the strong brine output by the evaporation concentration device and carrying out evaporation crystallization treatment; wherein, the evaporation concentration device and the evaporation crystallization device are both in a modular structure; when the strong brine in the evaporation and concentration device meets the crystallization condition, the evaporation and concentration device is communicated with the evaporation and crystallization device, so that the strong brine is conveyed to the evaporation and crystallization device from the evaporation and concentration device.

2. The system for natural evaporation, concentration and crystallization of concentrated brine according to claim 1, wherein the evaporation and concentration device comprises at least one evaporation module, and the evaporation module comprises a first circulating water tank connected with the water supply unit;

3. The strong brine natural evaporation concentration crystallization system according to claim 2, wherein the evaporation module further comprises:

4. The concentrated brine natural evaporation concentration crystallization system according to claim 3, wherein the evaporation crystallization device comprises at least one crystallization module; the crystallization module comprises a second evaporation carrier and a desalting mechanism, wherein the second evaporation carrier is used for naturally evaporating and crystallizing strong brine;

5. The strong brine natural evaporation concentration crystallization system according to claim 4, wherein the crystallization module further comprises:

6. The system for natural evaporation, concentration and crystallization of concentrated brine according to claim 4 or 5, wherein the first evaporation carrier and/or the second evaporation carrier is a carrier including but not limited to curtain-like carrier, cylindrical carrier or strip-wadding structure.

7. The system for natural evaporation, concentration and crystallization of concentrated brine according to claim 4 or 5, characterized by further comprising a post-crystallization treatment unit connected with the evaporation crystallization device, wherein the post-crystallization treatment unit is used for separating crystallized salt and mother liquor and returning the mother liquor to the evaporation crystallization device for recycling treatment.

8. The system for naturally evaporating, concentrating and crystallizing concentrated brine according to claim 5, wherein a raw water buffer tank is arranged on a pipeline between the water supply unit and the first circulating water tank; and a strong brine buffer tank is arranged on a pipeline between the first circulating water tank and the second circulating water tank.

9. The system for naturally evaporating, concentrating and crystallizing concentrated brine according to claim 7, further comprising a flushing pipeline, wherein the flushing pipeline is used for flushing the evaporation unit and the post-crystallization treatment unit and/or separating crystallized salt precipitated in the crystallization module.

10. A method for naturally evaporating, concentrating and crystallizing strong brine is characterized by comprising the following steps:

11. The system for natural evaporation, concentration and crystallization of concentrated brine according to claim 10, further comprising the steps of: