CN108793557B

CN108793557B - Desulfurization wastewater bypass flue evaporation treatment process and system

Info

Publication number: CN108793557B
Application number: CN201810615236.4A
Authority: CN
Inventors: 马志义; 王勇; 马永兴; 丁洁; 钟雄友
Original assignee: Longking Coalogix Environmental Protection Technology Shanghai Co ltd
Current assignee: Longking Coalogix Environmental Protection Technology Shanghai Co ltd
Priority date: 2018-06-14
Filing date: 2018-06-14
Publication date: 2021-10-22
Anticipated expiration: 2038-06-14
Also published as: CN108793557A

Abstract

The invention discloses a desulfurization wastewater bypass flue evaporation treatment process and a system, wherein the desulfurization wastewater bypass flue evaporation treatment process comprises the following steps: primary softening treatment: after lime is put into the desulfurization wastewater, carrying out precipitation treatment to obtain a treatment solution I; and (3) softening treatment again: sequentially adding sodium hydroxide and sodium carbonate along the flowing direction of the treatment liquid I, and performing TMF membrane treatment to obtain a treatment liquid II; DTRO membrane treatment: treating the treatment liquid II through a DTRO membrane to obtain a treatment liquid III and a discharge liquid; evaporating the bypass flue: and the treatment liquid III enters the evaporation tower at the top end of the evaporation tower and is atomized, and the high-temperature flue gas entering the evaporation tower from the first bypass flue of the boiler flue gas enters the top of the evaporation tower and is subjected to evaporation crystallization treatment. The method improves the treatment efficiency of the desulfurization wastewater, realizes the advanced treatment of the desulfurization wastewater, and effectively solves the problem of recycling the desulfurization wastewater in the planning design and environment-friendly upgrading and reconstruction work of coal-fired power plants.

Description

Desulfurization wastewater bypass flue evaporation treatment process and system

Technical Field

The invention relates to the technical field of desulfurization wastewater treatment, in particular to a desulfurization wastewater bypass flue evaporation treatment process and a desulfurization wastewater bypass flue evaporation treatment system.

Background

The domestic power plants mostly adopt a gypsum-limestone wet desulphurization treatment process to carry out desulphurization treatment on the flue gas, but the process has the defects of generating waste water, wherein the pH value of the waste water is 5-6, and the waste water contains a large amount of salts, wherein magnesium ions and calcium ions are the most important; meanwhile, the gypsum powder also contains gypsum particles, SO2, Al and iron hydroxide; fluoride and heavy metals such As As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, etc. Because the process flue gas contains a small amount of fluoride ions, chloride ions and various impurities brought by raw coal, the process flue gas enters a desulfurization absorption tower, is washed and enters slurry, and the combined action of the fluoride ions and aluminum in the slurry has shielding influence on the dissolution of limestone of a desulfurization absorbent, the solubility of the limestone is weakened, and the desulfurization efficiency is reduced; meanwhile, too high concentration of chloride ions has a corrosive effect on the system and the structure of the absorption tower. Thus, the gypsum-limestone wet desulfurization treatment process generally requires discharging a part of filtrate water as desulfurization waste water for the purpose of controlling the concentrations of chloride ions and fluoride ions and maintaining the material balance of the absorption tower.

The desulfurization wastewater has high salt content, complex composition, corrosivity and strong pollution, can be discharged only after being treated independently, or causes great pollution to the environment. In addition, in order to improve the comprehensive utilization rate of water resources, power plants generally use various kinds of discharged water such as reverse osmosis concentrated water, circulating system waste water and the like as water sources of a wet flue gas desulfurization system process. The desulfurization wastewater becomes wastewater with the worst water quality at the tail end of a coal-fired power plant system. Therefore, the advanced treatment of the desulfurization wastewater and the realization of the recycling of the desulfurization wastewater become new challenges for the planning design and environmental upgrading and reconstruction of coal-fired power plants.

Disclosure of Invention

The invention aims to provide a desulfurization wastewater bypass flue evaporation treatment process and a system, which improve the treatment efficiency of desulfurization wastewater and realize the advanced treatment of desulfurization wastewater; the difficult problem of recycling of the desulfurization wastewater in the planning design and environment-friendly upgrading and reconstruction work of the coal-fired power plant is effectively solved.

The technical scheme provided by the invention is as follows:

an evaporation treatment process for a desulfurization wastewater bypass flue comprises the following steps:

primary softening treatment: after lime is put into the desulfurization wastewater, carrying out precipitation treatment to obtain a treatment solution I;

and (3) softening treatment again: sequentially adding sodium hydroxide and sodium carbonate along the flowing direction of the treatment liquid I, and performing TMF membrane treatment to obtain a treatment liquid II;

DTRO membrane treatment: treating the treatment liquid II through a DTRO membrane to obtain a treatment liquid III and a discharge liquid;

evaporating the bypass flue: and the treatment liquid III enters the evaporation tower at the top end of the evaporation tower and is atomized, and the high-temperature flue gas entering the evaporation tower from the first bypass flue of the boiler flue gas enters the top of the evaporation tower and is subjected to evaporative crystallization treatment to obtain mixed flue gas and sediment impurities.

