Household garbage power plant fly ash salt treatment and separation system

Abstract

The utility model discloses a household garbage power plant fly ash salt treatment and separation system. Comprising a plasma electric arc furnace, a secondary combustion chamber, a waste heat utilization boiler, a primary desulfurization and desalination water scrubber, a secondary desulfurization and desalination water scrubber, a neutralization desulfurization treatment device, a pressed cake separation device, a cooling tower, a membrane treatment device, a sodium chloride crystallization device, a sodium salt centrifugation device, a sodium salt drying device, a sodium salt packaging device, a potassium chloride crystallization device and a potassium salt centrifugation device. A potassium salt drying device, a potassium salt packaging device, a mother liquor drying device and a carnallite packaging device. According to the utility model, the salt is separated from the fly ash, so that the collected crystallized salt is high in purity, the water consumption is greatly reduced, the energy consumption and the environmental pollution are reduced by adopting a spray cooling and salt dissolving mode, the salt of the fly ash can be fully washed, and the water consumption is reduced. And the salt separated from the flue gas is crystallized after being neutralized, flocculated and subjected to reverse osmosis, and is separated into high-purity potassium chloride and sodium chloride industrial salt.

Description

TECHNICAL FIELD

[0001] The utility model belongs to waste gas treatment technical field, concretely relates to a kind of fly ash salt fraction treatment separation system of domestic waste power plant. BACKGROUND

[0002] At present, the flue gas generated by garbage power generation contains more fly ash, and the flue gas composition is relatively complex, containing a large amount of salt, a small amount of combustible gas (CO, H2, CH4, VOC, NOx gas, etc.), trace amounts of dioxin and heavy metals, etc. In the process of resource utilization, a large amount of water is often used to wash the fly ash comprehensively. Fly ash washing is to dissolve and extract potassium, sodium and chlorine in fly ash to produce secondary industrial products. The fly ash after washing (also known as dechlorinated fly ash) is sent to a cement kiln for high-temperature calcination to solidify and decompose heavy metals and dioxin in the cement kiln. This fly ash washing method has the following problems: first, the water consumption is huge, causing waste of water resources, high energy consumption, large amount of subsequent wastewater treatment and great pollution to the environment; second, the water dissolves the salt in the fly ash and also dissolves other harmful substances into the water. If the salt is further evaporated and crystallized, there will be a large amount of impurities in the crystallized salt, which cannot be utilized due to too many impurities. SUMMARY

[0003] To solve the above technical problems in the prior art, the utility model provides a fly ash salt fraction treatment separation system for domestic waste power plant with less water consumption, low energy consumption, no pollution and high salt crystallization purity.

[0004] To solve the above technical problems, the utility model adopts the following technical scheme: a fly ash salt fraction treatment separation system for domestic waste power plant, comprising a plasma arc furnace, a secondary combustion chamber, a waste heat utilization boiler, a primary desulfurization and desalination water washing tower, a secondary desulfurization and desalination water washing tower, a neutralization desulfurization treatment device, a cake separation device, a cooling tower, a membrane treatment device, a sodium chloride crystallization device, a sodium salt centrifugal device, a sodium salt drying device, a sodium salt packaging device, a potassium chloride crystallization device, a potassium salt centrifugal device, a potassium salt drying device, a potassium salt packaging device, a mother liquor drying device and a salt packaging device.

[0005] The smoke outlet of the plasma arc furnace is connected with the smoke inlet of the secondary combustion chamber, the smoke outlet of the secondary combustion chamber is connected with the smoke gas inlet of the waste heat utilization boiler, the smoke gas outlet of the waste heat utilization boiler is connected with the smoke inlet of the primary desulfurization and desalination water washing tower, the smoke outlet of the primary desulfurization and desalination water washing tower is connected with the smoke inlet of the secondary desulfurization and desalination water washing tower, and the smoke outlet of the secondary desulfurization and desalination water washing tower is connected with a smoke purification system.

[0006] The water outlet of the first desulfurization and desalination water washing tower and the second desulfurization and desalination water washing tower is connected with the water inlet of the neutral desulfurization treatment device, the sludge outlet after precipitation of the neutral desulfurization treatment device is connected with the inlet of the cake separation device, the liquid in the neutral desulfurization treatment device is circulated and cooled through the cooling tower, the liquid outlet of the neutral desulfurization treatment device is connected with the liquid inlet of the membrane treatment device, the concentrated liquid outlet of the membrane treatment device is connected with the liquid inlet of the sodium chloride crystallization device, the discharge outlet of the sodium chloride crystallization device is connected with the sodium salt centrifugal device, the sodium salt drying device and the sodium salt packaging device in sequence, the liquid outlet of the sodium chloride crystallization device is connected with the liquid inlet of the potassium chloride crystallization device, the discharge outlet of the potassium chloride crystallization device is connected with the potassium salt centrifugal device, the potassium salt drying device and the potassium salt packaging device in sequence, and the liquid outlet of the potassium chloride crystallization device is connected with the liquid inlet of the mother liquor drying device, and the discharge outlet of the mother liquor drying device is connected with the miscellaneous salt packaging device.

[0007] The steam outlet of the waste heat utilization boiler is connected with the steam inlet of the sodium chloride crystallization device; the clean water outlet of the membrane treatment device is connected with the first spray device in the first desulfurization and desalination water washing tower and the second spray device in the second desulfurization and desalination water washing tower respectively, and the second desulfurization and desalination water washing tower is also provided with a third spray device, and the water source of the third spray device is tap water.

[0008] The inner cavity of the secondary combustion chamber is in a U-shaped structure, the left upper end of the secondary combustion chamber is provided with a gas inlet elbow joint, the right upper end of the secondary combustion chamber is provided with a gas outlet elbow joint, the right end of the gas outlet elbow joint is connected with the flue gas inlet on the left side of the waste heat utilization boiler, the waste heat utilization boiler is internally provided with a baffle heat exchange channel, and the right side of the waste heat utilization boiler is provided with a flue gas outlet;

[0009] The left upper part of the secondary combustion chamber is provided with a burner mounting port, the burner mounting port is provided with a natural gas burner, the left lower part of the secondary combustion chamber is provided with a first SNCR spray gun for horizontally spraying urea solution to the right, the spraying direction of the first SNCR spray gun is along the horizontal center line of the bottom of the U-shaped cavity, and the right lower part of the secondary combustion chamber is provided with a second SNCR spray gun for vertically spraying urea solution upward, and the spraying direction of the second SNCR spray gun is along the vertical center line of the right side of the U-shaped cavity.

[0010] The bottom of the secondary combustion chamber is provided with a first support, the inner wall of the cavity of the secondary combustion chamber is provided with a refractory castable layer, the outer part of the secondary combustion chamber is wrapped with a rock wool insulation layer, the bottom of the secondary combustion chamber is provided with a dust falling pipe at the middle position of the U-shaped structure, and the lower end of the dust falling pipe is provided with a first valve.

[0011] The waste heat boiler comprises a second support, a furnace chamber surrounded by outer membrane water cooling walls is arranged on the second support, an inner membrane water cooling wall is arranged in the middle of the furnace chamber, the upper end and the lower end of the inner membrane water cooling wall are connected with the top and the bottom of the outer membrane water cooling wall respectively, the inner membrane water cooling wall divides the furnace chamber into a left heat exchange cavity and a right heat exchange cavity, a through hole for connecting the left heat exchange cavity and the right heat exchange cavity is arranged at the lower part of the inner membrane water cooling wall, the flue gas inlet is arranged at the upper left side of the outer membrane water cooling wall, the flue gas outlet is arranged at the upper right side of the outer membrane water cooling wall, a boiler drum is arranged above the outer membrane water cooling wall, the boiler drum is connected with the top of the outer membrane water cooling wall through a steam rising pipe and a cold water falling pipe, the flue gas inlet, the left heat exchange cavity, the through hole, the right heat exchange cavity and the flue gas outlet form a through baffle heat exchange channel, and a dust hopper is arranged at the bottom of the left heat exchange cavity and the right heat exchange cavity.

[0012] The center line of the boiler drum is horizontally arranged along the left-right direction, a liquid level meter is arranged at the left end of the boiler drum, a blowdown pipe joint is arranged at the lower part of the right end of the boiler drum, a steam outlet, a safety valve interface, a safety valve standby interface and a pressure gauge interface are arranged at the top of the boiler drum, a water supply pipe joint is arranged at the upper part of the front side of the boiler drum, a water supply distribution pipe connected with the inner port of the water supply pipe joint is arranged in the boiler drum, a water supply distribution hole plate located below the water supply distribution pipe is arranged in the boiler drum, and a steam-water separator connected with the steam outlet is arranged in the upper part of the boiler drum.

[0013] Compared with the prior art, the utility model has the following technical effects:

[0014] 1) The steam rising pipe is adjacent to the steam outlet (the rising steam is easier to enter into the boiler drum), the cold water falling pipe is far away from the steam outlet. The steam-water separator is arranged at the top of the boiler drum, the steam and the water are separated by the hole plate and the baffle, the water content of the high-temperature steam is not more than 3%, and the steam quality is guaranteed. The water supply distribution pipe and the water supply distribution hole plate can guarantee that the water supply is uniformly distributed into the boiler drum, so that the temperature deviation of each part in the boiler drum is within 3 DEG C, and the steam production efficiency is improved.

[0015] 2) The secondary combustion chamber can improve the flue gas temperature, fully burn the combustible gas such as H2 and CO in the flue gas, reduce the NOx in the flue gas into N2 and CO2, and decompose dioxin. The U-shaped inner cavity structure of the secondary combustion chamber has the following advantages: it is beneficial to the balance of the flue gas temperature; it can guarantee that the flue gas and the urea solution are fully mixed, and improve the SNCR denitration efficiency; it is beneficial to fully decomposing the dioxin and the combustible gas in the flue gas; the U-shaped inner cavity wall is not easy to accumulate dust, and the bottom is provided with a dust falling pipe, so that the deposits are easily discharged.

[0016] 3) flue gas enters the waste heat utilization boiler to exchange heat, the heat of the flue gas is utilized, and the generated high-temperature steam is used for the subsequent fly ash desalting process, and meanwhile, the temperature of the flue gas is reduced after passing through the waste heat utilization boiler, thereby providing preliminary cooling for the subsequent desulfurization and desalting spraying.

[0017] 4) the hearth of the waste heat utilization boiler adopts a vertical structure, and the inside is not easy to accumulate dust and salt, and after long-time operation, the hearth is convenient to overhaul and clean; the adopted external membrane type water cooling wall structure is compact, steel material is saved, and a large amount of sealing castable and heat preservation material is reduced; the bottom is provided with a dust falling hopper, and the dust accumulated after long-time operation is convenient to clean.

[0018] 5) the utility model discloses a plasma arc furnace, which is used for treating flue gas, and is used for treating combustible gas and dioxin in the flue gas, and is used for desulfurization and desalting.

[0019] In summary, the utility model adopts the principle that gaseous salt is cooled to become liquid salt and is dissolved into water mist by spraying water mist (three-stage spraying devices in the primary desulfurization and desalting water washing tower and the secondary desulfurization and desalting water washing tower), the salt is separated from fly ash first, so that the purity of the collected crystallized salt is high, the water consumption is greatly reduced by adopting the salt dissolving mode of spraying and cooling, energy consumption and environmental pollution are reduced, the salt in fly ash is fully washed, the separated salt in flue gas is crystallized into high-purity salt after neutralization, flocculation and reverse osmosis, and the salt is used as industrial salt, the salt mainly contains sodium chloride and potassium chloride, and the salt is further separated and utilized. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a plane arrangement structure schematic view of the utility model;

[0021] Figure 2 is Figure 1 a structure schematic view of the secondary combustion chamber and the heat utilization boiler in the utility model;

[0022] Figure 3 is Figure 2 an enlarged view of the boiler drum. DETAILED DESCRIPTION

[0023] The embodiment of the utility model will be further described in detail in combination with the drawings and examples.

[0024] As Figure 1 , Figure 2 and Figure 3The utility model discloses a domestic waste power plant fly ash salt processing separation system, including plasma electric arc furnace 32, secondary combustion chamber 1, waste heat utilization boiler 33, primary desulfurization and desalination water washing tower 34, secondary desulfurization and desalination water washing tower 35, neutralization desulfurization treatment device 36, cake separation device 37, cooling tower 38, membrane processing device 39, sodium chloride crystallization device 40, sodium salt centrifugal device 41, sodium salt drying device 42, sodium salt packaging device 43, potassium chloride crystallization device 44, potassium salt centrifugal device 45, potassium salt drying device 46, potassium salt packaging device 47, mother liquor drying device 48 and miscellaneous salt packaging device 49,

[0025] The smoke outlet of the plasma electric arc furnace 32 is connected with the smoke inlet of the secondary combustion chamber 1, the smoke outlet of the secondary combustion chamber 1 is connected with the flue gas inlet of the waste heat utilization boiler 33, the flue gas outlet of the waste heat utilization boiler 33 is connected with the smoke inlet of the primary desulfurization and desalination water washing tower 34, the smoke outlet of the primary desulfurization and desalination water washing tower 34 is connected with the smoke inlet of the secondary desulfurization and desalination water washing tower 35, and the smoke outlet of the secondary desulfurization and desalination water washing tower 35 is connected with a flue gas purification system.

[0026] The water outlets of the primary desulfurization and desalination water washing tower 34 and the secondary desulfurization and desalination water washing tower 35 are connected with the water inlet of the neutralization desulfurization treatment device 36, the sludge outlet after precipitation of the neutralization desulfurization treatment device 36 is connected with the inlet of the cake separation device 37, the liquid in the neutralization desulfurization treatment device 36 is circulated and cooled through the cooling tower 38, the liquid outlet of the neutralization desulfurization treatment device 36 is connected with the liquid inlet of the membrane processing device 39, the concentrated liquid outlet of the membrane processing device 39 is connected with the liquid inlet of the sodium chloride crystallization device 40, the discharge outlet of the sodium chloride crystallization device 40 is sequentially connected with the sodium salt centrifugal device 41, the sodium salt drying device 42 and the sodium salt packaging device 43, the liquid outlet of the sodium chloride crystallization device 40 is connected with the liquid inlet of the potassium chloride crystallization device 44, the discharge outlet of the potassium chloride crystallization device 44 is sequentially connected with the potassium salt centrifugal device 45, the potassium salt drying device 46 and the potassium salt packaging device 47, the liquid outlet of the potassium chloride crystallization device 44 is connected with the liquid inlet of the mother liquor drying device 48, and the discharge outlet of the mother liquor drying device 48 is connected with the miscellaneous salt packaging device 49.

[0027] The steam outlet of the waste heat utilization boiler 33 is connected with the steam inlet of the sodium chloride crystallization device 40, the clean water outlet of the membrane processing device 39 is connected with a primary spraying device 50 in the primary desulfurization and desalination water washing tower 34 and a secondary spraying device 51 in the secondary desulfurization and desalination water washing tower 35 respectively, and a tertiary spraying device 52 is further arranged in the secondary desulfurization and desalination water washing tower 35, wherein the water source of the tertiary spraying device 52 is tap water.

[0028] The inner cavity of the secondary combustion chamber 1 is in U-shaped structure, the left upper end of the secondary combustion chamber 1 is provided with an air inlet elbow joint 2, the right upper end of the secondary combustion chamber 1 is provided with an air outlet elbow joint 3, the right end of the air outlet elbow joint 3 is connected with a flue gas inlet 4 at the left side of a waste heat utilization boiler 33, the waste heat utilization boiler 33 is internally provided with a baffle heat exchange channel, and the right side of the waste heat utilization boiler 33 is provided with a flue gas outlet 5;

[0029] The left upper part of the secondary combustion chamber 1 is provided with a burner mounting port 6, the burner mounting port 6 is internally provided with a natural gas burner 7, the left lower part of the secondary combustion chamber 1 is provided with a first SNCR spray gun 8 for horizontally spraying urea solution to the right, the spraying direction of the first SNCR spray gun 8 is along the horizontal center line of the bottom of the U-shaped cavity, and the right lower part of the secondary combustion chamber 1 is provided with a second SNCR spray gun 9 for vertically spraying urea solution upward, the spraying direction of the second SNCR spray gun 9 is along the vertical center line of the right side of the U-shaped cavity.

[0030] The bottom of the secondary combustion chamber 1 is provided with a first support 10, the inner cavity wall of the secondary combustion chamber 1 is provided with a refractory castable layer, the outer part of the secondary combustion chamber 1 is wrapped with a rock wool heat preservation layer, the bottom of the secondary combustion chamber 1 is provided with a dust falling pipe 11 at the middle position of the U-shaped structure, and the lower end of the dust falling pipe 11 is provided with a first valve.

