A flash evaporation and concentration system and method for high-salt wastewater from hazardous waste incineration

Abstract

This invention relates to the field of high-salinity wastewater treatment, and provides a waste heat flash evaporation concentration system and method for high-salinity wastewater from hazardous waste incineration. The system includes a concentration tower and a salt outlet system, and a wastewater flash evaporation system. The hazardous waste incineration system is sequentially connected to a waste heat boiler, a quench tower, a dust collector, the concentration tower and salt outlet system, a deacidification tower, and a chimney, so that flue gas flows through sequentially and is discharged from the chimney. The concentrated brine from the demineralized water preparation system and the high-salinity wastewater from the deacidification tower are respectively connected to a high-salinity wastewater storage tank. The steam from the waste heat boiler is connected to the wastewater flash evaporation system. The high-salinity wastewater storage tank is connected to the wastewater flash evaporation system. The wastewater flash evaporation system is connected to the concentration tower and the salt outlet system. The entire system fully integrates the existing process characteristics of the hazardous waste incineration line, effectively achieving low-cost concentration and volume reduction of high-salinity wastewater. Compared with conventional high-salinity wastewater treatment systems, it has advantages such as low operating cost, small footprint, easy expansion, and less clogging.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-salinity water treatment, and particularly relates to a high-salinity waste water flash evaporation and concentration system and method. BACKGROUND

[0002] The high-salinity waste water generated by a hazardous waste incineration system contains a large amount of salt and organic pollutants, and the water quality is alkaline. Such high-salinity waste water is not suitable for treatment by physical and chemical or biological treatment technologies. At present, a desalted water preparation system, such as a reverse osmosis membrane treatment device, is usually arranged in a hazardous waste incineration plant to achieve treatment of the high-salinity waste water. However, although the reverse osmosis technology can achieve reduction of the high-salinity waste water, disposal of the concentrated salt water generated by the reverse osmosis is more difficult.

[0003] At present, the main technologies applied to evaporation of high-salinity waste water are mechanical vapor recompression (MVR) and multiple-effect evaporation (MED). Both of these two evaporation methods need to consume clean energy. The mechanical vapor recompression is a kind of evaporation form in which low-grade steam is compressed by a steam compressor to work to raise the steam to high-grade steam as an evaporation heat source, and the power consumption per ton of water is between 45 and 60 kW.h. The multiple-effect evaporation is a kind of evaporation form in which clean steam is used as energy, and the second steam of the previous effect is used as a heat source. The most commonly used three-effect evaporation consumes about 0.4 t of steam and 10-15 kW.h of electric energy per ton of water (per hour). Although the MVR and MED technologies can reduce energy consumption by recycling steam, a large amount of energy is still needed in the initial heating stage, which makes the whole treatment process costly.

[0004] In addition, in the evaporation process of the high-salinity waste water, the temperature of the waste water decreases rapidly, and various salt and alkali substances in the waste water will appear supersaturation and precipitate salt crystals in the heat exchange process. These salt crystals will mix with suspended solids and other solid pollutants in the waste water and adhere to the surface of the heat exchange wall to form fouling, which causes pollution, corrosion or blockage of the heat exchange wall, and long-time operation leads to damage of the equipment and even system paralysis.

[0005] In addition, in the treatment technology of the high-salinity waste water derived from hazardous waste incineration, there is no comprehensive high-salinity waste water evaporation treatment system that is well combined with the hazardous waste incineration system. If the existing high-salinity waste water evaporation process is directly used, not only will there be the problems of fouling, corrosion and equipment degradation of the equipment heat exchange surface, but also there will be problems of high operation cost and high energy consumption. SUMMARY

[0006] The present application provides a high-salinity waste water flash evaporation and concentration system and method to solve the problems of high operation cost, high energy consumption and easy blockage of the equipment in the treatment process of the high-salinity waste water generated by hazardous waste incineration in the prior art.

[0007] The application provides a hazardous waste incineration high-salinity wastewater waste heat flash evaporation concentration system, which comprises a hazardous waste incineration system, a desalted water preparation system, a high-salinity wastewater storage tank, a waste heat boiler, a quenching tower, a deacidification tower, a dust remover and a chimney, and further comprises a concentration tower and a salt discharge system and a wastewater flash evaporation system; the hazardous waste incineration system is sequentially connected with the waste heat boiler, the quenching tower, the dust remover, the concentration tower and the salt discharge system, the deacidification tower and the chimney so that flue gas sequentially flows through the chimney and is discharged from the chimney; the desalted water preparation system and the deacidification tower are connected with the high-salinity wastewater storage tank respectively so that concentrated salt water of the desalted water preparation system and high-salinity wastewater generated by the deacidification tower are respectively introduced into the high-salinity wastewater storage tank; the waste heat boiler is connected with the wastewater flash evaporation system so that steam generated by the waste heat boiler is introduced into the wastewater flash evaporation system; the high-salinity wastewater storage tank is connected with the wastewater flash evaporation system so that high-salinity wastewater in the high-salinity wastewater storage tank is introduced into the wastewater flash evaporation system; the wastewater flash evaporation system is connected with the concentration tower and the salt discharge system so that high-salinity concentrated water after flash evaporation is introduced into the concentration tower and the salt discharge system for further concentration and discharge of solid-phase crystalline salt.

[0008] Optionally, desalted water of the desalted water preparation system is connected with the waste heat boiler so as to recover the desalted water as boiler water; and condensed water of the wastewater flash evaporation system is connected with the quenching tower so as to recycle the condensed water obtained by flash evaporation.

[0009] Optionally, the wastewater flash evaporation system comprises a steam heater connected with the waste heat boiler, n-stage flash evaporators and n-stage condensers, wherein n is an integer greater than or equal to 1; each stage of flash evaporator is provided with a steam outlet, a flash evaporator wastewater inlet and a flash evaporator wastewater outlet; each stage of condenser is provided with a steam inlet, a condenser wastewater inlet, a condenser wastewater outlet, a non-condensable gas outlet and a condensed water outlet; each stage of condenser is a tubular condenser, the tube side of the condenser is high-salinity wastewater, and the shell side of the condenser is steam; the steam outlet of each stage of flash evaporator is connected with the steam inlet of the same stage of condenser; the steam heater, the first-stage flash evaporator, the second-stage flash evaporator, the third-stage flash evaporator, the (n-1)-stage flash evaporator, the n-stage flash evaporator, the (n-1)-stage condenser, the (n-2)-stage condenser, the second-stage condenser, the first-stage condenser and the steam heater are sequentially connected to form a circulation loop of high-salinity wastewater; the flash evaporator wastewater outlet of the n-stage flash evaporator is connected with the concentration tower and the salt discharge system; the condenser wastewater inlet of the (n-1)-stage condenser is connected with the high-salinity wastewater storage tank; and the n-stage condenser is connected with circulating cooling water.

[0010] Optionally, a condensed water control valve is arranged at the condensed water outlet of each stage of condenser; a non-condensable gas control valve is arranged at the non-condensable gas outlet of each stage of condenser; the condensed water outlet is connected with a fresh water storage tank, the fresh water storage tank is connected with the quenching tower or other water end; and the non-condensable gas outlet of the condenser is connected with a vacuum pump through the non-condensable gas control valve.

[0011] Optionally, a wastewater outlet control valve is arranged between the wastewater outlet of each flash evaporator and the wastewater inlet of the next stage flash evaporator; the wastewater outlet of the nth stage flash evaporator is connected to the wastewater inlet of the (n-1)th stage condenser through a wastewater circulating pump and to the concentration tower and salt discharge system through a wastewater discharge pump.

[0012] Optionally, the n is 1-15.

[0013] Optionally, the flash evaporators are vertically connected in series to enable the high-salinity wastewater to enter the next stage flash evaporator under the action of gravity; the condensers are vertically connected in series; the circulating cooling water of the nth stage condenser is fed from top to bottom.

[0014] Optionally, the concentration tower and salt discharge system comprise a concentration tower, which is provided from top to bottom with a washing spray layer, a demister layer and a circulating spray layer, and has a high-salinity wastewater slurry at the bottom; the top of the concentration tower is provided with a wastewater inlet connected to the washing spray layer, which is connected to the high-salinity concentrated water from the flash evaporation system; the concentration tower is provided with a flue gas inlet connected to the flue gas outlet of the dust remover, which is arranged below the circulating spray layer; the top of the concentration tower is provided with a flue gas outlet connected to the flue gas inlet of the deacidification tower; the high-salinity wastewater slurry is connected to the circulating spray layer through a slurry circulating pump; the bottom of the concentration tower is provided with a slurry discharge outlet connected to a thick solid-liquid separation device to obtain solid crystalline salt.

[0015] In the second aspect of the present application, a method for treating high-salinity wastewater by using the above-mentioned hazardous waste incineration high-salinity wastewater waste heat flash evaporation concentration system is provided; the flue gas generated by the hazardous waste incineration system is sequentially introduced into a waste heat boiler to recover heat, an emergency cooling tower to cool down, a dust remover to remove dust, a concentration tower and salt discharge system to contact and exchange heat with the high-salinity concentrated water therein, a deacidification tower to remove acid, and then discharged to the outside atmosphere through a chimney; the concentrated brine generated by the desalted water preparation system and the high-salinity wastewater generated by the deacidification tower are concentrated in a high-salinity wastewater storage tank, and the high-salinity wastewater in the high-salinity wastewater storage tank is introduced into the wastewater flash evaporation system for flash evaporation as the high-salinity wastewater supplement of the circulating loop; the desalted water generated by the desalted water preparation system is introduced into the waste heat boiler as boiler water; the waste heat boiler uses the flue gas waste heat of the hazardous waste incineration system to form steam from the process water including the desalted water generated by the desalted water preparation system, and generates saturated steam into the wastewater flash evaporation system for heating the high-salinity wastewater to be flashed; the heated high-salinity wastewater to be flashed is flashed in the wastewater flash evaporation system, and the high-salinity concentrated water after flashing is introduced into the concentration and salt discharge system for further concentration treatment, further concentration and solid-liquid separation, and discharge of solid crystalline salt; the condensed water generated by the wastewater flash evaporation system is introduced into the emergency cooling tower as process make-up water.

[0016] Optionally, the steam generated by the waste heat boiler is saturated steam at 165-240℃, the temperature of the high-salinity wastewater after heating is ≥110℃, and the temperature of the high-salinity wastewater after flashing in the wastewater flashing system is 45-55℃; the wastewater flashing system comprises multiple flash evaporators connected in series, and the temperature drop of each flash evaporator is 12-18℃.

[0017] Optionally, the method for treating high-salinity wastewater by using the hazardous waste incineration high-salinity wastewater waste heat flashing and concentrating system can further comprise the following steps:

[0018] S1: The 165-240℃ saturated steam generated by the waste heat boiler enters the steam heater to heat the high-salinity wastewater in the wastewater flashing system to a temperature of ≥110℃;

[0019] S2: The high-temperature high-salinity wastewater enters the multiple flash evaporators and is reduced to 45-55℃ after multiple flashing; in the wastewater flashing system, the secondary steam of each stage is drawn from the flash evaporator and sent to the condenser as a heating source for the circulating high-salinity wastewater; the condensed water generated by the multiple condensers is collected and sent to the quench tower as process make-up water or is introduced into other water-consuming ends;

[0020] The temperature drop of each flash evaporator is 12-18℃; after the multiple flashing is completed, the high-salinity wastewater is mixed with the high-salinity wastewater make-up from the high-salinity wastewater storage tank, absorbs the flashing heat brought by the secondary steam of each flash evaporator in the multiple condensers in turn, is heated to a certain temperature by the multiple condensers, and then enters the steam heater again to be reheated, so that the circulating flashing is realized;

[0021] S3: The high-salinity concentrated water generated by the wastewater flashing system is discharged to the concentration tower and the salt discharge system through the wastewater discharge pump, and at the same time, the high-salinity wastewater storage tank is used to supply water to the wastewater flashing system to maintain the working medium balance of the system; a vacuum pump is arranged at the end of the wastewater flashing system to continuously extract the non-condensable gas in each condenser, so as to maintain the negative pressure state of the wastewater flashing system and ensure the normal and stable operation of the system;

[0022] S4: The high-salinity concentrated water discharged from the wastewater flashing system is sent to the concentration tower and the salt discharge system for further concentration and solid-liquid separation, and the solid-phase crystalline salt is discharged; in the process, the flue gas discharged from the dust collector is introduced into the concentration tower and the salt discharge system to make the flue gas directly contact with the high-salinity concentrated water, so as to further concentrate the high-salinity concentrated water by using the waste heat of the flue gas.

[0023] Optionally, the TDS of the high-salinity wastewater to be treated by the hazardous waste incineration high-salinity wastewater waste heat flashing and concentrating system is 20000-80000mg / L, and the salt content is 1-15%.

[0024] Optionally, the concentration ratio of the high-salinity wastewater after treatment is 2-15.

[0025] The hazardous waste incineration high-salt wastewater waste heat flash evaporation concentration system of the present application is a comprehensive system effectively combining the high-salt wastewater treatment system and the related process devices of the hazardous waste incineration system. The complete system fully combines the existing process characteristics of the hazardous waste incineration line, effectively solves the problem of low-cost concentration and reduction of high-salt wastewater, has the advantages of low operation cost, small occupied area, easy expansion, and not easy to be blocked compared with the conventional high-salt wastewater treatment system, and has a broad application prospect in the field of hazardous waste incineration high-salt wastewater treatment.

[0026] Specifically, the present application effectively utilizes the steam of the waste heat boiler connected with the hazardous waste incineration system, and the steam is introduced into the wastewater flash evaporation system for wastewater heating. The desalted water preparation system associated with the hazardous waste incineration system and the high-salt wastewater produced by the deacidification tower are subjected to flash evaporation concentration in the wastewater flash evaporation system. The high-salt concentrated water after flash evaporation is introduced into the concentration tower and the salt discharge system for concentration and solid-phase crystallization salt discharge. Preferably, the condensed water produced by the wastewater flash evaporation system can supplement the process water consumption of the quenching tower, thereby reducing the comprehensive water consumption of the hazardous waste incineration system. Through effective combination with the related process lines and devices of the hazardous waste incineration system, the present application effectively treats the high-salt wastewater produced by the hazardous waste incineration. The complete system has low energy consumption and obvious water-saving benefits. The complete system can perform deep concentration treatment on the high-salt wastewater, finally produce part of fresh water and crystalline salt, and realize zero discharge of high-salt wastewater.

[0027] In addition, in the system of the present application, the high-temperature flue gas of the hazardous waste incineration system is introduced into the concentration tower and the salt discharge system after being treated by the dust remover before entering the deacidification tower. On the one hand, the concentration tower and the salt discharge system can heat the concentrated wastewater by the waste heat of the high-temperature flue gas at the outlet of the dust remover, thereby reducing the energy consumption of the concentration tower. On the other hand, the flue gas can also be cooled by the concentration tower, thereby significantly reducing the evaporation amount of the slurry in the subsequent deacidification tower, effectively reducing the water consumption of the deacidification tower, and reducing the water consumption of the hazardous waste incineration system.

[0028] Further, the present application provides a multi-stage wastewater flash evaporation system in multiple effects in series. The wastewater flash evaporation system of the present application includes a multi-stage flash evaporator and a multi-stage condenser. The flash evaporation process occurs in a flash tank, thereby overcoming the problem of fouling of the heat exchange wall surface that easily occurs in the conventional evaporation process of high-salt wastewater. The wastewater flash evaporation system of the present application fully utilizes the secondary steam waste heat generated by each stage of the flash evaporator, thereby realizing step-by-step heating of the circulating wastewater, and significantly reducing the energy consumption of the system. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a schematic diagram of the system composition and connection of the present application;

[0030] Figure 2 It is a structure schematic diagram of the wastewater flash evaporation system of an embodiment of the present application;

[0031] Figure 3 It is a structure schematic diagram of the flash evaporator of an embodiment of the present application;

[0032] Figure 4 The structure diagram of the condenser of an embodiment of the present application;

[0033] Figure 5 The structure diagram of the condenser of an embodiment of the present application;

[0034] In the figure, 1 is a hazardous waste incineration system, 2 is a desalted water preparation system, 3 is a waste heat boiler, 4 is a quenching tower, 5 is a dust collector, 6 is a condensation tower and salt discharge system, 7 is a deacidification tower, 8 is a high-salinity wastewater storage tank, 9 is a wastewater flash evaporation system, and 10 is a chimney.

[0035] 901 is a steam heater, 902 is a first-stage flash evaporator, 903 is a first-stage condenser, 904 is a vacuum pump, 905 is a first-stage non-condensable gas control valve, 906 is a first-stage condensate water control valve, 907 is a first-stage wastewater outlet control valve, 908 is an n-2-stage flash evaporator, 909 is an n-2-stage condenser, 910 is an n-2-stage non-condensable gas control valve, 911 is an n-2-stage condensate water control valve, 912 is an n-2-stage wastewater outlet control valve, 913 is an n-1-stage flash evaporator, 914 is an n-1-stage condenser, 915 is an n-1-stage non-condensable gas control valve, 916 is an n-1-stage condensate water control valve, 917 is an n-1-stage wastewater outlet control valve, 918 is an n-stage flash evaporator, 919 is an n-stage condenser, 920 is an n-stage non-condensable gas control valve, 921 is an n-stage condensate water control valve, 922 is an n-stage wastewater outlet control valve, 923 is a wastewater circulating pump, 924 is a wastewater discharge pump, 925 is a fresh water storage tank, and 926 is a fresh water discharge pump.

[0036] 601 is a flushing spray layer, 602 is a demister layer, 603 is a circulating spray layer, 604 is a slurry circulating pump, 605 is an electric agitator, 606 is a slurry discharge pump, 607 is a centrifuge, 608 is a thickener, and 609 is a condensation tower.

[0037] 902-1 is a flash evaporator wastewater inlet, 902-2 is a steam outlet, and 902-3 is a flash evaporator wastewater outlet.

[0038] 903-1 is a condenser wastewater outlet, 903-2 is a steam inlet, 903-3 is a condenser wastewater inlet, 903-4 is a non-condensable gas outlet, and 903-5 is a condensate water outlet. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be described in detail below in combination with the drawings and specific embodiments.

[0040] The hazardous waste incineration high-salinity wastewater waste heat flash evaporation condensation system of the present application, such as Figure 1As shown, the system comprises a hazardous waste incineration system 1, a desalted water preparation system 2, a high-salinity wastewater storage tank 8, a waste heat boiler 3, a quench tower 4, a deacidification tower 7, a dust collector 5 and a chimney 10, and further comprises a concentration tower and salt discharge system 6 and a wastewater flash system 9.

[0041] The desalted water preparation system 2 refers to a desalination process section connected to the hazardous waste incineration system and used for treating high-salinity wastewater generated by the hazardous waste incineration system. For example, the system can use a RO reverse osmosis membrane process. The concentrated salt water generated after treatment is used as the high-salinity wastewater to be treated and is discharged into the high-salinity wastewater storage tank 8 for subsequent treatment. The treated fresh water, i.e., desalted water, can be used as boiler process water and saturated steam can be generated in the waste heat boiler 3.

[0042] For the flue gas of the hazardous waste incineration system, the hazardous waste incineration system 1 is sequentially connected to the waste heat boiler 3, the quench tower 4, the dust collector 5, the concentration tower and salt discharge system 6, and the deacidification tower 7, so that the flue gas sequentially flows through them and is discharged from the chimney 10.

[0043] During the process, the flue gas generated by the hazardous waste incineration system sequentially enters the waste heat boiler 3 to recover heat, enters the quench tower 4 to cool down, enters the dust collector 5 to remove dust, enters the concentration tower and salt discharge system 6 to contact and exchange heat with the high-salinity concentrated water in the concentration tower and salt discharge system 6, enters the deacidification tower 7 to remove acid, and is then discharged to the outside atmosphere through the chimney 10.

[0044] The concentrated salt water of the desalted water preparation system 2 and the high-salinity wastewater of the deacidification tower 7 are respectively connected to the high-salinity wastewater storage tank 8, so that the concentrated salt water of the desalted water preparation system 2 and the high-salinity wastewater generated by the deacidification tower 7 are respectively discharged into the high-salinity wastewater storage tank 8. The waste heat boiler 3 is connected to the wastewater flash system 9, so that the steam generated by the waste heat boiler 3 is discharged into the wastewater flash system 9. The high-salinity wastewater storage tank 8 is connected to the wastewater flash system 9, so that the high-salinity wastewater in the high-salinity wastewater storage tank 8 is discharged into the wastewater flash system 9. The wastewater flash system 9 is connected to the concentration tower and salt discharge system 6, so that the high-salinity concentrated water after being flashed is discharged into the concentration tower and salt discharge system 6. In the concentration tower and salt discharge system 6, the high-salinity concentrated water is further concentrated and solid-liquid separated, and the solid-phase crystalline salt is discharged.

[0045] As a preferred scheme of the present application, further, in the system, the desalted water preparation system 2 is connected to the waste heat boiler 3, so that the desalted water is discharged into the waste heat boiler 3 as boiler water. The wastewater flash system 9 is connected to the quench tower 4, so that the condensed water generated by the wastewater flash system 9 is discharged into the quench tower 4, realizing the reuse of the condensed water.

[0046] The high-salt wastewater generated by the hazardous waste incineration system of the present application is first sent to a wastewater flash evaporation system for concentration pretreatment, the concentrated water generated is sent to a concentration tower and a salt discharge system, and finally crystalline salt is obtained, and the fresh water generated by the system is sent to a quench tower as process water. Further, the complete system fully combines the existing process characteristics of the hazardous waste incineration line, effectively solves the problem of low-cost concentration and reduction of high-salt wastewater, has the advantages of low operating cost, small occupied area, easy expansion, and not easy to block, etc. compared with conventional high-salt wastewater treatment systems, and has a broad application prospect in the field of hazardous waste incineration high-salt wastewater treatment.

[0047] For the wastewater flash evaporation system, as a preferred scheme of the present application, the wastewater flash evaporation system comprises multiple-stage series-connected flash evaporators and condensers. In the multiple-stage flash evaporators, a negative pressure environment is created by utilizing the principle that the boiling point of water decreases with the decrease of ambient pressure, so that the low-temperature wastewater is flash evaporated in the system step by step, and negative pressure steam flows into the condensers for heating of the low-temperature working medium of the next stage, thereby realizing efficient and step-by-step recovery of the waste heat of high-salt wastewater.

[0048] As shown in the specific scheme, Figure 2 The wastewater flash evaporation system 9 comprises a steam heater 901 connected with the waste heat boiler 3, n-stage flash evaporators, and n-stage condensers, wherein n is an integer greater than or equal to 1.

[0049] As shown in the specific scheme, Figure 3 Each stage of the flash evaporator is provided with a steam outlet 902-2, a flash evaporator wastewater inlet 902-1 and a flash evaporator wastewater outlet 902-3, and the inside is an empty tower structure.

[0050] As shown in the specific scheme, Figure 4 Each stage of the condenser is provided with a condenser wastewater outlet 903-1, a steam inlet 903-2, a condenser wastewater inlet 903-3, a non-condensable gas outlet 903-4 and a condensate water outlet 903-5. Among them, the steam outlet of each stage of the flash evaporator is connected with the steam inlet of the same stage of the condenser. Each stage of the condenser is a shell-and-tube condenser, the tube side of the condenser is high-salt wastewater, and the shell side is steam. The n-stage condenser is connected with circulating cooling water.

[0051] The wastewater outlet of the first-stage condenser 903, the steam heater 901, the first-stage flash evaporator 902, the second-stage flash evaporator, the n-2-stage flash evaporator 908, the n-1-stage flash evaporator 913, the n-stage flash evaporator 918, the n-1-stage condenser 914, the n-2-stage condenser 909, the second-stage condenser, and the wastewater inlet of the first-stage condenser 903 are connected in sequence, and the high-salt wastewater flows into the steam heater 901 from the wastewater outlet of the first-stage condenser 903, and then enters the first-stage flash evaporator 902, thereby forming a circulating loop of the high-salt wastewater.

[0052] In the aforementioned high-salinity wastewater circulation loop, one description starting from the first-stage condenser 903 is as follows: the high-salinity wastewater is discharged from the wastewater outlet of the first-stage condenser 903 and enters the steam heater 901, where it is heated by steam. Then, the high-temperature, high-salinity wastewater flows sequentially through flash evaporators 1 to n. After multiple flash evaporations, the high-salinity wastewater is concentrated stage by stage. After concentration, it flows from the wastewater outlet of the nth-stage flash evaporator 918 into the n-1 to 1st-stage condensers to recover residual heat. Finally, it flows out from the first-stage condenser again, is heated by steam, and enters each stage of flash evaporators sequentially again, thus continuously circulating and concentrating the wastewater.

[0053] Furthermore, the wastewater outlet of the nth-stage flash evaporator 918 is connected to the thickening tower and salt outlet system 6, allowing some of the wastewater in the circulation loop to be discharged from the wastewater outlet of the nth-stage flash evaporator 918 and enter the thickening tower and salt outlet system 6 for further concentration and solid-liquid separation, discharging solid-phase crystalline salt. On the other hand, in the thickening tower and salt outlet system 6, a portion of the high-salt concentrated water from the circulation loop comes into gas-liquid contact with the flue gas from the dust collector 5 within the tower. This utilizes the high-temperature flue gas waste heat to heat the concentrated wastewater, reducing the energy consumption of the thickening tower; it also allows the flue gas to be cooled by passing through the thickening tower, significantly reducing the evaporation of slurry in the subsequent deacidification tower and reducing the water consumption of the hazardous waste incineration system.

[0054] In addition, the condenser wastewater inlet of the n-1 stage condenser 914 is connected to the high-salt wastewater storage tank 8, so that the high-salt wastewater in the high-salt wastewater storage tank 8 is added to the above-mentioned flash evaporation cycle system for concentration.

[0055] As a further aspect of the present invention, a condensate control valve is provided at the condensate outlet of each stage of the condenser. For example... Figure 2 In one embodiment presented in the figure, the condensate control valves at the condensate outlets of the first-stage condenser, the (n-2)th-stage condenser, the (n-1)th-stage condenser, and the nth-stage condenser are respectively the first-stage condensate control valve 906, the (n-2)th-stage condensate control valve 911, the (n-1)th-stage condensate control valve 916, and the nth-stage condensate control valve 921.

[0056] As a further aspect of the present invention, a non-condensable gas control valve is provided at the non-condensable gas outlet of each stage of the condenser. The non-condensable gas control valves for the first stage condenser, the (n-2)th stage condenser, the (n-1)th stage condenser, and the nth stage condenser are respectively the first stage non-condensable gas control valve 905, the (n-2)th stage non-condensable gas control valve 910, the (n-1)th stage non-condensable gas control valve 915, and the nth stage non-condensable gas control valve 920.

[0057] As a further aspect of the present application, the condensate outlet of each stage condenser is connected to a fresh water storage tank 925, which is connected to the quench tower 4 or other water consuming end, so that the condensate in the flash condenser can be reused. Further, the fresh water storage tank 925 is connected to the fresh water storage tank 925 through a fresh water discharge pump 926. The non-condensable gas outlet of the condenser is connected to a vacuum pump 904 for continuously extracting the non-condensable gas in each stage condenser, so as to maintain the negative pressure state of the waste water flash system 9, and to ensure the normal and stable operation of the system.

[0058] As a further aspect of the present application, a waste water outlet control valve is arranged between the waste water outlet of each stage flash evaporator and the waste water inlet of the next stage flash evaporator. Figure 2 As can be seen, the first stage waste water outlet control valve 907 is arranged at the waste water outlet of the first stage flash evaporator; the n-2 stage waste water outlet control valve 912 is arranged at the waste water outlet of the n-2 stage flash evaporator; the n-1 stage waste water outlet control valve 917 is arranged at the waste water outlet of the n-1 stage flash evaporator; and the n stage waste water outlet control valve 922 is arranged at the waste water outlet of the n stage flash evaporator.

[0059] The waste water outlet of the n stage flash evaporator is connected to the condenser waste water inlet of the n-1 stage condenser through a waste water circulating pump 923, and is connected to the concentration tower and the salt discharge system 6 through a waste water discharge pump 924.

[0060] As a preferred aspect of the present application, the n is 1-15, and can also be 1-5, 6-10, 11-15 or 4-8.

[0061] As a preferred aspect of the present application, the stages of flash evaporators are vertically connected in series, so that the high-salt waste water can enter the next stage flash evaporator under the action of gravity; the residual salt water in the previous stage flash evaporator enters the next stage flash evaporator through gravity and pressure difference; and the high-salt waste water after flash evaporation is subjected to counterflow heat exchange through each stage condenser. Preferably, the circulating cooling water of the n stage condenser is introduced from the top and discharged from the bottom, i.e. the n stage condenser cooling water inlet (i.e. the condenser waste water outlet) is connected to the incoming cooling water supply main pipe, and the n stage condenser cooling water outlet (i.e. the condenser waste water inlet) is connected to the incoming cooling water return main pipe.

[0062] As a preferred aspect of the present application, as shown in Fig. 1, the n stage condenser is connected to the n-1 stage condenser through a condenser waste water outlet control valve 901, and is connected to the n+1 stage condenser through a condenser waste water inlet control valve 902. Figure 5As shown, the concentration tower and salt outlet system 6 comprises a concentration tower 609, which is provided with a flushing spray layer 601, a demister layer 602 and a circulating spray layer 603 from top to bottom, and a high-salinity wastewater slurry at the bottom of the concentration tower; the top of the concentration tower 609 is provided with a wastewater inlet connected with the flushing spray layer 601, and the wastewater inlet is connected with the flashed high-salinity concentrated water from the wastewater flash system 9; the high-salinity concentrated water here refers to the high-salinity wastewater discharged from the wastewater outlet of the nth flash evaporator 918 of the wastewater flash system 9. The side of the concentration tower 609 is provided with a flue gas inlet connected with the flue gas outlet of the dust collector 5, and the flue gas inlet is arranged below the circulating spray layer 603; the top of the concentration tower 609 is provided with a flue gas outlet connected with the flue gas inlet of the deacidification tower 7; the high-salinity wastewater slurry is connected with the circulating spray layer 603 through a slurry circulating pump 604; the bottom of the concentration tower 609 is provided with a slurry discharge outlet connected with a thick solid-liquid separation device to obtain solid-phase crystalline salt. The thick solid-liquid separation device is used to further form a high-concentration slurry precipitate from the concentrated slurry, and finally separate the precipitate to obtain solid-phase crystalline salt.

[0063] As a preferred scheme of the present application, further, the thick solid-liquid separation device comprises a thickener 608 and a centrifuge 607, the thickener 608 comprises a high-salinity concentrated water inlet, a mother liquor outlet and a precipitate outlet, and the centrifuge 607 comprises a centrifuge inlet, a solid-phase discharge outlet and a supernatant discharge outlet; the high-salinity concentrated water inlet is connected with the slurry discharge outlet, the precipitate outlet is connected with the centrifuge inlet, and the solid-phase discharge outlet is used to discharge solid-phase crystalline salt; the supernatant discharge outlet and the mother liquor outlet are both connected with the high-salinity wastewater slurry in the concentration tower 609. Further preferably, an electric agitator 605 can be arranged at the bottom of the concentration tower 609 to form a strong disturbance at the bottom of the concentration tower 609, thereby reducing the blockage of the inlet and outlet. The saturated brine enters the high-salinity concentrated water inlet of the thickener 608 from the slurry discharge outlet of the concentration tower, and then the separated clear liquid is returned to the concentration tower 609 from the mother liquor outlet of the thickener 608 for re-concentration, the precipitate obtained from the thickener 608 is sent to the centrifuge 607 through the precipitate outlet and the centrifuge inlet for dehydration, the supernatant obtained from the centrifuge 607 is sent to the concentration tower 608 through the supernatant discharge outlet for re-concentration, and the precipitate obtained from the centrifuge 607 is the crystalline salt, which is discharged from the solid-phase discharge outlet and can be disposed according to its properties.

[0064] The above system can treat high-salinity wastewater with TDS of 20000-80000 mg / L and salt content of about 1-15%. The solid crystalline salt can be obtained after the high-salinity wastewater is treated by the system, the concentration ratio of the high-salinity wastewater is 2-15, and the produced fresh water can be used for the quenching tower 4 of the incineration system or other process water in the plant.

[0065] The method for treating high-salinity wastewater by using the high-salinity wastewater flash evaporation and concentration system of the hazardous waste incineration system comprises the following steps:

[0066] The flue gas generated by the hazardous waste incineration system 1 is sequentially introduced into the waste heat boiler 3 to recover heat, introduced into the quench tower 4 to reduce temperature, introduced into the dust collector 5 to remove dust, introduced into the concentration tower and salt discharge system 6 to contact and exchange heat with the high-salinity concentrated water in the concentration tower and salt discharge system 6, introduced into the deacidification tower 7 to remove acid, and then discharged to the outside atmosphere through the chimney 10. The concentrated salt water generated by the desalted water preparation system 2 and the high-salinity wastewater generated by the deacidification tower 7 are concentrated in the high-salinity wastewater storage tank 8, and the high-salinity wastewater in the high-salinity wastewater storage tank 8 is introduced into the wastewater flash evaporation system 9 for concentration. The waste heat boiler 3 generates steam by using the flue gas waste heat of the hazardous waste incineration system 1 and introduces the steam into the wastewater flash evaporation system 9, and the steam is used to heat the high-salinity wastewater to be flashed. The heated high-salinity wastewater to be flashed is flashed in the wastewater flash evaporation system 9, and the high-salinity concentrated water after flashing is introduced into the concentration and salt discharge system for further concentration and solid-liquid separation, and the solid crystalline salt is discharged.

[0067] During the process, some preferred schemes include that the condensed water generated by the wastewater flash evaporation system 9 is introduced into the quench tower 4 as process makeup water, and the desalted water separated by the desalted water preparation system is introduced into the waste heat boiler 3 as clean water as boiler water.

[0068] In combination with the above various preferred schemes, the use method and operation process of the high-salinity wastewater flash evaporation and concentration system of the hazardous waste incineration system are as follows:

[0069] S1: The 165-240℃ saturated steam generated by the waste heat boiler 3 is introduced into the steam heater 901 to heat the high-salinity wastewater to a high temperature of 110℃ or above.

[0070] S2: Then, the high-temperature high-salinity wastewater is introduced into the multi-stage flash evaporator and reduced to 45-55℃ after multi-stage flashing. In the wastewater flash evaporation system, the secondary steam of each stage is introduced from the flash evaporator and sent to the condenser as a circulating wastewater heating heat source.

[0071] S3: The condensed water generated by the multi-stage condenser is collected and sent to the quench tower 4 as process makeup water or used for other purposes. The flash evaporation and temperature reduction range of each flash evaporator is 12-18℃; the high-salinity wastewater after multi-stage flashing is mixed with the high-salinity wastewater makeup from the high-salinity wastewater storage tank 8, and the mixed high-salinity wastewater absorbs the flash evaporation heat brought by the secondary steam of each flash evaporator in the multi-stage condenser in turn, and then introduced into the steam heater 901 again to heat after being heated to a certain temperature by the multi-stage condenser, so as to realize the circulating flashing.

[0072] S4: Then, the high-salinity concentrated water generated by the wastewater flash evaporation system 9 is discharged to the concentration tower and salt discharge system 6 through the wastewater discharge pump 924, and at the same time, the high-salinity wastewater is supplemented to the wastewater flash evaporation system 9 through the high-salinity wastewater storage tank 8 to maintain the system working medium balance.

[0073] S5: A vacuum pump 904 is arranged at the end of the wastewater flash evaporation system 9 to continuously extract the non-condensable gas in each condenser to maintain the negative pressure state of the wastewater flash evaporation system 9, so as to ensure the normal and stable operation of the system.

[0074] S6: Then, the high-salt concentrated water discharged from the wastewater flash evaporation system 9 is sent to the concentration tower and salt discharge system 6, enters the concentration tower 609 from the flushing spray layer 601, directly contacts with the flue gas outlet of the dust remover 5, and is further concentrated by using the waste heat of the flue gas. A slurry circulating pump 604 is arranged at the bottom of the concentration tower 609, and the slurry at the bottom of the concentration tower 609 is sent to the circulating spray layer 603 to be fully heat-exchanged and concentrated with the flue gas.

[0075] S7: Then, the saturated concentrated water is sent to the thickener 608 for further separation by a slurry discharge pump 606, and the mixed flue gas is sent to the deacidification tower 7 for further treatment after being demisted by the demister layer 602.

[0076] S8: An electric agitator 605 is arranged at the bottom of the concentration tower 609 to form a strong disturbance at the bottom of the concentration tower 609, so as to reduce the blockage of the inlet and outlet. After the saturated brine enters the thickener 608, the separated clear liquid is sent to the concentration tower 609 for re-concentration, the obtained precipitate of the thickener 608 is sent to the centrifuge 607 for dehydration, the supernatant obtained from the centrifuge 607 is sent to the concentration tower 608 for re-concentration, and the obtained precipitate from the centrifuge 607 is the crystallized salt, which can be treated and disposed according to its properties.

[0077] From the above scheme, the present application has the following characteristics and advantages:

[0078] The complete system fully combines the existing process characteristics of the hazardous waste incineration line, effectively solves the problems of low-cost concentration and reduction of high-salt wastewater, and is a comprehensive system effectively combining the related process devices of the high-salt wastewater treatment system and the hazardous waste incineration system.

[0079] 1) The complete system has low energy consumption and obvious water-saving benefits, and can realize zero discharge of high-salt wastewater. Specifically, in terms of heat consumption, the system only consumes a small amount of existing hazardous waste incineration line waste heat boiler steam, the wastewater flash evaporation system mainly relies on the secondary steam generated by the wastewater cascade flash evaporation of each flash evaporator to realize wastewater heating, and the concentration tower and salt discharge system mainly relies on the waste heat of the high-temperature flue gas outlet of the dust remover of the hazardous waste incineration system to heat the concentrated wastewater. The heat of the complete system is repeatedly utilized in multiple stages, the thermal efficiency is high, the system operation cost is low, and the system has good energy-saving and emission-reducing effects. In terms of water consumption, the flue gas can significantly reduce the evaporation amount of the slurry in the deacidification tower after being cooled by the concentration tower and salt discharge system, effectively reducing the water supplement amount of the deacidification tower and reducing the water consumption of the incineration system. At the same time, the produced fresh water can supplement the process water consumption of the quenching tower, and reduce the comprehensive water consumption of the incineration system.

[0080] 2) Achieve zero discharge of high-salt wastewater. The complete system can deeply concentrate the high-salt wastewater, finally produce part of fresh water and crystalline salt, no secondary wastewater discharge, and the fresh water can be used for quenching tower section water supplement.

[0081] 3) A multi-stage wastewater flash evaporation system is developed. The multi-stage wastewater flash evaporation system fully utilizes the secondary steam waste heat generated by each stage of flash evaporator to realize the step-by-step heating of the circulating wastewater. In some specific embodiments, the heat consumption of the system per ton of wastewater treatment of the present application is only 1 / 4-1 / 3 of that of single-effect evaporation, and the high-salt wastewater circulation of the system mainly relies on the gravity flow of the wastewater, and only one circulating pump needs to be set in the complete system, and the power consumption per ton of wastewater of the system is about 1 / 3 of that of conventional multi-effect evaporation.

[0082] 4) A high-ratio concentration tower and salt discharge system are developed. High-temperature flue gas and high-salt concentrated water discharged from the dust collector of the incineration system enter the high-ratio concentration tower, the high-salt concentrated water is directly contacted with the high-temperature flue gas in the high-ratio concentration tower, the high-salt concentrated water can be instantaneously cooled to 70-80℃, and the flue gas and the water vapor evaporated in the tank are discharged through the top of the concentration tower. By controlling the circulation times of the slurry, the high-salt concentrated water can be directly concentrated and crystallized in the concentration tower. The salt water slurry in the tower can be sent to the crystalline salt separation system through the slurry discharge pump to obtain dry finished product mixed salt, and the mother liquor is returned to the concentration tower for recycling.

