CN112875966A - Energy-saving saline-alkali water multistage freezing desalination device and process - Google Patents
Energy-saving saline-alkali water multistage freezing desalination device and process Download PDFInfo
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 355
- 230000008014 freezing Effects 0.000 title claims abstract description 147
- 238000007710 freezing Methods 0.000 title claims abstract description 147
- 239000003513 alkali Substances 0.000 title claims abstract description 83
- 238000010612 desalination reaction Methods 0.000 title claims abstract description 40
- 238000000034 method Methods 0.000 title claims abstract description 15
- 239000013505 freshwater Substances 0.000 claims abstract description 88
- 239000011780 sodium chloride Substances 0.000 claims abstract description 28
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims abstract description 27
- 238000004062 sedimentation Methods 0.000 claims abstract description 25
- 239000012267 brine Substances 0.000 claims description 41
- 150000003839 salts Chemical class 0.000 claims description 41
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 claims description 41
- 230000005484 gravity Effects 0.000 claims description 26
- 238000011033 desalting Methods 0.000 claims description 22
- 239000013078 crystal Substances 0.000 claims description 17
- 238000007790 scraping Methods 0.000 claims description 13
- 238000001914 filtration Methods 0.000 claims description 11
- 238000001035 drying Methods 0.000 claims description 9
- 238000001816 cooling Methods 0.000 claims description 6
- 239000012535 impurity Substances 0.000 claims description 5
- 239000003507 refrigerant Substances 0.000 claims description 5
- 241000894006 Bacteria Species 0.000 claims description 3
- 239000011859 microparticle Substances 0.000 claims description 3
- 238000002425 crystallisation Methods 0.000 claims description 2
- 230000008025 crystallization Effects 0.000 claims description 2
- 239000007921 spray Substances 0.000 claims 1
- 238000005057 refrigeration Methods 0.000 abstract description 20
- 238000000746 purification Methods 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 7
- 239000003595 mist Substances 0.000 description 7
- 238000004519 manufacturing process Methods 0.000 description 4
- DTGKSKDOIYIVQL-WEDXCCLWSA-N (+)-borneol Chemical compound C1C[C@@]2(C)[C@@H](O)C[C@@H]1C2(C)C DTGKSKDOIYIVQL-WEDXCCLWSA-N 0.000 description 3
- REPVLJRCJUVQFA-UHFFFAOYSA-N (-)-isopinocampheol Natural products C1C(O)C(C)C2C(C)(C)C1C2 REPVLJRCJUVQFA-UHFFFAOYSA-N 0.000 description 3
- 229940116229 borneol Drugs 0.000 description 3
- CKDOCTFBFTVPSN-UHFFFAOYSA-N borneol Natural products C1CC2(C)C(C)CC1C2(C)C CKDOCTFBFTVPSN-UHFFFAOYSA-N 0.000 description 3
- DTGKSKDOIYIVQL-UHFFFAOYSA-N dl-isoborneol Natural products C1CC2(C)C(O)CC1C2(C)C DTGKSKDOIYIVQL-UHFFFAOYSA-N 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000008235 industrial water Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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Classifications
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F9/00—Multistage treatment of water, waste water or sewage
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/001—Processes for the treatment of water whereby the filtration technique is of importance
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/22—Treatment of water, waste water, or sewage by freezing
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F2001/007—Processes including a sedimentation step
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
- Y02A20/124—Water desalination
Abstract
The invention relates to an energy-saving saline-alkali water multistage freezing desalination device and a process, which comprises a pretreatment system and a freezing system, wherein saline-alkali water is treated by the pretreatment system and then is cooled and desalinated in the freezing system, and the energy-saving saline-alkali water multistage freezing desalination device is characterized in that: the pretreatment system comprises a reservoir, a high-density sedimentation tank, a V-shaped filter tank and a multi-media filter, wherein the reservoir is connected with a water inlet of the high-density sedimentation tank through a pipeline, a water outlet of the high-density sedimentation tank is connected with a water inlet of the V-shaped filter tank through a pipeline, a water outlet of the V-shaped filter tank is connected with a water inlet of the multi-media filter tank through a pipeline, and a water outlet of the multi-media filter tank is connected with the refrigeration system through a pipeline; the invention realizes the purification process of the saline water without pollution in the whole process, is safe and environment-friendly, has high working efficiency, greatly relieves the pressure of shortage of fresh water resources and provides guarantee for the life of people.
Description
Technical Field
The invention relates to a saline-alkali water desalting device, in particular to an energy-saving saline-alkali water multistage freezing desalting device and process.
Background
Fresh water resources are in shortage day by day, but saline-alkali water resources are abundant. The water used in daily agriculture, industrial water and domestic water can not be separated from fresh water, and water shortage brought by population growth is caused, so that a fresh water source of natural resources can not meet the requirements of current life, but saline-alkali water resources in the natural resources are rich, and a saline-alkali water desalting device is urgently needed for desalting the saline-alkali water for people to use. In order to solve the problem caused by the shortage of fresh water resources, the development and utilization of saline-alkali water resources are bound to be put forward in the future.
Disclosure of Invention
The invention provides an energy-saving saline water multistage freezing and desalting device and process in order to overcome the defects of the technical problems.
The invention relates to an energy-saving saline water multistage freezing desalination device and a process, which are characterized in that: the saline-alkali water multistage freezing desalination device comprises a pretreatment system and a freezing system, the saline-alkali water is treated by the pretreatment system and then is cooled and desalinated in the freezing system, the pretreatment system comprises a reservoir, a high-density sedimentation tank, a V-shaped filter tank and a multi-media filter, the reservoir is connected with a water inlet of the high-density sedimentation tank through a pipeline, a water outlet of the high-density sedimentation tank is connected with a water inlet of the V-shaped filter tank through a pipeline, a water outlet of the V-shaped filter tank is connected with a water inlet of the multi-media filter through a pipeline, and a water outlet of the multi-media filter is connected with the freezing system through a pipeline;
the freezing system comprises a primary freezing treatment device, a primary fresh water tank, a secondary freezing treatment device, a secondary fresh water tank and a high-grade brine tank, wherein a water inlet of the primary freezing treatment device is connected with a water outlet of the multi-media filter through a pipeline, a water outlet of the primary freezing treatment device is connected with a water inlet of the primary fresh water tank through a pipeline, a water outlet of the primary fresh water tank is connected with a water inlet of the secondary freezing treatment device through a pipeline, a water outlet of the secondary freezing treatment device is connected with a water inlet of the secondary fresh water tank through a pipeline, and concentrated saline-alkali water outlets are arranged at the lower ends of the primary freezing treatment device and the secondary freezing treatment device and are connected with the;
the first-stage freezing treatment device is provided with a multi-stage freezing treatment structure, the freezing treatment structures of each stage are connected in parallel to form the first-stage freezing treatment device, the front side of each stage of freezing treatment structure is connected with a cold encountering device, the freezing treatment structure comprises a booster pump, a water inlet valve, a rotary type freezing desalter, a gravity desalting tank and a concentrated brine outlet valve, a water inlet pipe of the cold encountering device is connected with a water inlet main pipe of the first-stage freezing treatment device, a water outlet pipe of the cold encountering device is respectively connected with a water inlet of the booster pump of the freezing treatment structure of each stage through a pipeline, a water outlet of the booster pump is connected with a water inlet of the water inlet valve through a pipeline, a water outlet of the water inlet valve is connected with a water inlet of the rotary type freezing desalter through a pipeline, an outlet of the rotary type freezing desalter is connected with a water inlet of the gravity desalting, the water outlet of the gravity desalting tank is connected with the water inlet of the primary fresh water tank through a pipeline, and the lower end of the rotary type freezing desalter is provided with a concentrated saline-alkali water outlet which is connected with the high-grade brine tank through a pipeline;
a plurality of rotary type freezing desalinization devices are arranged on the freezing treatment structure of each stage and connected in parallel, a water inlet of each rotary type freezing desalinization device is connected with a water outlet of a water inlet valve through a pipeline, and a concentrated saline-alkali water outlet of each rotary type freezing desalinization device is connected with a high-grade brine pool through a pipeline;
the rotary type freezing desalter is provided with an outer barrel and a refrigerating rotor, a cavity for freezing and separating cold water is formed between the refrigerating rotor and the outer barrel, the middle part of the left side in the cavity is provided with a water inlet lowest water level sensor, the middle upper part of the left side in the cavity is provided with a water inlet highest water level sensor, and the bottom in the cavity is provided with a salinity sensor and a water outlet level sensor for sensing the salinity and alkalinity of concentrated saline-alkali water after desalting; an opening for ice crystals to flow out is formed in the right side of the outer barrel, an ice scraping knife is arranged in the middle of the right side of the refrigerating rotor, one end of the ice scraping knife is connected with the refrigerating rotor and used for scraping ice crystals condensed on the refrigerating rotor, and the other end of the ice scraping knife penetrates through the opening in the right side of the outer barrel and extends into the gravity salt supporting water tank;
the structure of the second-stage freezing treatment device is the same as that of the first-stage freezing treatment device, the first-stage fresh water in the first-stage fresh water tank is set as the inlet water of the second-stage freezing treatment device, the second-stage fresh water desalted by the second-stage freezing treatment device flows into the second-stage fresh water tank, and the residual concentrated saline-alkali water desalted by the second-stage freezing treatment device flows into the high-grade saline-alkali water tank;
the front end of the water inlet of the high-grade brine pool is provided with a pressure water pump, the water inlet of the inner side of the high-grade brine pool is provided with an atomizing nozzle, the right upper end of the high-grade brine pool is provided with a condenser pipe for cooling low-salt water mist into water, the lower end of the condenser pipe is provided with a fresh water receiving disc for receiving fresh water, the bottom of the high-grade brine pool is provided with a high-salt water receiving disc for receiving high-salt water mist, the side surface of the bottom of the high-grade brine pool is provided with a high-salt water outlet, and the lower end of the high-salt water outlet of;
the multistage freezing desalination process of the saline-alkali water is realized by the following steps:
a) primary filtration of raw water; raw water flows into a high-density sedimentation tank from a reservoir, suspended matters, temporary hardness, alkalinity and chromaticity in the raw water are removed in the high-density sedimentation tank, the raw water flows into a V-shaped filter tank after being filtered by the high-density sedimentation tank, part of the suspended matters which are not completely treated in the raw water due to the high-density sedimentation tank are removed in the V-shaped filter tank, the raw water treated by the V-shaped filter tank flows to a multi-medium filter, the suspended matters, colloidal impurities, micro-particles and bacteria in the raw water are removed in the multi-medium filter to form primary filtered saline-alkali water, and the salt content of the primary filtered saline-alkali water after primary filtration is controlled to be less than 8 g/L;
b) first-stage freezing treatment; feeding the prefiltered saline water obtained in the step a) into a primary freezing treatment device for filtering, firstly, feeding the prefiltered saline water into a precooling device for precooling to 0 ℃, opening a water inlet valve, feeding the prefiltered saline water into a rotary type freezing desalter for desalting under the action of a pressure pump, feeding a refrigerant into a rotor to form a refrigerating rotor, wherein the refrigerating rotor is in a set freezing temperature range; along with the rotation of the refrigerating rotor, the primary filtered saline water meets cold and freezes ice, ice crystals are attached to the refrigerating rotor, the thickness of an ice layer is gradually increased, ice crystals attached to the refrigerating rotor are stripped by an ice scraper and enter a gravity brackish water pool to carry out gravity bracketing, the ice pieces are melted to form primary fresh water, the primary fresh water is gathered and enters the primary fresh water pool, and the primary fresh water is used as raw water of a secondary freezing treatment device to carry out secondary desalination;
after the primarily filtered saline-alkali water is desalinated, the average salt content of the primary fresh water in the primary fresh water tank is 3g/l, when the salt content of the concentrated saline-alkali water reaches 9.14g/l, the threshold value of the primary concentrated water is reached, a concentrated saline-alkali water outlet valve of the primary freezing treatment device is automatically opened to discharge water, and the concentrated saline-alkali water is introduced into a high-grade saline-alkali water tank;
c) second-stage freezing treatment; the first-level fresh water enters a second-level freezing treatment device for filtering: the first-stage fresh water enters a second-stage freezing treatment device for desalination, after desalination, the average salt content of the second-stage fresh water in a second-stage fresh water tank is 2g/l, when the salt content of concentrated saline-alkali water reaches 8.43g/l, the threshold value of the second-stage concentrated water is reached, a concentrated saline-alkali water outlet valve of the second-stage freezing treatment device is automatically opened, and the concentrated saline-alkali water flows into a high-grade saline water tank;
d) desalting concentrated saline-alkali water in a high-grade saline-alkali pond: the concentrated saline-alkali water is cooled and atomized in the high-grade saline-alkali water tank to separate fresh water, the high-salinity saline-alkali water finally enters a drying yard for drying and crystallization to form salt crystal grains, and the desalination of the saline-alkali raw water is finished.
The invention has the beneficial effects that: the energy-saving multistage freezing desalination device and process for saline-alkali water realize primary filtration of the saline-alkali water and remove impurities such as suspended matters in raw water by arranging the preposed reservoir, the high-density sedimentation tank, the V-shaped filter tank and the multi-medium filter. Through setting up the one-level refrigeration processing apparatus and the second grade refrigeration processing apparatus of the same structure, realized the automatic filtration and the purification of saline and alkaline water, obtained fresh water and concentrated high salt solution. The fresh water yield is determined by the relationship between the freezing rate and the contact area (prefiltered brine-alkali water and low-temperature rotor). And determining the water inflow and the threshold value of the concentrated brine according to the requirements of the desalination rate and the salinity of the fresh water. Through setting up the high salt water pond, realized the ultimate filtration and the purification of high concentration saltwater alkaline, the whole process realizes the saltwater alkaline purification process of zero pollution, and safety ring protects, and work efficiency is high, has greatly alleviated the pressure of fresh water resource shortage, provides the guarantee for people's life.
Drawings
FIG. 1 is a schematic diagram of the desalination flow structure of the energy-saving saline-alkali water multistage freezing desalination device and process of the invention;
FIG. 2 is a schematic structural view of a primary refrigeration treatment apparatus and a secondary refrigeration treatment apparatus according to the present invention;
FIG. 3 is a cross-sectional view of the present invention taken along line A-A of FIG. 2;
FIG. 4 is a schematic diagram of a rotary desalination unit according to the present invention;
fig. 5 is a diagram of the energy conversion of the present invention.
In the figure: 1, a water storage tank, 2 high-density sedimentation tanks, 3V type filter tanks, 4 multi-medium filters, 5 primary refrigeration treatment devices, 6 primary fresh water tanks, 7 secondary refrigeration treatment devices, 8 secondary fresh water tanks and 9 high-grade brine tanks;
the system comprises a 501 chilling device, a 502 booster pump, a 503 water inlet valve, a 504 rotary type freezing desalter, an 505 ice scraping knife, a 506 gravity desalination water pool, a 507 concentrated brine outlet valve, a 508 salinity sensor, a 509 water outlet level sensor, a 510 condenser pipe, a 511 refrigeration rotor, a 512 outer cylinder, a 513 drying yard, a 514 atomization nozzle, a 515 high brine receiving disc, a 516 water inlet highest level sensor, a 517 water inlet lowest level sensor, a 518 fresh water receiving disc and a 519 booster pump.
Detailed Description
The invention is further described with reference to the following figures and examples.