[0031] The waste heat utilization boiler 33 comprises a second support 12, the second support 12 is provided with a hearth surrounded by an external membrane water wall 13, the hearth is provided with an internal membrane water wall 14 in the middle part, the upper end and the lower end of the internal membrane water wall 14 are connected with the top and the bottom of the external membrane water wall 13 respectively, the internal membrane water wall 14 divides the hearth into a left heat exchange cavity 15 and a right heat exchange cavity 16, the lower part of the internal membrane water wall 14 is provided with a through hole 17 communicating the left heat exchange cavity 15 and the right heat exchange cavity 16, the flue gas inlet 4 is arranged at the left upper part of the external membrane water wall 13, the flue gas outlet 5 is arranged at the right upper part of the external membrane water wall 13, the upper part of the external membrane water wall 13 is provided with a boiler drum 18, the boiler drum 18 is connected with the top of the external membrane water wall 13 through a steam rising pipe 19 and a cold water flowing pipe 20; the flue gas inlet 4, the left heat exchange cavity 15, the through hole 17, the right heat exchange cavity 16 and the flue gas outlet 5 form a through baffle heat exchange channel; the bottom of the left heat exchange cavity 15 and the right heat exchange cavity 16 are each provided with a dust falling hopper 31, and the lower end of the dust falling hopper 31 is provided with a second valve.

[0032] The center line of the boiler drum 18 is horizontally arranged along the left-right direction, the left end of the boiler drum 18 is provided with a liquid level meter 21, the lower part of the right end of the boiler drum 18 is provided with a blowdown pipe joint 22, the top of the boiler drum 18 is provided with a steam outlet 23, a safety valve interface 24, a safety valve standby interface 25 and a pressure gauge interface 26, the upper part of the front side of the boiler drum 18 is provided with a water supply pipe joint 27, the inside of the boiler drum 18 is provided with a water supply distribution pipe 28 connected with the inner port of the water supply pipe joint 27, the inside of the boiler drum 18 is provided with a water supply distribution hole plate 29 located below the water supply distribution pipe 28, and the upper part of the inside of the boiler drum 18 is provided with a steam-water separator 30 connected with the steam outlet 23.

[0033] The working method of the household garbage power plant fly ash salt treatment separation system comprises the following steps:

[0034] (1) The household garbage is first subjected to melting treatment by the plasma arc furnace 32 to remove dioxins in the fly ash;

[0035] (2) The flue gas discharged from the plasma arc furnace 32 is introduced into the secondary combustion chamber 1, the combustible gas in the flue gas is fully burned, the undecomposed dioxins are completely decomposed, and the flue gas is subjected to denitration;

[0036] (3) The high-temperature flue gas discharged from the secondary combustion chamber 1 after denitration is introduced into the waste heat utilization boiler 33 for cooling;

[0037] (4) The flue gas discharged from the waste heat utilization boiler 33 is introduced into the first-stage desulfurization and desalination water washing tower 34 and the second-stage desulfurization and desalination water washing tower 35 in turn, and is rapidly cooled and removed of salt and SO2 in the flue gas by means of three-stage water spraying; the flue gas after desulfurization and desalination is treated by the flue gas purification system and then discharged into the air;

[0038] (5) The salt-containing water settled in the first-stage desulfurization and desalination water washing tower and the second-stage desulfurization and desalination water washing tower 35 is discharged into the neutralization and desulfurization treatment device 36, and then is discharged into the membrane treatment device 39 for treatment;

[0039] (6) The high-concentration salt water is discharged into the sodium chloride crystallization device 40, the sodium salt is separated out first, then the potassium chloride crystallization device 44 is discharged into, the potassium salt is separated out, and finally the miscellaneous salt is separated out by the mother liquor drying device 48.

