Negative-pressure evaporation desalting device for salt-containing wastewater

Abstract

The utility model discloses a salt-containing wastewater negative pressure evaporation desalting device which is of an integrated structure and reduces occupied land and heat loss. A saturated liquid circulating pump outlet of the equipment is connected with a cold flow inlet through a pipeline, and a cold flow outlet is connected with a saturated liquid flash evaporation pipe through a pipeline; the hot flow outlet is connected into the condensate water tank through a pipeline; the crystallization liquid inlet is connected with an outlet of the supersaturated liquid circulating pump through a pipeline, and the primary steam outlet is connected with the heat flow inlet through a pipeline; a suction inlet of the cold water circulating pump is communicated with the water collecting area, the second-stage heat exchanger is a plate heat exchanger, and a hot flow outlet of the second-stage heat exchanger is connected into a secondary steam inlet through a pipeline; and the heat flow inlet is connected with the flash evaporation secondary steam outlet and the drying secondary steam outlet through pipelines. The water cooling tower provided by the utility model evaporates and cools the jet water absorbing heat, the jet water is recycled after the water temperature is reduced by 5-10 DEG C, and the salt-free water generated by secondary steam condensation is discharged out of the quick-cooling negative-pressure device, so that the negative-pressure evaporation desalting of the salt-containing wastewater is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of saline wastewater treatment, in particular to a negative pressure evaporation and desalination device for saline wastewater. Background Art

[0002] There are many ways to produce saline wastewater, and the amount of saline wastewater is increasing year by year. Saline wastewater mainly comes from the petrochemical, pharmaceutical, food processing, electroplating, printing and dyeing industries. The water quality of these wastewaters is complex. In addition to containing a large amount of inorganic salts, they also contain a large amount of organic pollutants. Wastewater desalination is recognized as a highly difficult wastewater treatment project. It is particularly important to choose effective saline wastewater treatment equipment. Traditional desalination devices have poor desalination effects and are often unable to completely remove the salt from the wastewater. Evaporation desalination equipment cannot operate stably and continuously. As the water in the evaporation equipment becomes increasingly concentrated, the evaporation equipment needs to be shut down for cleaning after a period of operation. Otherwise, the evaporation efficiency will become lower and lower until it cannot operate, seriously affecting the overall desalination efficiency.

[0003] The application with publication number CN116282289A provides a salt-containing wastewater evaporation and desalination device, which belongs to the field of wastewater desalination technology; the salt-containing wastewater evaporation and desalination device is connected to a wastewater source, and its characteristics are that the salt-containing wastewater evaporation and desalination device includes: a water inlet pipe, a first heat exchanger, a concentration crystallization tank, a first circulation pump, a three-way valve, a circulation liquid inlet, a drying tank assembly, a second discharge port, a hydraulic ejector, a cooling tower device and a second circulation pump; the first circulation pump injects a high-concentration salt-containing solution that has been vaporized in the concentration crystallization tank into the three-way valve, and then refluxes it into the concentration crystallization tank through the circulation liquid inlet, thereby realizing the circulation of the high-concentration salt-containing solution, so as to avoid the crystallization salt of the high-concentration salt-containing solution from being deposited in the concentration crystallization tank, thereby avoiding the situation where the concentration crystallization tank needs to be shut down due to the need to clean the crystallization salt in the concentration crystallization tank.

[0004] The above patent is about a desalination device for saline wastewater, which uses a drying tank assembly to dry the concentrated brine. The split layout increases the equipment footprint and heat loss. The present invention adopts an integrated structure, which reduces the footprint and heat loss, improves the equipment desalination efficiency, and reduces equipment investment. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a negative pressure evaporation desalination device for saline wastewater, which adopts an integrated structure, reduces space occupation and heat loss, improves the desalination efficiency of the equipment, and reduces equipment investment.