As shown in FIG. 1, the schematic diagram of the desalination flow structure of the energy-saving multistage freezing desalination device and process of saline water of the invention is provided, fig. 2 and fig. 3 show the overall structure schematic diagrams of the primary and secondary freezing treatment devices of the invention, and the energy-saving saline-alkali water multistage freezing desalination device and process comprises a pretreatment system and a freezing system, wherein the saline-alkali water is treated by the pretreatment system and then is cooled and desalinated in the freezing system, the pretreatment system comprises a water storage tank 1, a high-density sedimentation tank 2, a V-shaped filter tank 3 and a multi-media filter 4, the water storage tank 1 is connected with a water inlet of the high-density sedimentation tank 2 through a pipeline, a water outlet of the high-density sedimentation tank 2 is connected with a water inlet of the V-shaped filter tank 3 through a pipeline, a water outlet of the V-shaped filter tank 3 is connected with a water inlet of the multi-media filter 4 through a pipeline, and a water outlet of the multi-media filter 4 is connected with.
The high-density sedimentation tank 2 removes suspended matters, temporary hardness, alkalinity and chroma in raw water, the v-shaped filter tank 3 removes part of the suspended matters which are not processed and cleaned by the high-density sedimentation tank in the raw water, the multi-media filter 4 removes the suspended matters or colloidal impurities in the raw water, particularly micro particles, bacteria and the like which cannot be removed by a sedimentation technology can be effectively removed, BOD5, COD and the like have a certain removal effect, and primary filtered saline water (saline water after removing the impurities) is formed.
The freezing system includes one-level freezing treatment device 5, one-level fresh water tank 6, second grade freezing treatment device 7, second grade fresh water tank 8 and senior salt water tank 9, the water inlet of one-level freezing treatment device 5 is connected through the pipeline with the delivery port of multi-media filter 4, the delivery port of one-level freezing treatment device 5 is connected through the pipeline with the water inlet of one-level fresh water tank 6, the delivery port of one-level fresh water tank 6 is connected through the pipeline with the water inlet of second grade freezing treatment device 7, the delivery port of second grade freezing treatment device 7 is connected through the pipeline with the water inlet of second grade fresh water tank 8, one-level freezing treatment device 5 all is provided with concentrated saline and alkaline water export and all is connected with senior salt water tank 9 with the lower extreme.
The first-stage freezing treatment device 5 is provided with a multi-stage freezing treatment structure, the freezing treatment structures of each stage are connected in parallel to form the first-stage freezing treatment device 5, the front side of each stage of freezing treatment structure is connected with a cold encountering device 501, the freezing treatment structure comprises a booster pump 502, a water inlet valve 503, a rotary freezing desalter 504, a gravity desalting tank 506 and a concentrated brine outlet valve 507, the water inlet pipe of the cold encountering device 501 is connected with the water inlet header pipe of the first-stage freezing treatment device 5, the water outlet pipe of the cold encountering device 501 is respectively connected with the water inlet of the booster pump 502 of the freezing treatment structure of each stage through a pipeline, the water outlet of the booster pump 502 is connected with the water inlet of the water inlet valve 503 through a pipeline, the water outlet of the water inlet valve 503 is connected with the water inlet of the freezing rotary desalting device 504 through a pipeline, the outlet of, the concentrated brine outlet valve 507 is arranged on a connecting pipeline between the rotary type freezing desalter 504 and the gravity desalination tank 506, the water outlet of the gravity desalination tank 506 is connected with the water inlet of the first-level fresh water tank 6 through a pipeline, and the lower end of the rotary type freezing desalter 504 is provided with a concentrated brine outlet and is connected with the high-level brine tank 9 through a pipeline.
The freezing treatment structure of each stage is provided with a plurality of rotary type freezing desalinization devices 504 which are connected in parallel, the water inlet of each rotary type freezing desalinization device 504 is connected with the water outlet of the water inlet valve 503 through a pipeline, and the concentrated saline-alkali water outlet of each rotary type freezing desalinization device 504 is connected with the high-grade saline pool 9 through a pipeline.
As shown in fig. 4, a schematic structural diagram of the rotary type desalination device of the present invention is shown, the rotary type desalination device 504 is provided with an outer cylinder 512 and a refrigeration rotor 511, a cavity for separating cold water from ice is formed between the refrigeration rotor 511 and the outer cylinder 512, a lowest water inlet level sensor 517 is disposed in the middle of the left side of the cavity, a highest water inlet level sensor 516 is disposed in the middle upper portion of the left side of the cavity, and a salinity sensor 508 and a water outlet level sensor 509 are disposed at the bottom of the cavity for sensing the salinity and alkalinity of the desalinated concentrated saline-alkali water; an opening for ice crystals to flow out is formed in the right side of the outer barrel 512, an ice scraping blade 505 is arranged in the middle of the right side of the refrigerating rotor 511, one end of the ice scraping blade 505 is connected with the refrigerating rotor 511 and used for scraping ice crystals condensed on the refrigerating rotor 511, and the other end of the ice scraping blade penetrates through the opening in the right side of the outer barrel 512 and extends into the gravity brine pool 506.
The structure of the second-stage freezing treatment device 7 is the same as that of the first-stage freezing treatment device 5, the first-stage fresh water in the first-stage fresh water tank 6 is set as the inlet water of the second-stage freezing treatment device 7, the second-stage fresh water desalted by the second-stage freezing treatment device 7 flows into the second-stage fresh water tank 8, and the residual concentrated saline-alkali water desalted by the second-stage freezing treatment device 7 flows into the high-grade saline-alkali tank 9.
