Integrated grading flash evaporation deep heat recovery device for high-salt, high-scale and high-corrosion slurry

Abstract

The utility model discloses an integrated grading flash evaporation deep heat recovery device for high-salt, high-scale and high-corrosion slurry, and belongs to the technical field of industrial energy conservation and desulfurization slurry waste heat heat supply. According to the integrated equipment, in order to solve the problems that due to graded flash evaporation and graded heat removal, the final-stage vacuumizing difficulty is too large, equipment assemblies are too many, the occupied area is too large, the manufacturing cost is too high, and operation and maintenance are difficult, flash evaporation tanks are combined into an integral graded flash evaporation tank, and a flash evaporation steam heater is combined into an integral graded heater; furthermore, all the components are combined into an integrated tank body, and all functional areas are separated by adopting partition plates. A first-stage special micro-differential pressure vacuum pump is added, and non-condensable gas of the last-stage heater is pumped out and sent to an inlet of the previous-stage heater or a conventional vacuum pump; alkaline water is sprayed to a space, where non-condensable gas is enriched, of a final-stage heater to absorb SO2 and reduce partial pressure, so that the temperature of a concentrated slurry outlet and the smoke exhaust temperature of a final-stage flash tank can be greatly reduced. The device is suitable for the fields of coal-fired boilers, sintering machines and industrial kilns requiring waste heat recovery.

Description

Technical Field

[0001] The utility model relates to an integrated fractional flash evaporation deep heat recovery device for high-salt, high-scale and high-corrosion slurry, belonging to the technical fields of industrial energy conservation and waste heat heating of desulfurization slurry. Background Art

[0002] In many coal-fired process kilns such as coal-fired boilers, sintering machines in steel mills, and cement kilns, a large amount of high-sulfur, high-dust and highly polluting high-temperature flue gas is discharged during the heat production process. Recovering the waste heat of the flue gas can not only reduce the system heat loss, but also reduce the fuel consumption and emissions of pollutants such as greenhouse gases, and improve the thermal efficiency of the entire high-energy-consuming factory production line. In recent years, a method of recovering the waste heat of flue gas by desulfurization slurry flash evaporation + absorption heat pump has emerged, that is, the heat in the flue gas is taken out from the desulfurization slurry through a flash tank, and the flash steam is sent to the heat pump for waste heat recovery, and the return water of the heat network or other process water is heated, while the concentrated liquid returns to the desulfurization circulating water. Its advantages are: there is no need to transform the flue gas system, reducing the on-site implementation difficulty; the quality of the condensed water is good, which is convenient for recycling. However, the disadvantages are also very obvious: the flue gas temperature can usually only be reduced to 42-45°C, recovering about half of the waste heat of the flue gas, which does not belong to deep heat recovery and can only be regarded as a half-finished project. There is still a large amount of flue gas waste heat escaping from the flue gas, and secondary transformation is still needed in the future to achieve deep heat recovery.

[0003] The cost of calculating the unit waste heat recovery of the desulfurization slurry flash evaporation heat recovery system is relatively high, and the investment payback period is long. The fundamental reason why it cannot reduce the flue gas temperature to the 30°C level and achieve deep heat recovery is: firstly, the desulfurization slurry flash evaporation complete set of equipment is a vacuum equipment, its system integration is relatively complex, the guarantee requirements are high, and the lower the flash steam temperature, the larger the specific volume, the larger the equipment volume, and the higher the cost; secondly, more non-condensable gases such as SO2 will escape during the desulfurization slurry flash evaporation process. The flash steam is sent to the absorption heat pump, and it is difficult to evacuate during the condensation heat release process in the horizontal evaporator of the heat pump. The absolute pressure during actual operation can only be maintained at about 7-8 kPa. It is very difficult to further improve the vacuum degree with the existing equipment and conditions, and it is impossible to further improve the vacuum degree like a normal condenser. Therefore, the saturation temperature of the flash steam can only be reduced to the 38-40°C level, resulting in the flue gas temperature can only be reduced to the 40-45°C level. Summary of the Utility Model

[0004] The object and task of the present utility model are as follows. Aiming at the problems of excessive difficulty in final-stage vacuum extraction, excessive number of equipment components, excessive floor area, excessive cost, and difficulties in operation, maintenance, and repair brought about by staged flash evaporation and staged heat extraction, the flash tanks are combined into an integral staged flash tank, and the flash steam heaters are combined into an integral staged heater. Furthermore, all components are combined into an integrated housing, and each functional area is separated by a partition, thus constructing a brand-new integrated device for staged flash evaporation and staged heat extraction of desulfurization slurry.

[0005] The specific description of the present utility model is as follows: An integrated staged flash evaporation deep heat recovery device for high-salt, high-scale, and high-corrosion slurry, which is composed of N-stage flash tanks, N-stage flash steam heaters, and connecting pipelines and components, where N is greater than or equal to 2. It is characterized in that the N-stage flash tanks share a flash tank body 1. The flash tank body 1 is divided into N-stage flash evaporation areas from top to bottom and arranged in series. The upper first stage is a pre-stage flash tank 21, and the Nth stage is a final-stage flash tank 31. Flash evaporation partitions 31a are provided between the flash evaporation areas; the N-stage flash steam heaters share a flash steam heater body 2. The flash steam heater body 2 is divided into N-stage condensation heat exchange areas from top to bottom and arranged in series. The upper first stage is a pre-stage heater 26, and the Nth stage is a final-stage heater 36. Heating area partitions 31c are provided between the condensation heat exchange areas; among them, the slurry inlet of the pre-stage flash tank 21 is communicated with the incoming material pipe of the original slurry T1, the slurry outlet of the pre-stage flash tank 21 is connected to the slurry inlet of the final-stage flash tank 31 through a slurry downcomer 31b, and the slurry outlet of the final-stage flash tank 31 is communicated with the outgoing material pipe of the concentrated slurry T2; the steam inlet of the pre-stage heater 26 is connected to the flash steam outlet of the pre-stage flash tank 21 through a pre-stage connecting pipe 25, the low-temperature water inlet of the pre-stage heater 26 is communicated with the incoming water pipe of the heat network return water H1, the low-temperature water outlet of the pre-stage heater 26 is communicated with the return water pipe of the heat network return water H2, and the condensate outlet of the pre-stage heater 26 is connected to the inlet of the final-stage condensate pump 37; the steam inlet of the final-stage heater 36 is connected to the flash steam outlet of the final-stage flash tank 31 through a final-stage connecting pipe 35, the low-temperature water inlet of the final-stage heater 36 is communicated with the incoming water pipe of the low-temperature process water C1, the low-temperature water outlet of the final-stage heater 36 is communicated with the return water pipe of the low-temperature process water C2, the condensate outlet of the final-stage heater 36 is connected to the inlet of the final-stage condensate pump 37, and the outlet of the final-stage condensate pump 37 is connected to the outgoing water pipe of the final-stage externally discharged condensate W2.

[0006] The flash tank body 1 and the flash steam heater body 2 are set as an integrated slurry multi-stage flash waste heat recovery tank body 3, which is internally divided into two parts: a flash zone 3a and a condensation heat exchange zone 3b, separated by a partition in the middle. There is a front-stage through-flow port 25a opened on the partition between the flash steam outlet of the front-stage flash tank (21) and the steam inlet of the front-stage heater 26, and a final-stage through-flow port 35a opened on the partition between the flash steam outlet of the final-stage flash tank 31 and the steam inlet of the final-stage heater 36; the slurry multi-stage flash waste heat recovery tank body 3 adopts a cylindrical or square structure and a vertical or horizontal structure.

[0007] The front-stage heater 26 and the final-stage heater 36 respectively adopt a vertical tube-and-shell heat exchange structure, with a condensate hot well provided at the bottom, and a non-condensable gas discharge port provided above the hot well liquid level. The outlet of the non-condensable gas above the bottom hot well liquid level of the final-stage heater 36 is connected to the intake port of the micro differential pressure vacuum pump 38, and the exhaust port of the micro differential pressure vacuum pump 38 is connected to the intake port of the vacuum pump 18 and the outlet of the front-stage non-condensable gas S above the condensate of the bottom hot well of the front-stage heater 26.

[0008] The internal heat exchange elements of the final-stage heater 36 and the space above the bottom hot well liquid level are for non-condensable gas disposal, where an alkali liquid spraying device 36a and a waterproof non-condensable gas suction device 36b are provided. A hot well liquid level measurement and control component 36c is also provided inside and outside the hot well. The upper part of the alkali liquid spraying device 36a is an area with non-condensable gas S1 containing more SO2, and the area above the condensate liquid level of the hot well is an area with non-condensable gas S2 containing less SO2. The condensate outlet of the final-stage heater 36 is connected to the inlet of the final-stage condensate pump 37, and the outlet of the final-stage condensate pump 37 is respectively connected to the outlet of the alkali addition pump 30 and the inlet of the alkali liquid spraying device 36a, and is also connected to the outlet pipe of the final-stage external discharge condensate W2. The inlet of the alkali addition pump 30 is connected to the feed pipe of the sodium hydroxide solution Na; the outlet of the waterproof non-condensable gas suction device 36b is connected to the intake port of the micro differential pressure vacuum pump 38, and the exhaust port of the micro differential pressure vacuum pump 38 is connected to the inlet of the front-stage connection pipe 25 or the front-stage through-flow port 25a and the inlet of the front-stage heater 26 through the first switching valve 38a, and is connected to the inlet of the vacuum pump 18 and the outlet of the front-stage non-condensable gas S above the condensate of the bottom hot well of the front-stage heater 26 through the second switching valve 38b. The exhaust port of the vacuum pump 18 is connected to the discharge pipe of the mixed non-condensable gas S3.

[0009] The alkali liquid spraying device 36a adopts a nozzle-type empty tower structure or a packing structure.

[0010] The mass concentration range of sodium hydroxide in the sodium hydroxide solution Na is 0% to 60%.

[0011] The outlet pipe of the final-stage external discharge condensate W2 is connected to the inlet of the make-up water pipe of the return water H1 from the heat network.

[0012] The beneficial effects of the present utility model are as follows.

[0013] (1) Heat is extracted from the desulfurization slurry by means of staged flash evaporation. The flash steam with lower pressure and temperature generated by the last-stage flash tank is preferentially used to heat process water at lower temperatures, such as make-up demineralized water, heat network make-up water, low-temperature intermediate water for the first-stage preheating of the boiler inlet air, or low-temperature heat source water of an absorption heat pump, low-temperature heat source water of a compression heat pump, and other low-temperature process water. The flash steam with higher temperature generated by the front-stage flash tank can be used for the secondary heating of the above-mentioned low-temperature process water or for heating process water at higher temperatures such as heat network return water.

[0014] (2) The flash tanks at all levels are combined into one and arranged in a flash tank body; the flash steam heaters at all levels are combined into one and arranged in a flash steam heater body. If conditions permit on-site, the above two tank bodies can be further combined into one to form an integrated multi-stage flash heat recovery tank body for slurry. Such an integrated tank body can realize the functions of staged flash evaporation of the entire slurry and / or staged heat exchange of flash steam. The structural layout of the entire equipment system is extremely compact, the components are simplified, the occupied space is greatly reduced, the material consumption is reduced, the equipment and installation cost are reduced, the operation, maintenance, and repair are simplified, and the operation and maintenance costs are reduced.

[0015] (3) The vacuum degree of the space where the non-condensable gas is located at the lower part of the last-stage heater 36 is required to be higher, for example, the absolute pressure reaches the level of 2-4 kPa. The control methods and measures to achieve such a high vacuum degree include: chemically absorbing or physically absorbing components such as SO2 in the non-condensable gas by using sodium hydroxide alkaline solution, thereby greatly reducing the content of non-condensable gas and significantly increasing the vacuum degree; on this basis, a micro differential pressure vacuum pump 38 is used to extract the remaining non-condensable gas and send it to the inlet of the heater (26) or the inlet of the vacuum pump 18, thereby greatly reducing the pressure of the non-condensable gas at the lower part of the last-stage heater, greatly increasing the vacuum degree of the last-stage flash tank 31, greatly reducing the temperature of its concentrated slurry outlet, and further greatly reducing the flue gas temperature, so as to achieve the maximum recovery of flue gas waste heat.

[0016] (4) The equipment capacity and the required input power of the micro differential pressure vacuum pump 38 are much smaller than those of the conventional vacuum pumping method, reducing energy consumption, initial investment, and operation costs.