[0083] Example 1

[0084] The following is a specific analysis of a 70t / h hazardous waste disposal line producing 2t / h high-salt wastewater, with the system configuration using a flash evaporation module and a concentration tower module.

[0085] 1. Incineration line scale: 70t / h;

[0086] 2. Wet standard square flue gas volume after dust collector of incineration line: 20000Nm 3 / h;

[0087] 3. Flue gas temperature: 160℃;

[0088] 4. Wastewater treatment scale: 2t / h;

[0089] 5. Salt content: 10%;

[0090] 6. System salt output: 0.2t / h;

[0091] 7. System fresh water production: 1t / h;

[0092] 8. Flash evaporation module:

[0093] 1) Water inflow: 2t / h;

[0094] 2) Concentrated water outflow: 1t / h;

[0095] 3) Concentration ratio: 2 times;

[0096] 4) Number of stages: 4 stages;

[0097] 5) Inlet water temperature of each stage: 110°C, 95°C, 80°C, 65°C;

[0098] 6) Tank temperature of each stage: 95°C, 80°C, 65°C, 50°C;

[0099] 7) Tank pressure of each stage (absolute pressure): 84.6 kPa, 47.4 kPa, 25.0 kPa, 12.4 kPa;

[0100] 8) Enthalpy of wastewater in each stage: 398 kJ / kg; 335 kJ / kg; 272 kJ / kg; 209 kJ / kg;

[0101] 9) Evaporated water amount of each stage: 253 kg / h; 246 kg / h; 239 kg / h; 233 kg / h;

[0102] 10) Circulation ratio in the tank: 10 times;

[0103] 11) Circulating water amount: 20 t / h;

[0104] 12) Steam consumption: 446 kg / h;

[0105] 9. Concentration tower and salt discharge system:

[0106] 1) Inlet water amount: 1 t / h;

[0107] 2) Inlet water salt concentration: 20%;

[0108] 3) Salt discharge amount: 0.2 t / h;

[0109] 4) Slurry circulation amount: 20 t / h;

[0110] 5) Spray layer number: 2 layers;

[0111] 6) Concentration tower outlet flue gas temperature: 76.5°C;

[0112] Example 2

[0113] The following is a specific analysis of a 100 t / h hazardous waste disposal line producing 3 t / h of salt-containing wastewater, with a system configuration using a flash module and a concentration tower module:

[0114] 1. Incineration line scale: 80 t / h;

[0115] 2. Wet standard flue gas volume after the dust collector of the incineration line: 32000 Nm 3 / h;

[0116] 3. Flue gas temperature: 165°C;

[0117] 4. Wastewater treatment scale: 3 t / h;

[0118] 5. Salt content: 8%;

[0119] 6. System salt output: 0.24 t / h;

[0120] 7. System freshwater production: 1.5 t / h;

[0121] 8. Flash module:

[0122] 1) Influent: 3 t / h;

[0123] 2) Concentrated water effluent: 1.5 t / h;

[0124] 3) Concentration ratio: 2 times;

[0125] 4) Number of stages: 4 stages;

[0126] 5) Influent temperature at each stage: 110°C, 95°C, 80°C, 65°C;

[0127] 6) Tank internal temperature at each stage: 95°C, 80°C, 65°C, 50°C;

[0128] 7) Tank internal pressure (absolute pressure) at each stage: 84.6 kPa, 47.4 kPa, 25.0 kPa, 12.4 kPa;

[0129] 8) Enthalpy of wastewater in each tank: 398 kJ / kg; 335 kJ / kg; 272 kJ / kg; 209 kJ / kg;

[0130] 9) Evaporated water at each stage: 379.5 kg / h; 369 kg / h; 358.5 kg / h; 349.5 kg / h;

[0131] 10) Tank internal circulation ratio: 10 times;

[0132] 11) Circulating water usage: 30 t / h;

[0133] 12) Steam consumption: 669 kg / h;

[0134] 9. Concentration tower and salt discharge system:

[0135] 1) Influent: 1.5 t / h;

[0136] 2) Influent salt concentration: 16%;

[0137] 3) Salt output: 0.24 t / h;

[0138] 4) Slurry circulation: 32 t / h;

[0139] 5) Spray layer: 2 layers;

[0140] 6) Concentration tower outlet flue gas temperature: 77.5℃;

[0141] The present application is described in detail above with reference to specific embodiments and exemplary examples, but these descriptions are not to be understood as limiting the present application. It is understood by a person skilled in the art that various equivalent substitutions, modifications or improvements can be made to the technical solutions of the present application and the embodiments thereof without departing from the spirit and scope of the present application, and these all fall within the scope of the present application.

Claims

1. A hazardous waste incineration high-salinity wastewater waste heat flash evaporation concentration system, comprising a hazardous waste incineration system, a desalted water preparation system, a high-salinity wastewater storage tank, a waste heat boiler, a quench tower, a deacidification tower, a dust remover and a chimney, characterized in that, The waste incineration system further comprises a concentration tower and a salt discharge system, a waste water flash system; the waste incineration system is sequentially connected with a waste heat boiler, a quenching tower, a dust remover, the concentration tower and the salt discharge system, a deacidification tower and a chimney, so that the flue gas flows through the waste heat boiler, the quenching tower, the dust remover, the concentration tower and the salt discharge system, the deacidification tower and the chimney in sequence and is discharged from the chimney; desalted water of the desalted water preparation system is communicated with the waste heat boiler; concentrated salt water of the desalted water preparation system and high-salinity waste water of the deacidification tower are respectively communicated with a high-salinity waste water storage tank; steam of the waste heat boiler is connected with the waste water flash system; the high-salinity waste water storage tank is connected with the waste water flash system; the waste water flash system is connected with the concentration tower and the salt discharge system; condensed water of the waste water flash system is connected with the quenching tower. The waste water flash system comprises a steam heater connected with the waste heat boiler, n-stage flash evaporators and n-stage condensers, wherein n is an integer greater than or equal to 3; each stage of the flash evaporators is provided with a steam outlet, a flash evaporator waste water inlet and a flash evaporator waste water outlet; each stage of the condensers is provided with a steam inlet, a condenser waste water inlet, a condenser waste water outlet, a non-condensed gas outlet and a condensed water outlet; each stage of the condensers is a tubular condenser, the tube side of the condenser is high-salinity waste water, and the shell side is steam; the steam outlet of each stage of the flash evaporators is connected with the steam inlet of the same stage of the condensers; the steam heater, the first-stage to the n-stage flash evaporators, the n-1-stage condenser, the n-2-stage to the first-stage condensers and the steam heater are sequentially connected to form a circulating loop of the high-salinity waste water; the flash evaporator waste water outlet of the n-stage flash evaporator is connected with the concentration tower and the salt discharge system; the condenser waste water inlet of the n-1-stage condenser is connected with the high-salinity waste water storage tank; the n-stage condenser is connected with circulating cooling water.