The primary filtered saline-alkali water is cooled to 0 ℃ through the precooling device 501, enters a cavity between the outer barrel 512 and the refrigerating rotor 511, a refrigerant is introduced into the rotor to form the refrigerating rotor 511, and the refrigerating rotor 511 is within a designed freezing temperature range. Along with the rotation of the refrigerating rotor 511, the primary filtered saline water meets cold and freezes ice, the thickness of the ice layer is gradually increased, the ice scraper 505 peels off the ice crystals attached to the refrigerating rotor 511, the ice crystals enter the gravity desalting water pool 506 for gravity desalination, the ice crystals are melted to form primary fresh water, the primary fresh water is collected and enters the primary fresh water pool 6, and the primary fresh water is used as raw water for secondary desalination of the secondary freezing treatment device 7. The highest water inlet level sensor 516 and the lowest water inlet level sensor 517 are disposed in the cavity between the outer cylinder 512 and the cooling rotor 511, and when the water amount reaches the lowest water level, the water inlet valve 503 is automatically opened to replenish the water amount in time.
The salinity sensor 508 detects the salinity of the residual saline-alkali water in the cavity, when the salinity reaches a concentrated water threshold, the concentrated saline water outlet valve 507 is automatically opened to discharge the concentrated saline water in time, when the discharged water reaches a set water level, the water outlet level sensor 509 senses that the water level reaches the lowest water level, and the water inlet valve 503 is automatically opened to replenish the water in time.
The front end of the water inlet of the high-grade brine pool 9 is provided with a pressurizing water pump 519, the water inlet of the inner side of the high-grade brine pool 9 is provided with an atomizing nozzle 514, the right upper end of the high-grade brine pool 9 is provided with a condenser pipe 510 for cooling low-salt water mist into water, the lower end of the condenser pipe 510 is provided with a fresh water receiving disc 518 for receiving fresh water, the bottom of the high-grade brine pool 9 is provided with a high-salt water receiving disc 515 for receiving high-salt water mist, the side face of the bottom of the high-grade brine pool 9 is provided with a high-salt water outlet, and the lower end of the high-salt water outlet of the outer.
The fresh water flow path of the invention is that the primary filtered saline-alkali water enters the precooling device 501 for precooling to 0 ℃, the water inlet valve 503 is opened to make the primary filtered saline-alkali water fill the cavity between the outer cylinder 512 and the refrigerating rotor 511, the refrigerant is introduced into the rotor to form the refrigerating rotor 511, and the refrigerating rotor 511 is in the designed freezing temperature range; with the rotation of the refrigerating rotor 511, the primarily filtered saline-alkali water is frozen when meeting cold, the thickness of the ice layer is gradually increased, the ice scraper 505 peels off the ice crystals attached to the refrigerating rotor 511, the ice crystals enter the gravity desalting water tank 506 for gravity desalination, the ice flakes are melted to form primary fresh water, the primary fresh water is gathered and enters the primary fresh water tank 6, and the primary fresh water is used as the raw water of the secondary refrigerating device 7 for secondary desalination.
High brine flow path: fresh water ice is gradually separated out, the salinity of residual saline-alkali water in the cavity between the outer barrel 512 and the refrigerating rotor 511 is gradually increased, and when the salinity reaches the primary concentrated water threshold value (detected by the salinity sensor 508), the concentrated saline-alkali water outlet valve 507 is automatically opened to discharge residual liquid in the cavity. The operation flow of the secondary refrigeration device 7 is the same as above. The concentrated water is pressurized by a pressurizing water pump 519, and forms water mist under the action of the atomizing nozzles 514, and the low-salinity water mist is condensed by the top condensing pipe 510 to form fresh water which falls into a fresh water receiving tray 518. The high salt water mist falls into the high salt water receiving tray 515, flows to the high salt water outlet, and enters the drying yard 513 for drying.
As shown in FIG. 5, which shows the energy conversion diagram of the present invention, the pre-filtered saline-alkali water is cooled to 0 ℃ by the pre-cooling device 501, and the heat is released for melting the borneol in the gravity dehydration pool 506 and increasing the temperature of the high-saline water. The refrigerant flowing out of the refrigeration rotor 511 passes through the heat exchange channel in the gravity desalting water tank 506 to exchange heat with the ice to be melted, and then is cooled to-15 ℃ by the air cooler, and enters the low-temperature rotor to continue working.
The method comprises the following steps of:
primary concentrated water threshold determination:
the primary freezing desalination rate is 65%, the salt content of the primary filtered saline-alkali water is 8g/l, and the salt content of the primary fresh water is less than or equal to 3 g/l. Finally, the salt content of the fresh water is less than or equal to 2g/l.
The average salt content of the first-level fresh water is 3g/l, and the average salt content of the inlet water is 8.57 g/l; the lowest salt content of the inlet water is 8g/l, and the lowest salt content of the outlet water is 2.8 g/l; the highest salt content of the effluent water quality is 3.2g/l, and the highest salt content of the influent water quality is 9.14 g/l. When the salt content of the concentrated brine is 9.14g/l, the first-stage concentrated water threshold value is reached, and the concentrated water outlet valve is automatically opened.
