Energy-saving device and energy-saving method for salt separation and crystallization
By designing a salt-dividing and crystallization energy-saving device, using steam recovery and condensate heat exchange, the problem of high energy consumption during the evaporation and concentration of high-salt wastewater is solved, and a significant reduction in energy consumption and continuous improvement of the evaporation process is achieved.
Patent Information
- Application Number
- CN202411655427.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2024-12-27
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
There is a high energy consumption problem during the evaporation and concentration of high-salt wastewater. The heat transfer temperature difference of multi-effect evaporator increases, the production intensity decreases, and external steam is needed to supplement it. After condensation, the heat is brought into the circulating water, which increases energy consumption.
An energy-saving device for salt separation crystallization is designed, including an evaporative crystallization system, a steam circulation system and a condensate system, which reduces energy consumption through steam recycling and heat exchange of condensate. The device includes one-effect, two-effect, three-effect evaporation and crystallization, a steam circulation system and a condensate system. It uses a steam compressor to increase pressure and heat the condensate, and preheat it at low temperature and high temperature to reduce external steam dependence.
It significantly reduces energy consumption, avoids the use of vacuum pumps and large-area coolers, improves the sustainability and efficiency of the evaporation process, and saves mechanical energy and circulating water load.
Smart Images
Figure CN119186011A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of high-salt concentrated water crystallization treatment, and in particular to a salt separation crystallization energy-saving device and an energy-saving method. Background Art
[0002] There is no simple, easy and low-cost method for treating high-salt wastewater at home and abroad. The wastewater generated by coal chemical enterprises generally undergoes pretreatment, sand filtration, ultrafiltration and reverse osmosis to become qualified reuse water, while the water that cannot pass through reverse osmosis becomes concentrated water. The high-salt wastewater salt separation and crystallization process is the technical basis for achieving zero-discharge of wastewater and crystallization salt resources. The concentrated water is further concentrated, dried and centrifuged through the salt separation and crystallization process to obtain sodium chloride and sodium sulfate salts, and finally sodium chloride, sodium sulfate and miscellaneous salts.
[0003] The evaporation and concentration of high-salt wastewater is the main energy consumption for salt separation. In order to improve the utilization rate of steam, double-effect evaporation, triple-effect evaporation or multi-effect evaporators are widely used in China. In multi-effect evaporation, as the number of effects increases, the temperature difference loss of heat transfer increases, which gradually reduces the production intensity of the evaporator. It is always necessary to supplement external steam, and the multi-effect evaporator only recovers a part of the raw steam heat. Finally, a cooler with a large heat exchange area is required to condense the raw steam. A lot of heat is brought into the circulating water, which increases the circulating water load and energy consumption. Summary of the invention
[0004] The purpose of the present invention is to provide a salt separation crystallization energy-saving device and energy-saving method, which reduces energy consumption and achieves the purpose of energy saving through steam recovery and utilization and heat exchange and cooling of condensate.
[0005] To achieve the above-mentioned purpose, the present invention provides a salt separation crystallization energy-saving device, comprising an evaporation crystallization system, a steam circulation system and a condensate system, the evaporation crystallization system comprising a first-effect evaporation crystallization, a second-effect evaporation crystallization and a third-effect evaporation crystallization which are connected in sequence, the pressure and temperature of the first-effect evaporation crystallization, the second-effect evaporation crystallization and the third-effect evaporation crystallization being reduced in sequence; the first-effect evaporation crystallization, the second-effect evaporation crystallization and the third-effect evaporation crystallization are connected through a steam circulation system and a condensate system, the condensate system preheats the high-concentration brine, and the high-concentration brine is connected to the first-effect evaporation crystallization.
[0006] Preferably, the single-effect evaporation crystallization comprises a single-effect heater and a single-effect crystallizer, the highly concentrated brine enters the single-effect crystallizer through the single-effect heater, a steam inlet is provided on the single-effect heater, a discharge port of the single-effect crystallizer is connected to a feed port of the single-effect heater through a single-effect connecting pipe, and a single-effect circulating pump is provided on the single-effect connecting pipe.