[0040] The specific process of step (2) is as follows: the flue gas generated by the plasma arc furnace 32 is connected with the air inlet elbow joint 2 through the flue gas discharge pipe, the flue gas enters the inner cavity of the secondary combustion chamber 1, the flame sprayed by the burner 7 increases the temperature in the secondary combustion chamber 1 to 1100℃, the combustible gas and dioxin in the flue gas are burned and decomposed at high temperature, when the flue gas passes through the lower part of the U-shaped inner cavity, the first SNCR spray gun 8 sprays atomized urea to the right, and the second SNCR spray gun 9 sprays atomized urea upward, the urea fully reacts with NOx in the flue gas as follows: 4CO(NH2)2+5NO+302→4CO2+4H2O+5N2, thereby removing NOx in the flue gas, achieving the purpose of simultaneous denitration; the dust in the flue gas falls into the ash falling pipe 11 for temporary storage.

[0041] The specific process of step (3) is as follows: the pretreated flue gas enters the waste heat utilization boiler 33, the high-temperature flue gas passes through the flue gas inlet 4, the left heat exchange cavity 15, the through hole 17, the right heat exchange cavity 16 and the flue gas outlet 5 in sequence to form a through baffle heat exchange channel, the water in the external membrane water cooling wall 13 and the internal membrane water cooling wall 14 is heated, the heated water forms steam which enters the drum 18 through the steam rising pipe 19, and then the water in the steam is separated from the steam in the steam-water separator 30 into the drum 18, and then the high-temperature steam substantially free of water is discharged through the steam outlet 23 to provide high-temperature steam for the sodium chloride crystallization device 40, so as to save energy; the normal temperature water is injected through the feed water pipe joint 27, and is first sprayed onto the feed water distribution hole plate 29 through the feed water distribution pipe 28, so as to ensure that the feed water is evenly distributed into the drum 18.

[0042] The specific process of step (4) is as follows: the 800℃ flue gas discharged from the waste heat utilization boiler 33 enters the first-stage desulfurization and desalination water washing tower 34, the first-stage spray device 50 arranged in the first-stage desulfurization and desalination water washing tower 34 rapidly reduces the temperature of the flue gas to 81℃-82℃, then the flue gas enters the second-stage desulfurization and desalination water washing tower 35, and the second-stage spray device 51 and the third-stage spray device 52 arranged in the second-stage desulfurization and desalination water washing tower 35 continuously spray the flue gas, the spray water amount of the first-stage spray device 50 and the second-stage spray device 51 are both 15t / h, and the spray water amount of the third-stage spray device 52 is 2.75t / h, the flue gas after three-stage water spraying is in a supersaturated state, the moisture content of the flue gas is 48.34%, the spray water fully absorbs and dissolves the salt and SO2 in the flue gas, and the desalination efficiency is >90%.

[0043] The specific process of step (5) is that the salt-containing water settled in the first desulfurization and desalination water washing tower 34 and the second desulfurization and desalination water washing tower 35 first enters a desulfurization treatment device, which comprises a regulating tank and a reaction tank. The salt-containing solution first enters the regulating tank to adjust the water quantity and uniform the water quality. The water out of the regulating tank is transferred to the reaction tank. Liquid alkali or soda ash is added to remove heavy metals and total hardness of calcium and magnesium. After flocculation and sedimentation, the sludge enters a cake pressing separation device 37. The cake pressing separation device 37 presses the sludge into a mud cake. The clear liquid at the upper part of the reaction tank enters a membrane treatment device 39. After being purified by the membrane treatment device 39, the liquid enters a sodium chloride crystallization device 40.

[0044] The specific process of step (6) is that the salt water is evaporated in the MVR salt crystallizer of the sodium chloride crystallization device 40 to concentrate the solute. Sodium chloride is first saturated and precipitated. The salt slurry is transferred to a sodium chloride thickener by a discharge pump to increase the solid-liquid ratio and then enters a sodium salt centrifugal device 41. The wet sodium salt after centrifugal dewatering is dried by a sodium salt drying device 42 to obtain dry sodium chloride. After being packaged by a sodium salt packaging device 43, the dry sodium chloride is temporarily stored.