Determining the water inflow of the primary refrigeration system:
salt balance: 8.57V2'+3V1'＝8V
Volume balance: v is V1+V2＝V1'+V2'
V2＝V1'
V1'＝at
Wherein V1Is the initial water quantity m in a single rotary drum3，V2Is the water inflow m3，V1' is the fresh water yield m3，V2' is the water yield m of the concentrated brine3And V is the total volume m3A is ice production rate m3H, t is water inlet time m3。
V1＝28π×300×10＝0.26m3；V2＝0.0296m3；V1'＝0.0296m3；V2'＝0.26m3；
a＝(0.3121×28π×28π+9.6)×(300÷28π)＝0.082m3/h
t＝0.0296÷0.082＝0.36h
The water inflow in the cavity of the outer cylinder and the low-temperature rotor is 0.0296m within 0.36h3Total water amount of 0.2896m3. The water inflow of the first-stage refrigeration system is 965.3m all day3。
And (3) determining a secondary concentrated water threshold:
the primary freezing desalination rate is 65 percent, the salt content of the initial saline-alkali water (the lowest salt content of the inlet water quality) is 3g/l, and the salt content of the final outlet water quality is less than or equal to 2g/l.
The average salt content of the effluent water quality of the second-stage fresh water pool is 2g/l, and the average salt content of the influent water is 5.7 g/l; the lowest salt content of inlet water is 3g/l, and the lowest salt content of outlet water is 1.05 g/l; the highest salt content of the outlet water is 2.95g/l, and the highest salt content of the inlet water is 8.43 g/l. When the salt content of the concentrated brine is 8.43g/l, the secondary concentrated water threshold is reached, and the concentrated water outlet valve is automatically opened.
Determining the water inflow of the secondary refrigeration system:
salt balance: 5.7V2'+2V1'＝3V
Volume balance: v is V1+V2＝V1'+V2'
V2＝V1'
V1'＝at
Wherein V1Is the initial water quantity m in a single rotary drum3，V2For feeding waterQuantity m3，V1' is the fresh water yield m3，V2' is the water yield m of the concentrated brine3And V is the total volume m3A is ice production rate m3H, t is water inlet time m3。
V1＝28π×300×10＝0.26m3；V2＝0.702m3；V1'＝0.702m3；V2'＝0.26m3；
a＝(0.3121×28π×28π+9.6)×(300÷28π)＝0.082m3/h
t＝0.702÷0.082＝8.56h
The water inflow in the cavity of the outer cylinder and the low-temperature rotor within 8.56h is 0.702m3Total water amount of 0.962m3. The water inflow of the first-stage refrigeration system is 134.86m all day3。
The total annual water inflow of the refrigeration system.
965.3×365＝3.5×105m3
And (5) analyzing the water yield.
Y＝0.3121X+9.6
Wherein Y is the contact area cm of the precooled saline-alkali water and the inner cylinder2And Y is the ice production rate ml/h, the diameter of the metal inner cylinder is designed to be 50cm, and the length is designed to be 300 cm. The clearance between the inner cylinder and the outer cylinder is 10 cm. The primary refrigeration system employed 60 drums. The secondary refrigeration system employed 43 drums.
Water production per hour per unit:
Y＝0.3121X+9.6＝(0.3121×28π×28π+9.6)×(300÷28π)＝0.082m3/h
single one day water yield: 0.082 × 24 ═ 1.97m3/h
The water inflow per hour of a single metal rotary drum of the secondary refrigeration system is as follows: 0.962 ÷ 8.56 ═ 0.112m3/h
Determining the number of the secondary drums: 0.082 × 60 ÷ 0.112 ═ 43 radicals
Total water yield per day: 1.97X 43 ═ 84.71m3
Annual water yield: 84.71X 365 ═ 3.09 ten thousand m3
And (6) energy analysis.
Q＝cmΔt
Q is the absorbed or released heat J, c is the specific heat J/kg of the substance, m is the mass kg of the object, and delta t is the temperature change deg.C.
The operation condition is selected in the Aksu area of Xinjiang, taking the summer condition as an example, the average temperature is 31 ℃ in 8 months in summer and the average temperature of farmland drainage is 27 ℃.