[0007] Preferably, the two-effect evaporation crystallization includes a two-effect heater and a two-effect crystallizer, the first-effect connecting pipe is connected to the feed port of the second-effect heater through a two-effect feed pipe, the second-effect feed pipe is provided with a two-effect circulation pump, the discharge port of the second-effect heater is connected to the feed port of the second-effect crystallizer, the discharge port of the second-effect crystallizer is provided with a two-effect connecting pipe, and the two-effect connecting pipe is connected to the two-effect feed pipe.
[0008] Preferably, the triple-effect evaporation crystallization comprises a triple-effect heater and a triple-effect crystallizer, the second-effect feed pipe is connected to the feed port of the triple-effect heater through the three-effect feed pipe, the three-effect feed pipe is provided with a three-effect circulation pump and a feed pump, the discharge port of the triple-effect heater is connected to the feed port of the three-effect crystallizer, the discharge port of the three-effect crystallizer is connected to the three-effect feed pipe through a three-effect connecting pipe, the feed pump is located between the three-effect connecting pipe and the second-effect feed pipe, and the three-effect circulation pump is located between the three-effect connecting pipe and the triple-effect heater; the three-effect crystallizer is provided with a discharge pipe, and the discharge pipe is provided with a discharge pump.
[0009] Preferably, the steam circulation system includes a first-effect exhaust pipe and a second-effect exhaust pipe, the exhaust port of the first-effect crystallizer is connected to the air inlet of the second-effect heater through the first-effect exhaust pipe, the exhaust port of the second-effect crystallizer is connected to the air inlet of the triple-effect heater through the second-effect exhaust pipe, a steam recovery pipe is provided on the exhaust port of the triple-effect crystallizer, the triple-effect crystallizer is connected to the air inlet of the steam compressor through the steam recovery pipe, and the outlet of the steam compressor is connected to the steam inlet of the first-effect heater through the steam return pipe.
[0010] Preferably, a steam injection pipe is provided on the steam recovery pipe, and the air outlet of the steam compressor is connected to the air inlet of the steam injection pipe through the steam reflux pipe.
[0011] Preferably, the steam return pipe is connected to the exhaust pipe of the first-effect crystallizer through a first-effect flushing pipe, and a first-effect steam flushing valve is provided on the first-effect flushing pipe; the steam return pipe is connected to the exhaust pipe of the second-effect crystallizer through a second-effect flushing pipe, and a second-effect steam flushing valve is provided on the second-effect flushing pipe.
[0012] Preferably, the condensate system comprises a low-temperature preheater and a high-temperature preheater, the liquid outlet of the first-effect heater is connected to the high-temperature preheater through a first-effect drain pipe, and the condensate of the first-effect heater exchanges heat with high-concentration brine in the high-temperature preheater.
[0013] Preferably, the high-temperature preheater is connected to the liquid inlet of the three-effect heater through a first-effect condenser, the liquid outlet of the second-effect heater is connected to the liquid inlet of the three-effect heater through a second-effect condenser, the liquid outlet of the three-effect heater is connected to the dirty condensed water tank through a three-effect condenser, the dirty condensed water tank is connected to the low-temperature preheater through a water tank drain pipe, a condensed water pump is provided on the water tank drain pipe, the dirty condensed water exchanges heat with high-salt concentrated water in the low-temperature preheater, and the brine outlet of the low-temperature preheater is connected to the brine inlet of the high-temperature preheater.