[0006] The technical solution adopted by the present invention is: a negative pressure evaporation and desalination device for saline wastewater, the negative pressure evaporation and desalination device for saline wastewater includes a water inlet pipe 1, a flash evaporation concentration crystallization device 2, a rapid cooling negative pressure device 4, a primary heat exchanger 5, a secondary heat exchanger 6, a condensed water tank 24, and a water outlet pipe 44. The flash evaporation concentration crystallization device 2 includes a liquid inlet pipe 45, a flash chamber 12, a crystallization drying chamber 3, a steam heating chamber 29, a crystallization separation chamber 47, a primary steam inlet 30, a primary steam outlet 31, a flash secondary steam outlet 11, a drying secondary steam outlet 32, a slag outlet 33, a crystallization liquid inlet 34, a supersaturated liquid outlet 17, a supersaturated liquid circulation inlet 18, an unsaturated liquid circulation pump 7, and a supersaturated liquid circulation pump 8. Saturated liquid circulation pump 8, unsaturated liquid flash pipe 19, drive device 28, the flash chamber 12 is provided with an overflow cap 13 and a water distribution cone hopper 14; the crystallization drying chamber 3 is separated from the outside by an inner cylinder 25, and a scraper 27 and a stirring shaft 26 are provided in the chamber; the heating chamber 29 is provided with fins 48; the crystallization separation chamber 47 is provided with an inner partition cone hopper 15 and a downpipe 16; the liquid inlet pipe 45 and the saturated liquid circulation pump 7 suction port are connected to the upper area of ​​the crystallization separation chamber 47; the supersaturated liquid outlet 17, the supersaturated liquid circulation inlet 18, and the downpipe 16 outlet are connected to the lower area of ​​the crystallization separation chamber 47; the first-stage heat exchanger 5 is a plate heat exchanger, including a first-stage heat exchanger cold flow inlet 20, a cold flow outlet 22 of the first-stage heat exchanger, a hot flow inlet 21 of the first-stage heat exchanger, and a hot flow outlet 23 of the first-stage heat exchanger; characterized in that: the outlet of the saturated liquid circulation pump 7 is connected to the cold flow inlet 20 by a pipeline, and the cold flow outlet 22 is connected to the saturated liquid flash pipe 19 by a pipeline; the hot flow outlet 23 is connected to the condensation water tank 24 by a pipeline; the crystallization liquid inlet 34 is connected to the outlet of the supersaturated liquid circulation pump 8 by a pipeline, and the primary steam outlet 31 is connected to the hot flow inlet 21 by a pipeline; the rapid cooling negative pressure device 4 includes a cold water circulation pump 9, a hydraulic ejector 10, a cooling water area 42, and a water collection area 43; the hydraulic ejector 10 includes a cold water inlet 39, an absorption liquid outlet 40, and a secondary steam inlet 41; The suction port of the cold water circulation pump 9 is connected to the water collecting area, the outlet of the cold water circulation pump 9 is connected to the cold water inlet 39 through a pipe, and the absorption liquid outlet 40 is connected to the cold water area 42; the water collecting area 43 is provided with an overflow outlet connected to the outlet pipe 44; the secondary heat exchanger 6 is a plate heat exchanger, including a secondary heat exchanger cold flow inlet 37, a secondary heat exchanger cold flow outlet 38, a secondary heat exchanger hot flow inlet 35, and a secondary heat exchanger hot flow outlet 36; the water inlet pipe 1 is connected to the secondary heat exchanger cold flow inlet 37, and the cold flow outlet 38 is connected to the liquid inlet pipe 45 through a pipe; the hot flow outlet 36 is connected to the secondary steam inlet 41 through a pipe; the hot flow inlet 35 is connected to the flash secondary steam outlet 11 and the drying secondary steam outlet 32 ​​through a pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Attachment Figure 1Schematic diagram of system connection of the present utility model.

[0008] Attachment Figure 2 Figure 1 Middle AA section view.

[0009] Attachment Figure 3 Figure 1 Middle BB cross-section view.

[0010] Attachment Figure 4 Figure 1 Center C view.