[0045] The salt water after separation of sodium chloride enters a potassium chloride crystallization device 44. The MVR salt evaporator of the potassium chloride crystallization device 44 controls the concentration of potassium chloride so that potassium chloride does not precipitate in the evaporator. The mother liquor is discharged from the crystallizer and is sequentially sent to a first vacuum crystallizer and a second vacuum crystallizer to precipitate potassium chloride by vacuum cooling crystallization. The potassium chloride slurry is transferred to a potassium chloride thickener by a discharge pump to increase the solid-liquid ratio and then enters a potassium salt centrifugal device 45. The wet potassium salt after centrifugal dewatering is dried by a potassium salt drying device 46 to obtain dry potassium chloride. After being packaged by a potassium salt packaging device 47, the dry potassium chloride is temporarily stored. In order to improve the recovery rate of sodium chloride and potassium chloride, the cooling mother liquor of the sodium chloride crystallization device 40 is partially returned to the first desulfurization and desalination water washing tower 34 and the second desulfurization and desalination water washing tower 35 as spraying water for continuous circulation. The evaporation mother liquor is partially discharged to a mother liquor drying device 48 for drying treatment to obtain miscellaneous salt. Figure 2 The middle single arrow points to the direction of flue gas flow. Figure 3 The middle single arrow is the direction of water flow, and the double arrow is the direction of steam flow.

[0046] It needs to be emphasized that the plasma arc furnace 32, the burner 7, the first SNCR spray gun 8, the second SNCR spray gun 9, the liquid level meter 21, the steam-water separator 30, the valve, the first desulfurization and desalination water washing tower 34, the second desulfurization and desalination water washing tower 35, the neutralization desulfurization treatment device 36, the cake separation device 37, the cooling tower 38, the membrane treatment device 39, the sodium chloride crystallization device 40, the sodium salt centrifugal device 41, the sodium salt drying device 42, the sodium salt packaging device 43, the potassium chloride crystallization device 44, the potassium salt centrifugal device 45, the potassium salt drying device 46, the potassium salt packaging device 47, the mother liquor drying device 48 and the miscellaneous salt packaging device 49 in the utility model are all prior art, which can be purchased in the market, and the specific structure and working principle will not be repeated.

[0047] The above examples illustrate the basic principles and characteristics of the utility model, but the above only illustrates the preferred embodiments of the utility model, and is not limited by the described embodiments. Those skilled in the art can make many forms of deformation and improvement under the inspiration of the patent without departing from the purpose of the utility model and the scope protected by the claims, which all belong to the protection scope of the utility model. Therefore, the utility model patent and the protection scope should be subject to the appended claims.

Claims

1. A municipal solid waste incinerator fly ash salt fraction treatment separation system, characterized by: The system comprises a plasma arc furnace, a secondary combustion chamber, a waste heat utilization boiler, a first desulfurization and desalination water washing tower, a second desulfurization and desalination water washing tower, a neutralization desulfurization treatment device, a cake separation device, a cooling tower, a membrane treatment device, a sodium chloride crystallization device, a sodium salt centrifugal device, a sodium salt drying device, a sodium salt packaging device, a potassium chloride crystallization device, a potassium salt centrifugal device, a potassium salt drying device, a potassium salt packaging device, a mother liquor drying device and a miscellaneous salt packaging device. The exhaust port of the plasma arc furnace is connected with the smoke inlet of the secondary combustion chamber, the smoke outlet of the secondary combustion chamber is connected with the smoke gas inlet of the waste heat utilization boiler, the smoke gas outlet of the waste heat utilization boiler is connected with the smoke inlet of the first desulfurization and desalination water washing tower, the smoke outlet of the first desulfurization and desalination water washing tower is connected with the smoke inlet of the second desulfurization and desalination water washing tower, and the smoke outlet of the second desulfurization and desalination water washing tower is connected with a smoke purification system. The water outlets of the first desulfurization and desalination water washing tower and the second desulfurization and desalination water washing tower are connected with the water inlet of the neutralization desulfurization treatment device, the sludge outlet of the neutralization desulfurization treatment device is connected with the inlet of the cake separation device, the liquid in the neutralization desulfurization treatment device is circulated and cooled by the cooling tower, the liquid outlet of the neutralization desulfurization treatment device is connected with the liquid inlet of the membrane treatment device, the concentrated liquid outlet of the membrane treatment device is connected with the liquid inlet of the sodium chloride crystallization device, the material outlet of the sodium chloride crystallization device is sequentially connected with the sodium salt centrifugal device, the sodium salt drying device and the sodium salt packaging device, the liquid outlet of the sodium chloride crystallization device is connected with the liquid inlet of the potassium chloride crystallization device, the material outlet of the potassium chloride crystallization device is sequentially connected with the potassium salt centrifugal device, the potassium salt drying device and the potassium salt packaging device, the liquid outlet of the potassium chloride crystallization device is connected with the liquid inlet of the mother liquor drying device, and the material outlet of the mother liquor drying device is connected with the miscellaneous salt packaging device.