[0014] The energy-saving method based on the above-mentioned salt separation crystallization energy-saving device comprises the following steps: S1, the high-concentration brine is preheated by the low-temperature preheater and the high-temperature preheater and then enters the first-effect heater under the action of the first-effect circulation pump. The high-concentration brine is heated by the steam of the first-effect heater and then enters the first-effect crystallizer for crystallization. The high-concentration brine in the first-effect crystallizer is circulated and crystallized through the first-effect connecting pipe, the first-effect circulation pump and the first-effect heater; S2, the liquid in the first-effect crystallizer enters the second-effect heater through the first-effect connecting pipe, the second-effect feed pipe and the second-effect circulating pump for heating, the gas in the first-effect crystallizer enters the second-effect heater through the first-effect exhaust pipe to provide a heat source for the second-effect heater, the brine enters the second-effect crystallizer for evaporation and crystallization after being heated by the second-effect heater, and the brine circulates and crystallizes through the second-effect connecting pipe, the second-effect feed pipe, the second-effect circulating pump, the second-effect heater and the second-effect crystallizer; S3, the liquid in the second-effect crystallizer enters the three-effect heater through the second-effect connecting pipe, the second-effect feeding pipe, the second-effect circulating pump, the three-effect feeding pipe, the feed pump and the three-effect circulating pump for heating, the gas in the second-effect crystallizer enters the three-effect heater through the second-effect exhaust pipe to provide a heat source for the three-effect heater, the brine enters the three-effect crystallizer for evaporation and crystallization after being heated by the three-effect heater, the brine circulates and crystallizes through the three-effect connecting pipe, the three-effect feeding pipe, the three-effect circulating pump, the three-effect heater and the three-effect crystallizer; the brine after crystallization is completed is discharged through the discharge pump and the discharge pipe; S4. The gas in the three-effect crystallizer is connected to the steam compressor through a steam recovery pipe. The high-pressure steam at the steam compressor outlet enters the steam injection pipe through a steam return pipe as the injection power of the steam injection pipe. The steam compressor outlet enters the first-effect heater through a steam return pipe to achieve steam recovery and recycling. The steam on the steam return pipe is used to flush the outlets of the first-effect crystallizer and the second-effect crystallizer through a first-effect flushing pipe and a second-effect flushing pipe respectively. S5. The condensate from the first-effect heater enters the high-temperature preheater through the first-effect discharge pipe to perform high-temperature heat exchange with the high-salt concentrated water. The condensate from the high-temperature preheater enters the three-effect heater through the first-effect condenser pipe. The condensate from the second-effect heater enters the three-effect heater through the second-effect condenser pipe. The condensate from the three-effect heater enters the dirty condensate water tank through the three-effect condenser pipe. The condensate in the dirty condensate water tank enters the low-temperature preheater through the condensate pump and the water tank discharge pipe to perform low-temperature heat exchange with the high-concentration brine. The condensate after heat exchange is discharged for subsequent treatment.
[0015] The advantages and positive effects of the salt separation crystallization energy-saving device and energy-saving method described in the present invention are: 1. The present invention provides a steam jet pipe to draw negative pressure, which, on the one hand, maintains the energy-saving characteristics of low-temperature evaporation of the multiple-effect crystallizer, and on the other hand, does not require the installation of a vacuum pump and a circulating water cooler, and has a significant energy-saving effect.
[0016] 2. The present invention compresses the secondary steam generated by the three-effect crystallizer and transmits it to the shell side of the first-effect heater to increase the pressure and temperature through a steam compressor for use as heating steam. Only a small amount of mechanical energy is used to convert all the secondary steam into a reusable steam source, thereby allowing the evaporation process to continue without relying on external steam.
[0017] 3. The present invention makes full use of the temperature difference of the heater condensate, and preheats the feed with low-temperature and high-temperature waste condensate respectively, thereby increasing the feed temperature and reducing the discharge temperature.
[0018] 4. The present invention provides a crystallizer flushing steam pipeline to timely flush and clean the gas outlet pipeline, thereby preventing the pipeline from becoming blocked, thinner, and causing greater resistance, and maintaining negative pressure in the crystallizer, which is beneficial to energy saving and consumption reduction.
[0019] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a structural schematic diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of an evaporation crystallization system according to an embodiment of the present invention; Figure 3 A schematic diagram of the structure of a steam circulation system according to an embodiment of the present invention; Figure 4 Schematic diagram of the condensate system structure according to an embodiment of the present invention.