The energy generated in the pre-cooling process of the pretreated saline-alkali water is 1.09 multiplied by 1011J
M＝ρv＝103×965.3＝9.65×105kg
M is mass kg, rho is density kg/M2。
Q＝cmΔt＝4.2×103×9.65×105×(27-0)＝1.09×1011J
When the borneol in the first-stage gravity desalting water tank is melted, the total heat absorption is 2.89 multiplied by 1011J。
V＝1.97×60＝118.2m3
M＝ρv＝0.9×103×118.2＝1.06×105kg
Q＝cmΔt＝2.1×103×1.06×105×(-13-0)＝-2.89×109J
When the borneol in the secondary gravity desalting water tank is melted, the total heat absorption is 2.08 multiplied by 109J。
V＝1.97×43＝84.71m3
M＝ρv＝0.9×103×84.71＝7.62×104kg
Q＝cmΔt＝2.1×103×7.62×104×(-13-0)＝-2.08×109J。
Claims (1)
1. An energy-saving saline-alkali water multistage freezing desalination device and a process thereof are characterized in that: the saline-alkali water multistage freezing desalination device comprises a pretreatment system and a freezing system, the saline-alkali water is treated by the pretreatment system and then is cooled and desalinated in the freezing system, the pretreatment system comprises a reservoir (1), a high-density sedimentation tank (2), a V-shaped filter tank (3) and a multi-media filter (4), the reservoir (1) is connected with a water inlet of the high-density sedimentation tank (2) through a pipeline, a water outlet of the high-density sedimentation tank (2) is connected with a water inlet of the V-shaped filter tank (3) through a pipeline, a water outlet of the V-shaped filter tank (3) is connected with a water inlet of the multi-media filter (4) through a pipeline, and a water outlet of the multi-media filter (4) is connected with the freezing system through a pipeline;
the freezing system comprises a primary freezing treatment device (5), a primary fresh water tank (6), a secondary freezing treatment device (7), a secondary fresh water tank (8) and a high-grade brine tank (9), wherein a water inlet of the primary freezing treatment device (5) is connected with a water outlet of the multi-media filter (4) through a pipeline, a water outlet of the primary freezing treatment device (5) is connected with a water inlet of the primary fresh water tank (6) through a pipeline, a water outlet of the primary fresh water tank (6) is connected with a water inlet of the secondary freezing treatment device (7) through a pipeline, a water outlet of the secondary freezing treatment device (7) is connected with a water inlet of the secondary fresh water tank (8) through a pipeline, and concentrated saline-alkali water outlets are arranged at the lower ends of the primary freezing treatment device (5) and the secondary freezing treatment device (7) and are connected with the high-grade;
the first-stage freezing treatment device (5) is provided with a multi-stage freezing treatment structure, each stage of freezing treatment structure is connected in parallel to form the first-stage freezing treatment device (5), the front side of each stage of freezing treatment structure is connected with a cold encountering device (501), the freezing treatment structure comprises a booster pump (502), a water inlet valve (503), a rotary type freezing desalter (504), a gravity desalting tank (506) and a concentrated brine outlet valve (507), the water inlet pipe of the cold encountering device (501) is connected with the water inlet header pipe of the first-stage freezing treatment device (5), the water outlet pipe of the cold encountering device (501) is respectively connected with the water inlet of the booster pump (502) of the freezing treatment structure of each stage through a pipeline, the water outlet of the booster pump (502) is connected with the water inlet of the water inlet valve (503) through a pipeline, the water outlet of the water inlet valve (503) is connected with the, the outlet of the rotary type freezing desalter (504) is connected with the water inlet of the gravity desalination pool (506) through a pipeline, a concentrated saline water outlet valve (507) is arranged on a connecting pipeline between the rotary type freezing desalter (504) and the gravity desalination pool (506), the water outlet of the gravity desalination pool (506) is connected with the water inlet of the primary fresh water pool (6) through a pipeline, the lower end of the rotary type freezing desalter (504) is provided with a concentrated saline water outlet which is connected with the high-grade saline water pool (9) through a pipeline;
a plurality of rotary type freezing desalinization devices (504) are arranged on the freezing treatment structure of each stage and connected in parallel, the water inlet of each rotary type freezing desalinization device (504) is connected with the water outlet of the water inlet valve (503) through a pipeline, and the concentrated saline-alkali water outlet of each rotary type freezing desalinization device (504) is connected with the high-grade saline pool (9) through a pipeline;
an outer cylinder (512) and a refrigerating rotor (511) are arranged on the rotary type freezing desalter (504), a cavity for freezing and separating cold water is formed between the refrigerating rotor (511) and the outer cylinder (512), a lowest water inlet level sensor (517) is arranged in the middle of the left side in the cavity, a highest water inlet level sensor (516) is arranged at the middle upper part of the left side in the cavity, and a salinity sensor (508) and a water outlet level sensor (509) for sensing the salinity and alkalinity of concentrated saline-alkali water after desalting are arranged at the bottom in the cavity; an opening for ice crystals to flow out is formed in the right side of the outer barrel (512), an ice scraping knife (505) is arranged in the middle of the right side of the refrigerating rotor (511), one end of the ice scraping knife (505) is connected with the refrigerating rotor (511) and used for scraping ice crystals condensed on the refrigerating rotor (511), and the other end of the ice scraping knife penetrates through the opening in the right side of the outer barrel (512) and extends into the gravity brine supporting pool (506);
the structure of the secondary freezing treatment device (7) is the same as that of the primary freezing treatment device (5), primary fresh water in the primary fresh water tank (6) is set as inlet water of the secondary freezing treatment device (7), the secondary fresh water desalted by the secondary freezing treatment device (7) flows into the secondary fresh water tank (8), and the residual concentrated saline-alkali water desalted by the secondary freezing treatment device (7) flows into the high-grade saline water tank (9);