2. The hazardous waste incineration high-salinity wastewater waste heat flash evaporation concentration system according to claim 1, characterized in that, The condensed water outlet of each stage of the condensers is provided with a condensed water control valve; the non-condensed gas outlet of each stage of the condensers is provided with a non-condensed gas control valve; the condensed water outlet is connected with a fresh water storage tank, and the fresh water storage tank is connected with the quenching tower or other water consuming ends; the non-condensed gas outlet of the condenser is connected with a vacuum pump through the non-condensed gas control valve.

3. The hazardous waste incineration high-salinity wastewater waste heat flash evaporation concentration system according to claim 1, characterized in that, The flash evaporator waste water outlet of each stage of the flash evaporators is provided with a waste water outlet control valve between the flash evaporator waste water outlet of each stage of the flash evaporators and the flash evaporator waste water inlet of the next stage of the flash evaporators; the flash evaporator waste water outlet of the n-stage flash evaporator is connected with the condenser waste water inlet of the n-1-stage condenser through a waste water circulating pump and is connected with the concentration tower and the salt discharge system through a waste water discharge pump.

4. The hazardous waste incineration high-salinity wastewater waste heat flash evaporation concentration system according to claim 1, characterized in that, The n is 3 to 15.

5. The hazardous waste incineration high-salinity wastewater waste heat flash evaporation concentration system according to claim 1, characterized in that, The high-salinity waste water can enter the next stage of the flash evaporators under the action of gravity through vertical series communication between the flash evaporators; the n-stage condenser is connected with circulating cooling water in an up-in and down-out mode.

6. The hazardous waste incineration high-salinity wastewater waste heat flash evaporation concentration system according to claim 1, characterized in that, The concentration tower and salt discharging system comprises a concentration tower, wherein a flushing spray layer, a demister layer and a circulating spray layer are arranged from top to bottom in the concentration tower, and a high-salinity wastewater slurry is arranged at the bottom of the concentration tower; a wastewater inlet connected with the flushing spray layer is arranged at the top of the concentration tower, and the wastewater inlet is connected with the high-salinity concentrated water after flashing from a wastewater flashing system; a flue gas inlet connected with a flue gas outlet of a dust collector is arranged on the concentration tower, and the flue gas inlet is arranged below the circulating spray layer; a flue gas outlet is arranged at the top of the concentration tower, and the flue gas outlet is connected with a flue gas inlet of a deacidification tower; the high-salinity wastewater slurry is connected with the circulating spray layer through a slurry circulating pump; a slurry discharge outlet is arranged at the bottom of the concentration tower, and the slurry discharge outlet is connected with a thick solid-liquid separation device to obtain a solid-phase crystalline salt.

7. A method for treating high-salinity wastewater by using the hazardous waste incineration high-salinity wastewater waste heat flashing and concentrating system according to any one of claims 1-6, characterized in that: The flue gas generated by the hazardous waste incineration system enters a waste heat boiler in sequence to recover heat, enters a quenching tower to cool, enters a dust collector to remove dust, enters the concentration tower and salt discharging system to contact and exchange heat with the high-salinity concentrated water in the concentration tower and salt discharging system, enters a deacidification tower to remove acid, and is then discharged to the outside atmosphere through a chimney; The concentrated brine generated by the desalted water preparation system and the high-salinity wastewater generated by the deacidification tower are concentrated in a high-salinity wastewater storage tank, and the high-salinity wastewater in the high-salinity wastewater storage tank is introduced into a wastewater flashing system to be flashed; The waste heat boiler generates steam by using the flue gas waste heat of the hazardous waste incineration system to enter the wastewater flashing system to heat the high-salinity wastewater to be flashed; The high-salinity wastewater after being heated is flashed in the wastewater flashing system, the high-salinity concentrated water after being flashed is introduced into the concentration and salt discharging system for further concentration and solid-liquid separation, and the solid-phase crystalline salt is discharged; and the condensed water generated by the wastewater flashing system is introduced into the quenching tower as process makeup water.

8. The method of claim 7, wherein, The steam generated by the waste heat boiler is saturated steam at 165-240 DEG C, the temperature of the high-salinity wastewater to be flashed after being heated is greater than or equal to 110 DEG C, and the temperature of the high-salinity wastewater after being flashed by the wastewater flashing system is 45-55 DEG C; the wastewater flashing system comprises multiple flash evaporators connected in series, and the flashing and cooling range of each flash evaporator is 12-18 DEG C; the TDS of the high-salinity wastewater to be treated by the hazardous waste incineration high-salinity wastewater waste heat flashing and concentrating system is 20000-80000 mg / L, and the salt content is 1-15%.

9. A method for treating high-salinity wastewater using the hazardous waste incineration high-salinity wastewater flash evaporation concentration system according to any one of claims 1-6, characterized in that, The method comprises the following steps: S1: the 165-240 DEG C saturated steam generated by the waste heat boiler enters a steam heater to heat the high-salinity wastewater in the wastewater flashing system to a high temperature of more than 110 DEG C; S2: the high-temperature high-salinity wastewater enters multiple flash evaporators and is reduced to 45-55 DEG C after multiple flashing; in the wastewater flashing system, the secondary steam of each stage is introduced from the flash evaporator and sent to a condenser as a heating heat source for the circulating high-salinity wastewater; The condensed water generated by the multiple condensers is collected and sent to the quenching tower as process makeup water or introduced into other water end; The flash cooling range of each stage of flash evaporator is 12-18℃; after the high-salinity wastewater from the multi-stage flash evaporation is mixed with the high-salinity wastewater from the high-salinity wastewater storage tank, the mixed high-salinity wastewater absorbs the flash heat brought by the secondary steam of each stage of flash evaporator in the multi-stage condenser in turn, and then enters the steam heater again for heat compensation after the heat exchange in the multi-stage condenser, so as to realize the cycle flash evaporation; S3: The high-salinity concentrated water generated by the wastewater flash evaporation system is discharged to the concentration tower and salt discharge system through a wastewater discharge pump, and at the same time, the wastewater flash evaporation system is supplemented with water through the high-salinity wastewater storage tank to maintain the working medium balance of the system; a vacuum pump is arranged at the end of the wastewater flash evaporation system to continuously extract the non-condensable gas in each stage of condenser to maintain the negative pressure state of the wastewater flash evaporation system to ensure the normal and stable operation of the system; S4: The high-salinity concentrated water discharged from the wastewater flash evaporation system is sent to the concentration tower and salt discharge system for further concentration and solid-liquid separation to discharge the solid-phase crystalline salt; in the process, the flue gas discharged from the dust collector is introduced into the concentration tower and salt discharge system to make the flue gas directly contact with the high-salinity concentrated water to further concentrate the high-salinity concentrated water through the waste heat of the flue gas.

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