[0021] Reference numerals 1. Low-temperature preheater; 2. High-temperature preheater; 3. First-effect circulation pump; 4. First-effect heater; 5. First-effect crystallizer; 6. Second-effect circulation pump; 7. Second-effect heater; 8. Second-effect crystallizer; 9. Feed pump; 10. Third-effect circulation pump; 11. Third-effect heater; 12. Third-effect crystallizer; 13. Discharge pump; 14. Steam injection pipe; 15. Steam compressor; 16. First-effect steam flushing valve; 17. Second-effect steam flushing valve; 18, dirty condensate tank; 19, condensate pump; 20, second effect feed pipe; 21, discharge pipe; 22, first effect exhaust pipe; 23, second effect exhaust pipe; 24, steam recovery pipe; 25, steam return pipe; 26, steam reflux pipe; 27, first effect flushing pipe; 28, second effect flushing pipe; 29, first effect drain pipe; 30, first effect condenser; 31, second effect condenser; 32, third effect condenser; 33, water tank drain pipe. DETAILED DESCRIPTION
[0022] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the invented product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting", "installation", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0023] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.
[0024] like Figure 1 As shown. A salt separation crystallization energy-saving device includes an evaporation crystallization system, a steam circulation system and a condensate system. The evaporation crystallization system is used for evaporation crystallization of highly concentrated brine. The steam circulation system provides heat energy for the entire device. The condensate system is used for recovery of condensate and preheating of highly concentrated brine. The evaporation crystallization system includes a first-effect evaporation crystallization, a second-effect evaporation crystallization, and a third-effect evaporation crystallization connected in sequence. The pressure and temperature of the first-effect evaporation crystallization, the second-effect evaporation crystallization, and the third-effect evaporation crystallization are reduced in sequence. The first-effect evaporation crystallization, the second-effect evaporation crystallization, and the third-effect evaporation crystallization are connected through a steam circulation system and a condensate system.
[0025] like Figure 2 As shown, the first-effect evaporation crystallization includes a first-effect heater 4 and a first-effect crystallizer 5, and the highly concentrated brine enters the first-effect crystallizer 5 through the first-effect heater 4. A steam inlet is provided on the first-effect heater 4 to provide heat energy for the first-effect heater 4. The discharge port of the first-effect crystallizer 5 is connected to the feed port of the first-effect heater 4 through a first-effect connecting pipe, and a first-effect circulating pump 3 is provided on the first-effect connecting pipe to realize the circulating evaporation crystallization of the highly concentrated brine in the first-effect evaporation crystallization.
[0026] The second-effect evaporation crystallization comprises a second-effect heater 7 and a second-effect crystallizer 8, and a first-effect connecting pipe is connected to the feed port of the second-effect heater 7 through a second-effect feed pipe 20. A second-effect circulation pump 6 is arranged on the second-effect feed pipe 20. The discharge port of the second-effect heater 7 is connected to the feed port of the second-effect crystallizer 8. The discharge port of the second-effect crystallizer 8 is provided with a second-effect connecting pipe, and the second-effect connecting pipe is connected to the second-effect feed pipe 20.
[0027] The triple-effect evaporation crystallization includes a triple-effect heater 11 and a triple-effect crystallizer 12, and the second-effect feed pipe 20 is connected to the feed port of the triple-effect heater 11 through the triple-effect feed pipe. A triple-effect circulation pump 10 and a feed pump 9 are arranged on the triple-effect feed pipe. The discharge port of the triple-effect heater 11 is connected to the feed port of the triple-effect crystallizer 12. The discharge port of the triple-effect crystallizer 12 is connected to the triple-effect feed pipe through a triple-effect connecting pipe. The feed pump 9 is located between the triple-effect connecting pipe and the second-effect feed pipe 20, and the triple-effect circulation pump 10 is located between the triple-effect connecting pipe and the triple-effect heater 11. A discharge pipe 21 is arranged on the triple-effect crystallizer 12, and a discharge pump 13 is arranged on the discharge pipe 21 for discharging the brine after the crystallization treatment.