a pressurizing water pump (519) is arranged at the front end of a water inlet of the high-grade brine tank (9), an atomizing spray head (514) is arranged at a water inlet on the inner side of the high-grade brine tank (9), a condensing pipe (510) for cooling low-salt brine fog into water is arranged at the right upper end of the high-grade brine tank (9), a fresh water receiving disc (518) for receiving fresh water is arranged at the lower end of the condensing pipe (510), a high-salt brine receiving disc (515) for receiving high-salt brine fog is arranged at the bottom of the high-grade brine tank (9), a high-salt brine outlet is formed in the side surface of the bottom of the high-grade brine tank (9), and a drying field (513) for drying the high-salt brine is arranged at;
the multistage freezing desalination process of the saline-alkali water is realized by the following steps:
a) primary filtration of raw water; raw water flows into a high-density sedimentation tank from a reservoir, suspended matters, temporary hardness, alkalinity and chromaticity in the raw water are removed in the high-density sedimentation tank, the raw water flows into a V-shaped filter tank after being filtered by the high-density sedimentation tank, part of the suspended matters which are not completely treated in the raw water due to the high-density sedimentation tank are removed in the V-shaped filter tank, the raw water treated by the V-shaped filter tank flows to a multi-medium filter, the suspended matters, colloidal impurities, micro-particles and bacteria in the raw water are removed in the multi-medium filter to form primary filtered saline-alkali water, and the salt content of the primary filtered saline-alkali water after primary filtration is controlled to be less than 8 g/L;
b) first-stage freezing treatment; feeding the prefiltered saline water obtained in the step a) into a primary freezing treatment device for filtering, firstly, feeding the prefiltered saline water into a precooling device for precooling to 0 ℃, opening a water inlet valve, feeding the prefiltered saline water into a rotary type freezing desalter for desalting under the action of a pressure pump, feeding a refrigerant into a rotor to form a refrigerating rotor, wherein the refrigerating rotor is in a set freezing temperature range; along with the rotation of the refrigerating rotor, the primary filtered saline water meets cold and freezes ice, ice crystals are attached to the refrigerating rotor, the thickness of an ice layer is gradually increased, ice crystals attached to the refrigerating rotor are stripped by an ice scraper and enter a gravity brackish water pool to carry out gravity bracketing, the ice pieces are melted to form primary fresh water, the primary fresh water is gathered and enters the primary fresh water pool, and the primary fresh water is used as raw water of a secondary freezing treatment device to carry out secondary desalination;
after the primarily filtered saline-alkali water is desalinated, the average salt content of the primary fresh water in the primary fresh water tank is 3g/l, when the salt content of the concentrated saline-alkali water reaches 9.14g/l, the threshold value of the primary concentrated water is reached, a concentrated saline-alkali water outlet valve of the primary freezing treatment device is automatically opened to discharge water, and the concentrated saline-alkali water is introduced into a high-grade saline-alkali water tank;
c) second-stage freezing treatment; the first-level fresh water enters a second-level freezing treatment device for filtering: the first-stage fresh water enters a second-stage freezing treatment device for desalination, after desalination, the average salt content of the second-stage fresh water in a second-stage fresh water tank is 2g/l, when the salt content of concentrated saline-alkali water reaches 8.43g/l, the threshold value of the second-stage concentrated water is reached, a concentrated saline-alkali water outlet valve of the second-stage freezing treatment device is automatically opened, and the concentrated saline-alkali water flows into a high-grade saline water tank;
d) desalting concentrated saline-alkali water in a high-grade saline-alkali pond: the concentrated saline-alkali water is cooled and atomized in the high-grade saline-alkali water tank to separate fresh water, the high-salinity saline-alkali water finally enters a drying yard for drying and crystallization to form salt crystal grains, and the desalination of the saline-alkali raw water is finished.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113443771A (en) * | 2021-07-07 | 2021-09-28 | 烟台大学 | Multi-stage freezing automatic water purifier and multi-stage freezing water purification method using same |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3251192A (en) * | 1961-10-10 | 1966-05-17 | Jr Wilson C Rich | Process for the conversion of salt water to fresh water |
| CN102923804A (en) * | 2012-11-15 | 2013-02-13 | 宁夏大学 | Method and device for continuously freezing high-salinity water |
| CN103265089A (en) * | 2013-05-07 | 2013-08-28 | 西安交通大学 | High temperature high efficiency multi-effect seawater distillation desalination apparatus and method |
| CN205442869U (en) * | 2016-01-28 | 2016-08-10 | 亿利资源集团有限公司 | It produces brackish water desalination system of water recovery rate to improve bitter |
| CN105884107A (en) * | 2016-05-31 | 2016-08-24 | 陈栋 | Freezing method water treatment equipment and operation method thereof |
| CN208829474U (en) * | 2018-08-02 | 2019-05-07 | 河海大学 | A kind of salt water multistage desalt processing device |
-
2021
- 2021-01-28 CN CN202110118710.4A patent/CN112875966A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3251192A (en) * | 1961-10-10 | 1966-05-17 | Jr Wilson C Rich | Process for the conversion of salt water to fresh water |
| CN102923804A (en) * | 2012-11-15 | 2013-02-13 | 宁夏大学 | Method and device for continuously freezing high-salinity water |
| CN103265089A (en) * | 2013-05-07 | 2013-08-28 | 西安交通大学 | High temperature high efficiency multi-effect seawater distillation desalination apparatus and method |
| CN205442869U (en) * | 2016-01-28 | 2016-08-10 | 亿利资源集团有限公司 | It produces brackish water desalination system of water recovery rate to improve bitter |
| CN105884107A (en) * | 2016-05-31 | 2016-08-24 | 陈栋 | Freezing method water treatment equipment and operation method thereof |
| CN208829474U (en) * | 2018-08-02 | 2019-05-07 | 河海大学 | A kind of salt water multistage desalt processing device |
Non-Patent Citations (1)
| Title |
|---|
| 李福林 等编: "《建设项目与规划水资源论证典型案例汇编》", 30 June 2020 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113443771A (en) * | 2021-07-07 | 2021-09-28 | 烟台大学 | Multi-stage freezing automatic water purifier and multi-stage freezing water purification method using same |
| CN113443771B (en) * | 2021-07-07 | 2022-06-14 | 烟台大学 | Multi-stage freezing automatic water purifier and multi-stage freezing water purification method using same |
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