[0017] (5) The vacuum degrees of the flash tanks - heaters at all levels of this solution can be separately and real-time adjusted according to the changes in the inlet and outlet temperatures of the water to be heated by each of them and the operating conditions of the entire system, so as to better realize the system operation control, reduce the system energy consumption, and improve the comprehensive energy-saving benefit and economic benefit.

[0018] (6) This solution can be widely applied to the fields of waste heat recovery required for coal-fired boilers, sintering machines, and industrial furnaces. Description of the Drawings

[0019] Figure 1 is the system schematic diagram of Specific Embodiment 1 of the present utility model, Figure 2 is the system schematic diagram of Specific Embodiment 2 of the present utility model, Figure 3 is the system schematic diagram of Specific Embodiment 3 of the present utility model, Figure 4 is the system schematic diagram of Specific Embodiment 4 of the present utility model.

[0020] Figure 1 and 2 , 3, and 4, the component numbers and names are as follows.

[0021] Flash tank body 1, flash steam heater body 2, slurry multi-stage flash waste heat recovery tank body 3, flash evaporation area 3a, condensation heat exchange area 3b, vacuum pump 18, pre-flash tank 21, pre-connection pipe 25, pre-flow port 25a, pre-heater 26, alkali addition pump 30, final flash tank 31, flash partition 31a, slurry downcomer 31b, heating area partition 31c, final connection pipe 35, final flow port 35a, final heater 36, alkali liquid spraying device 36a, waterproof non-condensable gas suction device 36b, hot well liquid level measurement and control component 36c, final condensate pump 37, differential pressure vacuum pump 38, first switching valve 38a, second switching valve 38b, low-temperature process water incoming water C1, low-temperature process water outgoing water C2, heat network return water incoming water H1, heat network return water outgoing water H2, sodium hydroxide solution Na, pre-non-condensable gas S, SO2-rich non-condensable gas S1, SO2-poor non-condensable gas S2, mixed non-condensable gas S3, original slurry T1, concentrated slurry T2, final external discharged condensate W2. Specific Embodiments

[0022] Figure 1 is the system schematic diagram of Specific Embodiment 1 of the present utility model, Figure 2 is the system schematic diagram of Specific Embodiment 2 of the present utility model, Figure 3 is the system schematic diagram of Specific Embodiment 3 of the present utility model, Figure 4 is the system schematic diagram of Specific Embodiment 4 of the present utility model.

[0023] Specific Embodiment 1 of the present utility model is as follows. Refer to Figure 1As shown in the figure. An integrated staged flash evaporation deep heat recovery device for high-salt, high-scale, and high-corrosion slurry is composed of N flash evaporation tanks, N flash steam heaters, and connecting pipelines and components, where N is greater than or equal to 2. It is characterized in that the N flash evaporation tanks share a flash evaporation tank body 1. The flash evaporation tank body 1 is divided into N flash evaporation zones from top to bottom and arranged in series. The upper first stage is the preflash evaporation tank 21, and the Nth stage is the final flash evaporation tank 31. Flash evaporation partition plates 31a are arranged between the flash evaporation zones; the N flash steam heaters share a flash steam heater body 2. The flash steam heater body 2 is divided into N condensation heat exchange zones from top to bottom and arranged in series. The upper first stage is the preheater 26, and the Nth stage is the final heater 36. Heating zone partition plates 31c are arranged between the condensation heat exchange zones; among them, the slurry inlet of the preflash evaporation tank 21 is communicated with the incoming material pipe of the original slurry T1, the slurry outlet of the preflash evaporation tank 21 is connected to the slurry inlet of the final flash evaporation tank 31 through a slurry downcomer 31b, and the slurry outlet of the final flash evaporation tank 31 is communicated with the outgoing material pipe of the concentrated slurry T2; the steam inlet of the preheater 26 is connected to the flash steam outlet of the preflash evaporation tank 21 through a pre-connection pipe 25, the low-temperature water inlet of the preheater 26 is communicated with the incoming water pipe of the heat network return water H1, the low-temperature water outlet of the preheater 26 is communicated with the outgoing water pipe of the heat network return water H2, and the condensate outlet of the preheater 26 is connected to the inlet of the final condensate pump 37; the steam inlet of the final heater 36 is connected to the flash steam outlet of the final flash evaporation tank 31 through a final connection pipe 35, the low-temperature water inlet of the final heater 36 is communicated with the incoming water pipe of the low-temperature process water C1, the low-temperature water outlet of the final heater 36 is communicated with the outgoing water pipe of the low-temperature process water C2, the condensate outlet of the final heater 36 is connected to the inlet of the final condensate pump 37, and the outlet of the final condensate pump 37 is communicated with the outgoing water pipe of the final external discharged condensate W2.

[0024] The internal heat exchange element of the last-stage heater 36 and the space above the liquid level of the bottom hot well are for non-condensable gas disposal, in which an alkali liquor spraying device 36a and a waterproof non-condensable gas suction device 36b are provided. Inside and outside the hot well, a hot well liquid level measurement and control assembly 36c is also provided. The upper part of the alkali liquor spraying device 36a is the area with non-condensable gas S1 containing more SO2, and the area above the condensate water liquid level of the hot well is the area with non-condensable gas S2 containing less SO2. The condensate water outlet of the last-stage heater 36 is connected to the inlet of the last-stage condensate pump 37. The outlet of the last-stage condensate pump 37 is respectively connected to the outlet of the alkali adding pump 30 and the inlet of the alkali liquor spraying device 36a, and is communicated with the outlet pipe of the last-stage discharged condensate water W2. The inlet of the alkali adding pump 30 is communicated with the feed pipe of the sodium hydroxide solution Na; the outlet of the waterproof non-condensable gas suction device 36b is connected to the inlet of the differential pressure vacuum pump 38. The exhaust port of the differential pressure vacuum pump 38 is connected to the inlet of the pre-connected pipe 25 or the pre-flow port 25a and the inlet of the pre-heater 26 through the first switching valve 38a, and is communicated with the inlet of the vacuum pump 18 and the outlet of the pre-non-condensable gas S above the condensate water liquid level at the bottom of the pre-heater 26 through the second switching valve 38b. The exhaust port of the vacuum pump 18 is communicated with the discharge pipe of the mixed non-condensable gas S3.

[0025] The alkali liquor spraying device 36a adopts a nozzle-type empty tower structure or a packing structure.

[0026] The mass concentration range of sodium hydroxide in the sodium hydroxide solution Na is 0% to 60%.

[0027] The outlet pipe of the last-stage discharged condensate water W2 is communicated with the inlet of the make-up water pipe of the return water H1 of the heat network.

[0028] The specific embodiment 2 of the present utility model is as follows. Refer to Figure 2 as shown. The specific embodiment 2 is only different from the specific embodiment 1 in the following parts, and the rest are the same: The flash tank body 1 and the flash steam heater body 2 are set as an integrated slurry multi-stage flash heat recovery tank body 3, which is internally divided into two parts: a flash zone 3a and a condensation heat exchange zone 3b, separated by a partition in the middle. A pre-flow port 25a is opened on the partition between the flash steam outlet of the pre-flash tank (21) and the steam inlet of the pre-heater 26, and a last-stage flow port 35a is opened on the partition between the flash steam outlet of the last-stage flash tank 31 and the steam inlet of the last-stage heater 36; The slurry multi-stage flash heat recovery tank body 3 adopts a cylindrical or square structure and can adopt a vertical or horizontal structure.

[0029] The specific embodiment 3 of the present utility model is as follows. Refer to Figure 3As shown in the figure. Specific Embodiment 3 is only different from Specific Embodiment 1 in the following parts, and the rest are the same: The preheater 26 and the final-stage heater 36 respectively adopt a vertical shell-and-tube heat exchange structure, with a condensate hot well provided at the bottom, and a non-condensable gas discharge port provided above the liquid level of the hot well. Among them, the outlet of the non-condensable gas above the liquid level of the bottom hot well of the final-stage heater 36 is connected to the inlet of the differential pressure vacuum pump 38, and the exhaust port of the differential pressure vacuum pump 38 is communicated with the inlet of the vacuum pump 18 and the outlet of the pre-non-condensable gas S above the condensate liquid level of the bottom hot well of the preheater 26.