[0028] When the brine in the first-effect crystallizer 5 enters the second-effect heater 7 through the second-effect feed pipe 20, a small amount of brine will enter the three-effect heater 11 through the three-effect feed pipe, but the amount entering the three-effect heater 11 is relatively small and does not affect the overall brine treatment effect.
[0029] like Figure 3 As shown. The steam circulation system includes a first-effect exhaust pipe 22 and a second-effect exhaust pipe 23. The exhaust port of the first-effect crystallizer 5 is connected to the air inlet of the second-effect heater 7 through the first-effect exhaust pipe 22, and the exhaust port of the second-effect crystallizer 8 is connected to the air inlet of the triple-effect heater 11 through the second-effect exhaust pipe 23, so as to realize the reuse of steam between the first-effect heater 4, the second-effect heater 7 and the triple-effect heater 11. A steam recovery pipe 24 is provided on the exhaust port of the triple-effect crystallizer 12, and the triple-effect crystallizer 12 is connected to the air inlet of the steam compressor 15 through the steam recovery pipe 24. The air outlet of the steam compressor 15 is connected to the steam inlet of the first-effect heater 4 through the steam return pipe 25, so as to realize the recycling of steam and achieve the effect of energy saving.
[0030] The steam recovery pipe 24 is provided with a steam injection pipe 14, and the gas outlet of the steam compressor 15 is connected to the gas inlet of the steam injection pipe 14 through the steam reflux pipe 26, providing injection power for the steam injection pipe 14. The steam of the triple effect crystallizer 12 is purified by the separation and defoaming device at the upper part of the triple effect crystallizer 12 and then drawn into the steam injection pipe 14.
[0031] The steam return pipe 25 is connected to the exhaust pipe of the first-effect crystallizer 5 through the first-effect flushing pipe 27, and the first-effect steam flushing valve 16 is provided on the first-effect flushing pipe 27. The steam return pipe 25 is connected to the exhaust pipe of the second-effect crystallizer 8 through the second-effect flushing pipe 28, and the second-effect steam flushing valve 17 is provided on the second-effect flushing pipe 28. When the internal pressure of the first-effect crystallizer 5 and the second-effect crystallizer 8 is high, the first-effect steam flushing valve 16 and the second-effect steam flushing valve 17 are opened to flush the gas outlet pipeline, so that the crystallizer can maintain the negative pressure low-temperature evaporation state to operate, save energy consumption, and the flushing water enters the dirty condensed water tank 18 and is sent to the recycled water for treatment.
[0032] like Figure 4 The condensate system includes a low-temperature preheater 1 and a high-temperature preheater 2. The liquid outlet of the first-effect heater 4 is connected to the high-temperature preheater 2 through the first-effect drain pipe 29. The condensate of the first-effect heater 4 exchanges heat with the high-concentration brine in the high-temperature preheater 2. The high-concentration brine is preheated and heated by the condensate of the first-effect heater 4 to reduce the temperature of the condensate.
[0033] The high-temperature preheater 2 is connected to the liquid inlet of the triple-effect heater 11 through the first-effect condenser 30, the liquid outlet of the second-effect heater 7 is connected to the liquid inlet of the triple-effect heater 11 through the second-effect condenser 31, and the liquid outlet of the triple-effect heater 11 is connected to the dirty condensed water tank 18 through the third-effect condenser 32. The condensate in the first-effect heater 4, the second-effect heater 7 and the triple-effect heater 11 enters the dirty condensed water tank 18 for collection. The dirty condensed water tank 18 is connected to the low-temperature preheater 1 through the water tank drain pipe 33, and the water tank drain pipe 33 is provided with a condensed water pump 19. The dirty condensed water exchanges heat with the high-salt concentrated water in the low-temperature preheater 1, and the brine outlet of the low-temperature preheater 1 is connected to the brine inlet of the high-temperature preheater 2.