2. The system according to claim 1, wherein the system is characterized by: The steam outlet of the waste heat utilization boiler is connected with the steam inlet of the sodium chloride crystallization device, the clean water outlet of the membrane treatment device is connected with the first spraying device in the first desulfurization and desalination water washing tower and the second spraying device in the second desulfurization and desalination water washing tower, and a third spraying device is arranged in the second desulfurization and desalination water washing tower, and the water source of the third spraying device is tap water.

3. The system according to claim 1 or 2, characterized in that: The inner cavity of the secondary combustion chamber is in a U-shaped structure, the left upper end of the secondary combustion chamber is provided with an air inlet elbow joint, the right upper end of the secondary combustion chamber is provided with an air outlet elbow joint, the right end of the air outlet elbow joint is connected with the smoke gas inlet on the left side of the waste heat utilization boiler, the waste heat utilization boiler is internally provided with a baffle heat exchange channel, and the right side of the waste heat utilization boiler is provided with a smoke gas outlet. The left upper part of the secondary combustion chamber is provided with a burner mounting port, the burner mounting port is provided with a natural gas burner, the left lower part of the secondary combustion chamber is provided with a first SNCR spray gun for horizontally spraying urea solution to the right, the spraying direction of the first SNCR spray gun is along the horizontal center line of the bottom of the U-shaped cavity, and the right lower part of the secondary combustion chamber is provided with a second SNCR spray gun for vertically spraying urea solution upward, and the spraying direction of the second SNCR spray gun is along the vertical center line of the right side of the U-shaped cavity. The bottom of the secondary combustion chamber is provided with a first support, the inner cavity wall of the secondary combustion chamber is provided with a refractory castable layer, the outer part of the secondary combustion chamber is wrapped with a rock wool insulation layer, and the bottom of the secondary combustion chamber is provided with a dust falling pipe at the middle position of the U-shaped structure, and the lower end of the dust falling pipe is provided with a first valve.

4. The system according to claim 3, wherein the system is characterized by: The waste heat utilization boiler comprises a second support, a furnace chamber surrounded by an outer membrane water cooling wall is arranged on the second support, an internal membrane water cooling wall is arranged in the middle of the furnace chamber, the upper end and the lower end of the internal membrane water cooling wall are connected with the top and the bottom of the outer membrane water cooling wall respectively, the internal membrane water cooling wall divides the furnace chamber into a left heat exchange cavity and a right heat exchange cavity, the lower part of the internal membrane water cooling wall is provided with a through hole for connecting the left heat exchange cavity and the right heat exchange cavity, the flue gas inlet is arranged on the left upper part of the outer membrane water cooling wall, the flue gas outlet is arranged on the right upper part of the outer membrane water cooling wall, a boiler drum is arranged above the outer membrane water cooling wall, the boiler drum is connected with the top of the outer membrane water cooling wall through a steam rising pipe and a cold water flowing pipe, the flue gas inlet, the left heat exchange cavity, the through hole, the right heat exchange cavity and the flue gas outlet form a through baffle heat exchange channel, and a dust falling hopper is arranged at the bottom of the left heat exchange cavity and the right heat exchange cavity respectively, and the lower end of the dust falling hopper is provided with a second valve.

5. The system according to claim 4, wherein the system is characterized by: The center line of the boiler drum is horizontally arranged along the left-right direction, a liquid level meter is arranged at the left end of the boiler drum, a blowdown pipe joint is arranged at the lower part of the right end of the boiler drum, a steam outlet, a safety valve interface, a safety valve standby interface and a pressure gauge interface are arranged at the top of the boiler drum, a feed water pipe joint is arranged at the upper part of the front side of the boiler drum, a feed water distribution pipe connected with the inner port of the feed water pipe joint is arranged in the boiler drum, a feed water distribution hole plate located below the feed water distribution pipe is arranged in the boiler drum, and a steam-water separator connected with the steam outlet is arranged in the upper part of the boiler drum.

Images