[0030] The specific embodiment 4 of the present invention is as follows. Refer to Figure 4 As shown in the figure. Specific Embodiment 4 is only different from Specific Embodiment 2 in the following parts, and the rest are the same: The preheater 26 and the final-stage heater 36 respectively adopt a vertical shell-and-tube heat exchange structure, with a condensate hot well provided at the bottom, and a non-condensable gas discharge port provided above the liquid level of the hot well. Among them, the outlet of the non-condensable gas above the liquid level of the bottom hot well of the final-stage heater 36 is connected to the inlet of the differential pressure vacuum pump 38, and the exhaust port of the differential pressure vacuum pump 38 is communicated with the inlet of the vacuum pump 18 and the outlet of the pre-non-condensable gas S above the condensate liquid level of the bottom hot well of the preheater 26.

[0031] It should be noted that the present invention realizes heat recovery based on the multi-stage flash evaporation and condensation heat exchange of desulfurization slurry, adopts an integrated structure to combine each flash tank into one, combines each flash steam heater into one, and combines the former two into an integrated device when conditions are appropriate, and adopts key technologies such as comprehensively controlling the vacuum degree inside each heater, and proposes a complete set of brand-new integrated systems and operation strategies for the flash evaporation of desulfurization slurry to recover the waste heat of flue gas in depth. According to this overall solution, there can be different specific implementation measures and specific implementation devices with different structures. The above specific implementation manners are only one of them. Any other similar simple deformed implementation manners, such as simple deformations of flash steam and heat exchangers and simple adjustments of pipelines, or simple changes in the vacuum pumping method, etc., all fall within the protection scope of the present invention.

Claims

1. An integrated graded flash deep heat recovery device for high-salt, high-scale and high-corrosion slurry, consisting of N-stage flash tanks, N-stage flash steam heaters and connecting pipelines and components, wherein N is greater than or equal to 2, characterized in that: The N-stage flash tanks share a flash tank body (1), the flash tank body (1) is divided into N-stage flash zones from top to bottom, arranged in series, wherein the first stage at the top is a front flash tank (21), the N-th stage is a final flash tank (31), and flash baffles (31a) are provided between the flash zones; the N-stage flash steam heaters share a flash steam heater body (2), the flash steam heater body (2) is divided into N-stage condensation heat exchange zones from top to bottom, arranged in series, wherein the first stage at the top is a front flash tank (21), the N-th stage is a final flash tank (31), and flash baffles (31a) are provided between the flash zones. The first stage is a preheater (26), the Nth stage is a final stage heater (36), and a heating zone partition (31c) is provided between each condensation heat exchange zone; wherein the slurry inlet of the pre-flash tank (21) is connected to the feed pipe of the original slurry (T1), the slurry outlet of the pre-flash tank (21) is connected to the slurry inlet of the final stage flash tank (31) through the slurry down pipe (31b), and the slurry outlet of the final stage flash tank (31) is connected to the discharge pipe of the concentrated slurry (T2); the pre-flash tank (21) is connected to the feed pipe of the original slurry (T1), and the slurry outlet of the final stage flash tank (31) is connected to the discharge pipe of the concentrated slurry (T2); The steam inlet of the preheater (26) is connected to the flash steam outlet of the pre-flash tank (21) through the pre-connecting pipe (25); the low-temperature water inlet of the preheater (26) is connected to the water inlet pipe of the heat network return water (H1); the low-temperature water outlet of the preheater (26) is connected to the water return pipe of the heat network return water (H2); the condensate outlet of the preheater (26) is connected to the inlet of the final-stage condensate pump (37); the steam inlet of the final-stage heater (36) is connected to the water inlet pipe of the heat network return water (H1); the low-temperature water outlet of the preheater (26) is connected to the water return pipe of the heat network return water (H2); and the condensate outlet of the preheater (26) is connected to the inlet of the final-stage condensate pump (37). The final-stage connecting pipe (35) is connected to the flash steam outlet of the final-stage flash tank (31); the low-temperature water inlet of the final-stage heater (36) is connected to the water inlet pipe of the low-temperature process water (C1); the low-temperature water outlet of the final-stage heater (36) is connected to the water return pipe of the low-temperature process water return (C2); the condensate water outlet of the final-stage heater (36) is connected to the inlet of the final-stage condensate pump (37); and the outlet of the final-stage condensate pump (37) is connected to the water outlet pipe of the final-stage condensate water (W2).