[0034] When the machine is just started, the concentrated brine is heated with external steam. The secondary steam generated by the first-effect crystallizer 5 enters the second-effect heater 7, the secondary steam generated by the second-effect crystallizer 8 enters the third-effect heater 11, and the secondary steam of the third-effect crystallizer 12 returns to the first-effect heater 4 through the steam compressor 15. As the outlet pressure of the steam compressor 15 increases, the negative pressure extraction capacity of the steam ejector gradually increases. After the steam cycle is established, the external steam is withdrawn. Normal operation controls the pressure and temperature of the circulating steam through the work of the steam compressor 15, thereby adjusting the temperature of the first-effect heater 4.
[0035] The energy-saving method based on the above-mentioned salt separation crystallization energy-saving device comprises the following steps: S1, the high-concentration brine is preheated by the low-temperature preheater 1 and the high-temperature preheater 2 and then enters the first-effect heater 4 under the action of the first-effect circulation pump 3. The high-concentration brine is heated by the steam of the first-effect heater 4 and then enters the first-effect crystallizer 5 for crystallization. The high-concentration brine in the first-effect crystallizer 5 is circulated and crystallized through the first-effect connecting pipe, the first-effect circulation pump 3 and the first-effect heater 4.
[0036] S2. The liquid in the first-effect crystallizer 5 enters the second-effect heater 7 through the first-effect connecting pipe, the second-effect feeding pipe 20 and the second-effect circulating pump 6 for heating. The gas in the first-effect crystallizer 5 enters the second-effect heater 7 through the first-effect exhaust pipe 22 to provide a heat source for the second-effect heater 7. After being heated by the second-effect heater 7, the brine enters the second-effect crystallizer 8 for evaporation and crystallization. The brine circulates and crystallizes through the second-effect connecting pipe, the second-effect feeding pipe 20, the second-effect circulating pump 6, the second-effect heater 7 and the second-effect crystallizer 8.
[0037] S3, the liquid in the second-effect crystallizer 8 enters the three-effect heater 11 through the two-effect connecting pipe, the two-effect feeding pipe 20, the two-effect circulating pump 6, the three-effect feeding pipe, the feeding pump 9 and the three-effect circulating pump 10 for heating, the gas in the second-effect crystallizer 8 enters the three-effect heater 11 through the two-effect exhaust pipe 23 to provide a heat source for the three-effect heater 11, the brine enters the three-effect crystallizer 12 for evaporation and crystallization after being heated by the three-effect heater 11, and the brine circulates and crystallizes through the three-effect connecting pipe, the three-effect feeding pipe, the three-effect circulating pump 10, the three-effect heater 11 and the three-effect crystallizer 12; the brine after crystallization is completed is discharged through the discharge pump 13 and the discharge pipe 21.
[0038] S4. The gas in the three-effect crystallizer 12 is connected to the steam compressor 15 through the steam recovery pipe 24. The high-pressure steam at the outlet of the steam compressor 15 enters the steam injection pipe 14 through the steam reflux pipe 26. As the injection power of the steam injection pipe 14, the outlet of the steam compressor 15 enters the single-effect heater 4 through the steam return pipe 25, so as to realize steam recovery and recycling. The steam on the steam return pipe 25 flushes the outlets of the first-effect crystallizer 5 and the second-effect crystallizer 8 respectively through the first-effect flushing pipe 27 and the second-effect flushing pipe 28.
[0039] S5. The condensate of the first-effect heater 4 enters the high-temperature preheater 2 through the first-effect discharge pipe 29 to perform high-temperature heat exchange with the high-salt concentrated water. The condensate of the high-temperature preheater 2 enters the three-effect heater 11 through the first-effect condenser pipe 30. The condensate of the second-effect heater 7 enters the three-effect heater 11 through the second-effect condenser pipe 31. The condensate of the three-effect heater 11 enters the dirty condensed water tank 18 through the three-effect condenser pipe 32. The condensate in the dirty condensed water tank 18 enters the low-temperature preheater 1 through the condensed water pump 19 and the water tank discharge pipe 33 to perform low-temperature heat exchange with the high-concentration brine. The condensate after heat exchange is discharged for subsequent treatment.