[0011] Attachment Figure 5 Figure 1 Center D view. DETAILED DESCRIPTION

[0012] Reference Figure 1The components are connected as shown. The utility model relates to a negative pressure evaporation and desalination device for saline wastewater, including a water inlet pipe 1, a flash concentration crystallization device 2, a rapid cooling negative pressure device 4, a primary heat exchanger 5, a secondary heat exchanger 6, a condensed water tank 24, and a water outlet pipe 44. The flash concentration crystallization device 2 includes a liquid inlet pipe 45, a flash chamber 12, a crystallization drying chamber 3, a steam heating chamber 29, a crystallization separation chamber 47, a primary steam inlet 30, a primary steam outlet 31, a flash secondary steam outlet 11, a drying secondary steam outlet 32, a slag outlet 33, a crystallization liquid inlet 34, a supersaturated liquid outlet 17, a supersaturated liquid circulation inlet 18, an unsaturated liquid circulation pump 7, a supersaturated liquid circulation pump 8, an unsaturated liquid flash pipe 19, and a driving device 28. The flash chamber 12 is provided with an overflow prevention cap 13 and a water distribution cone hopper 14; the crystallization drying chamber 3 is separated from the outside by an inner cylinder 25, and a scraper 27 and a stirring shaft 26 are provided in the chamber; the heating chamber 29 is provided with a fin 48; the crystallization separation chamber 47 is provided with an inner partition cone hopper 15 and a downpipe 16; the liquid inlet pipe 45 and the suction port of the unsaturated liquid circulation pump 7 are connected to the upper area (unsaturated area) of the crystallization separation chamber 47; the supersaturated liquid outlet 17, the supersaturated liquid circulation inlet 18, and the downpipe 1 6 outlet is connected to the lower area (supersaturated area) of the crystallization separation chamber 47; the first-stage heat exchanger 5 is a plate heat exchanger, including a cold flow inlet 20, a cold flow outlet 22, a hot flow inlet 21, and a hot flow outlet 23; it is characterized in that: the outlet of the unsaturated liquid circulation pump 7 is connected to the cold flow inlet 20 through a pipeline, the cold flow outlet 22 is connected to the unsaturated liquid flash pipe 19 through a pipeline; the hot flow outlet 23 is connected to the condensation water tank 24 through a pipeline; the crystallization liquid inlet 34 is connected to the outlet of the supersaturated liquid circulation pump 8 through a pipeline, and ... the first-stage heat exchanger 5 is a plate heat exchanger, The secondary steam outlet 31 is connected to the hot flow inlet 21 through a pipeline; the rapid cooling negative pressure device 4 includes a cold water circulation pump 9, a hydraulic ejector 10, a cold water area 42, and a water collection area 43; the hydraulic ejector 10 includes a cold water inlet 39, an absorption liquid outlet 40, and a secondary steam inlet 41; the cold water circulation pump 9 suction port is connected to the water collection area, the cold water circulation pump 9 outlet is connected to the cold water inlet 39 through a pipeline, and the absorption liquid outlet 40 is connected to the cold water area 42; the water collection area 43 is provided with an overflow outlet connected to the water outlet pipe 44; the two The secondary heat exchanger 6 is a plate heat exchanger, including a secondary heat exchanger cold flow inlet 37, a secondary heat exchanger cold flow outlet 38, a secondary heat exchanger hot flow inlet 35, and a secondary heat exchanger hot flow outlet 36; the water inlet pipe 1 is connected to the secondary heat exchanger cold flow inlet 37, and the secondary heat exchanger cold flow outlet 38 is connected to the liquid inlet pipe 45 through a pipe; the secondary heat exchanger hot flow outlet 36 is connected to the secondary steam inlet 41 through a pipe; the secondary heat exchanger hot flow inlet 35 is connected to the flash secondary steam outlet 11 and the drying secondary steam outlet 32 ​​through pipes.The crystallization drying chamber is located between the flash chamber and the steam heating chamber, the steam heating chamber is located at the bottom of the crystallization drying chamber, and a flow channel is left between the outer shell of the crystallization drying chamber and the outer shell of the flash chamber. The channel width is 100-500mm, so that the flash chamber and the crystallization separation chamber are connected.

[0013] The crystallization drying chamber 3 is provided with a stirring shaft 26 and a scraper 27. The scraper 27 is spiral with a spiral angle of 45-60 degrees. The gap between the outer edge of the scraper 27 and the inner wall of the chamber is 0.5-1.5 mm.

[0014] The rapid cooling negative pressure device adopts a cooling water tower + hydraulic jet pump to provide negative pressure conditions, with a pressure range of -0.06 to -0.09 MPa, and the cooling water temperature drops by 5-10°C. The hydraulic jet pump can realize wall-free heat exchange, quickly absorb secondary steam, and condense it.