2. The integrated graded flash evaporation deep heat recovery device for high-salt, high-scale and high-corrosion slurry according to claim 1 is characterized in that The flash tank body (1) and the flash steam heater body (2) are configured as an integrated slurry multi-stage flash evaporation waste heat recovery tank body (3), wherein the interior is divided into two parts, namely a flash evaporation zone (3a) and a condensation heat exchange zone (3b), separated by a partition plate in the middle, wherein a front flow opening (25a) is provided on the partition plate between the flash steam outlet of the front flash tank (21) and the steam inlet of the front heater (26), and a final flow opening (35a) is provided on the partition plate between the flash steam outlet of the final flash tank (31) and the steam inlet of the final heater (36); the slurry multi-stage flash evaporation waste heat recovery tank body (3) adopts a cylindrical or square structure, and adopts a vertical or horizontal structure.

3. The integrated graded flash evaporation deep heat recovery device for high-salt, high-scale and high-corrosion slurry according to claim 1 is characterized in that The pre-heater (26) and the final heater (36) respectively adopt a vertical shell-and-tube heat exchange structure, a condensate hot well is arranged at the bottom, and a non-condensable gas discharge port is arranged above the hot well liquid surface, wherein the outlet of the non-condensable gas above the hot well liquid surface at the bottom of the final heater (36) is connected to the air inlet of the micro-pressure difference vacuum pump (38), and the exhaust port of the micro-pressure difference vacuum pump (38) is connected to the air inlet of the vacuum pump (18) and the outlet of the pre-condensable gas (S) above the condensate liquid surface of the hot well at the bottom of the pre-heater (26).

4. The integrated graded flash evaporation deep heat recovery device for high-salt, high-scale and high-corrosion slurry as claimed in claim 3 is characterized in that The internal heat exchange element of the final stage heater (36) and the space above the bottom hot well liquid level form a non-condensable gas disposal space, wherein an alkali solution spraying device (36a) and a waterproof non-condensable gas suction device (36b) are provided, and hot well liquid level measurement and control components (36c) are also provided inside and outside the hot well, wherein the upper part of the alkali solution spraying device (36a) is a region containing more SO2 non-condensable gas (S1), and the region above the hot well condensate water level is a region containing less SO2 non-condensable gas (S2), the condensate water outlet of the final stage heater (36) is connected to the inlet of the final stage condensate pump (37), and the outlet of the final stage condensate pump (37) is respectively connected to the outlet of the alkali adding pump (30) and the inlet of the alkali solution spraying device (36a), and The device is connected to the outlet pipe of the final stage condensate (W2), and the inlet of the alkali pump (30) is connected to the feed pipe of the sodium hydroxide solution (Na); the outlet of the waterproof non-condensable gas suction device (36b) is connected to the air inlet of the micro-pressure difference vacuum pump (38); the exhaust port of the micro-pressure difference vacuum pump (38) is connected to the inlet of the front connecting pipe (25) or the front flow port (25a) and the front heater (26) through the first switch valve (38a), and is connected to the inlet of the vacuum pump (18) and the outlet of the front non-condensable gas (S) on the condensate liquid surface of the bottom hot well of the front heater (26) through the second switch valve (38b); the exhaust port of the vacuum pump (18) is connected to the discharge pipe of the mixed non-condensable gas (S3).

5. The integrated graded flash evaporation deep heat recovery device for high-salt, high-scale and high-corrosion slurry according to claim 4 is characterized in that The alkali solution spraying device (36a) adopts a nozzle-type empty tower structure or a filler structure.

6. The integrated graded flash evaporation deep heat recovery device for high-salt, high-scale and high-corrosion slurry according to claim 4 is characterized in that The sodium hydroxide mass concentration of the sodium hydroxide solution (Na) is in the range of 0% to 60%.

7. The integrated graded flash evaporation deep heat recovery device for high-salt, high-scale and high-corrosion slurry according to claim 1 is characterized in that The outlet pipe of the final-stage condensate (W2) is connected to the inlet of the water supply pipe of the return water (H1) of the heating network.

Images