[0040] Therefore, by adopting the salt separation crystallization energy-saving device and energy-saving method described in the present invention, energy consumption is reduced through steam recovery and utilization and heat exchange and cooling of condensate, thereby achieving the purpose of energy saving.
[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.
Claims
1. A salt separation crystallization energy-saving device, characterized in that: The invention comprises an evaporation crystallization system, a steam circulation system and a condensate system. The evaporation crystallization system comprises a first-effect evaporation crystallization, a second-effect evaporation crystallization and a third-effect evaporation crystallization which are connected in sequence. The pressure and temperature of the first-effect evaporation crystallization, the second-effect evaporation crystallization and the third-effect evaporation crystallization are reduced in sequence. The first-effect evaporation crystallization, the second-effect evaporation crystallization and the third-effect evaporation crystallization are connected through a steam circulation system and a condensate system. The condensate system preheats the highly concentrated brine, and the highly concentrated brine is connected to the first-effect evaporation crystallization.
2. The salt separation crystallization energy-saving device according to claim 1, characterized in that: The single-effect evaporation crystallization comprises a single-effect heater and a single-effect crystallizer. High-concentration brine enters the single-effect crystallizer through the single-effect heater. A steam inlet is arranged on the single-effect heater. A discharge port of the single-effect crystallizer is connected to a feed port of the single-effect heater through a single-effect connecting pipe. A single-effect circulation pump is arranged on the single-effect connecting pipe.
3. A salt separation crystallization energy-saving device according to claim 2, characterized in that: The two-effect evaporation crystallization comprises a two-effect heater and a two-effect crystallizer, a first-effect connecting pipe is connected to the feed port of the two-effect heater through a two-effect feed pipe, a two-effect circulation pump is arranged on the two-effect feed pipe, a discharge port of the two-effect heater is connected to the feed port of the two-effect crystallizer, a two-effect connecting pipe is arranged at the discharge port of the two-effect crystallizer, and the two-effect connecting pipe is connected to the two-effect feed pipe.
4. The salt separation crystallization energy-saving device according to claim 3 is characterized in that: The three-effect evaporation crystallization comprises a three-effect heater and a three-effect crystallizer. The second-effect feed pipe is connected with the feed port of the three-effect heater through the three-effect feed pipe. The three-effect feed pipe is provided with a three-effect circulation pump and a feeding pump. The discharge port of the three-effect heater is connected with the feed port of the three-effect crystallizer. The discharge port of the three-effect crystallizer is connected with the three-effect feed pipe through a three-effect connecting pipe. The feeding pump is located between the three-effect connecting pipe and the second-effect feed pipe. The three-effect circulation pump is located between the three-effect connecting pipe and the three-effect heater. The three-effect crystallizer is provided with a discharge pipe, and the discharge pipe is provided with a discharge pump.
5. The salt separation crystallization energy-saving device according to claim 4 is characterized in that: The steam circulation system comprises a first-effect exhaust pipe and a second-effect exhaust pipe, the exhaust port of the first-effect crystallizer is connected to the air inlet of the second-effect heater via the first-effect exhaust pipe, the exhaust port of the second-effect crystallizer is connected to the air inlet of the triple-effect heater via the second-effect exhaust pipe, a steam recovery pipe is arranged on the exhaust port of the triple-effect crystallizer, the triple-effect crystallizer is connected to the air inlet of the steam compressor via the steam recovery pipe, and the air outlet of the steam compressor is connected to the steam inlet of the first-effect heater via the steam return pipe.
6. The salt separation crystallization energy-saving device according to claim 5, characterized in that: The steam recovery pipe is provided with a steam injection pipe, and the air outlet of the steam compressor is connected to the air inlet of the steam injection pipe through the steam reflux pipe.
7. The salt separation crystallization energy-saving device according to claim 5, characterized in that: The steam return pipe is connected to the exhaust pipe of the first-effect crystallizer through a first-effect flushing pipe, and a first-effect steam flushing valve is provided on the first-effect flushing pipe; the steam return pipe is connected to the exhaust pipe of the second-effect crystallizer through a second-effect flushing pipe, and a second-effect steam flushing valve is provided on the second-effect flushing pipe.