Claims

1. A negative pressure evaporation and desalination device for saline wastewater, comprising a water inlet pipe (1), a flash evaporation concentration crystallization device (2), a rapid cooling negative pressure device (4), a primary heat exchanger (5), a secondary heat exchanger (6), a condensed water tank (24), and a water outlet pipe (44); the flash evaporation concentration crystallization device (2) comprises a liquid inlet pipe (45), a flash evaporation chamber (12), a crystallization drying chamber (3), a steam heating chamber (29), a crystallization separation chamber (47), a primary steam inlet (30), a primary steam outlet (31), a flash secondary steam outlet (11), a drying secondary steam outlet (32), a slag outlet (33), a crystallization liquid inlet (34), a supersaturated liquid outlet (17), a supersaturated liquid circulation inlet (18), an unsaturated liquid circulation pump (7), a supersaturated liquid circulation pump (8), an unsaturated liquid flash evaporation pipe (19), and a driving device (28); The flash chamber (12) is provided with an overflow prevention cap (13) and a water distribution cone bucket (14); the crystallization drying chamber (3) is separated from the outside by an inner cylinder (25), and a scraper (27) and a stirring shaft (26) are provided in the chamber; the heating chamber (29) is provided with a fin (48); the crystallization separation chamber (47) is provided with an inner partition cone bucket (15) and a lower liquid pipe (16); the liquid inlet pipe (45) and the saturated liquid circulation pump (7) suction port are communicated with the upper area of ​​the crystallization separation chamber (47); the supersaturated liquid outlet (17), the supersaturated liquid circulation inlet (18), and the outlet of the lower liquid pipe (16) are communicated with the lower area of ​​the crystallization separation chamber (47); the first-stage heat exchanger (5) is a plate heat exchanger, including a first-stage heat exchanger cold flow inlet (20), a first-stage heat exchanger cold flow outlet (22), a first-stage heat exchanger hot flow inlet (21), and a first-stage heat exchanger hot flow outlet (23); characterized in that: The outlet of the saturated liquid circulation pump (7) is connected to the cold flow inlet (20) through a pipeline, and the cold flow outlet (22) is connected to the saturated liquid flash pipe (19) through a pipeline; the hot flow outlet (23) is connected to the condensation water tank (24) through a pipeline; the crystallization liquid inlet (34) is connected to the outlet of the supersaturated liquid circulation pump (8) through a pipeline, and the primary steam outlet (31) is connected to the hot flow inlet (21) through a pipeline; the rapid cooling negative pressure device (4) includes a cold water circulation pump (9), a hydraulic ejector (10), a cold water area (42), and a water collection area (43); the hydraulic ejector (10) includes a cold water inlet (39), an absorption liquid outlet (40), and a secondary steam inlet (41); the cold water circulation pump (9) suction port is connected to the water collection area, and the cold water circulation pump ( 9) outlet is connected to the cold water inlet (39) through a pipeline, and the absorption liquid outlet (40) is connected to the cold water area (42); the water receiving area (43) is provided with an overflow outlet connected to the water outlet pipe (44); the secondary heat exchanger (6) is a plate heat exchanger, including a secondary heat exchanger cold flow inlet (37), a secondary heat exchanger cold flow outlet (38), a secondary heat exchanger hot flow inlet (35), and a secondary heat exchanger hot flow outlet (36); the water inlet pipe (1) is connected to the secondary heat exchanger cold flow inlet (37), and the cold flow outlet (38) is connected to the liquid inlet pipe (45) through a pipeline; the hot flow outlet (36) is connected to the secondary steam inlet (41) through a pipeline; the hot flow inlet (35) is connected to the flash secondary steam outlet (11) and the drying secondary steam outlet (32) through a pipeline.

2. The negative pressure evaporation and desalination device for saline wastewater according to claim 1, characterized in that: The crystallization drying chamber is located between the flash chamber and the steam heating chamber, the steam heating chamber is located at the bottom of the crystallization drying chamber, and a flow channel is left between the outer shell of the crystallization drying chamber and the outer shell of the flash chamber. The channel width is 100-500mm, so that the flash chamber and the crystallization separation chamber are connected.

3. The negative pressure evaporation and desalination device for saline wastewater according to claim 1, characterized in that: The crystallization drying chamber (3) is provided with a stirring shaft (26) and a scraper (27). The scraper (27) is spiral-shaped with a spiral angle of 45-60 degrees. The gap between the outer edge of the scraper (27) and the inner wall of the chamber is 0.5-1.5 mm.

4. The negative pressure evaporation and desalination device for saline wastewater according to claim 1, characterized in that: The rapid cooling negative pressure device adopts a cooling water tower + hydraulic jet pump to provide negative pressure conditions, with a pressure range of -0.06 to -0.09 MPa, and the cooling water temperature drops by 5-10°C. The hydraulic jet pump can realize wall-free heat exchange, quickly absorb secondary steam, and condense it.

Images