8. The salt separation crystallization energy-saving device according to claim 4, characterized in that: The condensate system comprises a low-temperature preheater and a high-temperature preheater. The liquid outlet of the first-effect heater is connected to the high-temperature preheater through a first-effect drain pipe. The condensate of the first-effect heater exchanges heat with highly concentrated brine in the high-temperature preheater.
9. The salt separation crystallization energy-saving device according to claim 8, characterized in that: The high-temperature preheater is connected to the liquid inlet of the three-effect heater through a first-effect condenser, the liquid outlet of the second-effect heater is connected to the liquid inlet of the three-effect heater through the second-effect condenser, the liquid outlet of the three-effect heater is connected to the dirty condensed water tank through the three-effect condenser, the dirty condensed water tank is connected to the low-temperature preheater through a water tank drain pipe, a condensed water pump is provided on the water tank drain pipe, the dirty condensed water exchanges heat with high-salt concentrated water in the low-temperature preheater, and the brine outlet of the low-temperature preheater is connected to the brine inlet of the high-temperature preheater.
10. An energy-saving method for a salt separation crystallization energy-saving device according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, the high-concentration brine is preheated by the low-temperature preheater and the high-temperature preheater and then enters the first-effect heater under the action of the first-effect circulation pump. The high-concentration brine is heated by the steam of the first-effect heater and then enters the first-effect crystallizer for crystallization. The high-concentration brine in the first-effect crystallizer is circulated and crystallized through the first-effect connecting pipe, the first-effect circulation pump and the first-effect heater; S2, the liquid in the first-effect crystallizer enters the second-effect heater through the first-effect connecting pipe, the second-effect feed pipe and the second-effect circulating pump for heating, the gas in the first-effect crystallizer enters the second-effect heater through the first-effect exhaust pipe to provide a heat source for the second-effect heater, the brine enters the second-effect crystallizer for evaporation and crystallization after being heated by the second-effect heater, and the brine circulates and crystallizes through the second-effect connecting pipe, the second-effect feed pipe, the second-effect circulating pump, the second-effect heater and the second-effect crystallizer; S3, the liquid in the second-effect crystallizer enters the three-effect heater through the second-effect connecting pipe, the second-effect feed pipe, the second-effect circulation pump, the three-effect feed pipe, the feed pump and the three-effect circulation pump for heating, the gas in the second-effect crystallizer enters the three-effect heater through the second-effect exhaust pipe to provide a heat source for the three-effect heater, the brine enters the three-effect crystallizer for evaporation and crystallization after being heated by the three-effect heater, and the brine circulates and crystallizes through the three-effect connecting pipe, the three-effect feed pipe, the three-effect circulation pump, the three-effect heater and the three-effect crystallizer; After the crystallization is completed, the brine is discharged through the discharge pump and the discharge pipe; S4. The gas in the three-effect crystallizer is connected to the steam compressor through a steam recovery pipe. The high-pressure steam at the steam compressor outlet enters the steam injection pipe through a steam return pipe as the injection power of the steam injection pipe. The steam compressor outlet enters the first-effect heater through a steam return pipe to achieve steam recovery and recycling. The steam on the steam return pipe is used to flush the outlets of the first-effect crystallizer and the second-effect crystallizer through a first-effect flushing pipe and a second-effect flushing pipe respectively. S5. The condensate from the first-effect heater enters the high-temperature preheater through the first-effect discharge pipe to perform high-temperature heat exchange with the high-salt concentrated water. The condensate from the high-temperature preheater enters the three-effect heater through the first-effect condenser pipe. The condensate from the second-effect heater enters the three-effect heater through the second-effect condenser pipe. The condensate from the three-effect heater enters the dirty condensate water tank through the three-effect condenser pipe. The condensate in the dirty condensate water tank enters the low-temperature preheater through the condensate pump and the water tank discharge pipe to perform low-temperature heat exchange with the high-concentration brine. The condensate after heat exchange is discharged for subsequent treatment.