According to the technical scheme, after most of magnesium ions and calcium ions are removed through two-stage softening, desulfurization wastewater after front-end pretreatment (namely primary softening treatment and secondary softening treatment) is further treated through DTRO (disc tube reverse osmosis) to obtain good effluent quality, so that discharge liquid can be directly discharged, and treatment liquid III from a concentrated water end of the DTRO is subjected to evaporative crystallization treatment through a bypass flue evaporation treatment to obtain mixed flue gas and sedimentation impurities, wherein the sedimentation impurities comprise metal ions in the treatment liquid III, magnesium ions, calcium ions and other salts; therefore, substances harmful to the environment in the mixed flue gas are further reduced, the treatment efficiency of the desulfurization wastewater is greatly improved, and the advanced treatment of the desulfurization wastewater is realized; the difficult problem of recycling of the desulfurization wastewater in the planning design and environment-friendly upgrading and reconstruction work of the coal-fired power plant is effectively solved. The method actively responds to the policy of China on environmental protection, provides effective guarantee for deduction and exemption of environmental protection taxes of enterprises, and has good market prospect and competitiveness. More preferably, the system has small floor area and high space utilization rate, and accords with the current situation of China's margin, thereby reducing the cost of enterprises.

Further preferably, the bypass flue evaporation treatment further comprises: high-temperature flue gas entering the evaporation tower from a second bypass flue of the boiler flue gas enters the bottom end of the evaporation tower and is subjected to evaporation treatment on the deposition sundries deposited at the bottom of the evaporation tower; and/or, the bypass flue evaporation treatment further comprises: and (3) dust removal treatment: treating the mixed flue gas by a dust removal device to obtain dust and water vapor; and (3) recycling water vapor: the water vapor is mixed with the flue gas flowing out of the main flue of the boiler flue gas and then enters a desulfurization system to supplement water.

In the technical scheme, high-temperature flue gas enters the inner space of the evaporation tower through the top end and the bottom end of the evaporation tower respectively, and one path of high-temperature flue gas flows from top to bottom, so that atomized desulfurization wastewater is heated and evaporated, low-boiling-point substances (mainly water) in the desulfurization wastewater are evaporated, and high-boiling-point substances are lowered to the bottom end under the self gravity of the high-boiling-point substances; the other path of high-temperature flue gas circulates from bottom to top, and the sedimentation impurities at the bottom are heated, so that substances (mainly water) with low boiling point of the sedimentation impurities are further heated and evaporated to form a fluid state, the water content of the sedimentation impurities is further reduced, and the sedimentation impurities (dust and salt crystals) with the reduced water content are discharged from the bottom of the evaporation tower; and the mixed flue gas mixed with the high-temperature flue gas and the steam is discharged from the evaporation tower for reprocessing and then is discharged or recycled. Because the high temperature flue gas of the same way circulates from top to bottom, and the high temperature flue gas of the other way circulates from bottom to top, thereby take place the turbulent flow in the inner space of evaporating tower, make high temperature flue gas and desulfurization waste water intensive mixing contact, improved the evaporation efficiency of evaporating tower greatly, make under the condition of handling the same desulfurization waste water volume, this evaporating tower can be littleer, radial dimension can be littleer than the height of current evaporating tower, greatly reduced desulfurization waste water treatment system's space occupancy.

Further preferably, the primary softening treatment comprises: and (3) pH adjustment treatment: lime is put into the desulfurization wastewater in the regulating reservoir and stirred to obtain flocculation liquid; and (3) precipitation treatment: the flocculated liquid is separated in a clarification tank to form a treatment liquid I and sludge I.

According to the technical scheme, because the desulfurization wastewater is high in salt content, complex in composition and the pH value of the effluent of the general desulfurization wastewater is 5-6, in order to reduce the treatment load of the subsequent process and improve the treatment efficiency of the desulfurization wastewater, lime is added into the front-end desulfurization wastewater, so that metal ions or particles are subjected to physicochemical reaction and are flocculated and bonded to form a flocculating constituent with larger particles, and in order to improve the effect that the lime and the desulfurization wastewater can be fully mixed, the lime is added and the stirring is carried out at the same time; thereby leading the desulfurization waste water to generate more flocculating constituents, and then carrying out precipitation separation on the desulfurization waste water containing the flocculating constituents.

Further preferably, the re-softening treatment comprises: and (3) magnesium ion removal treatment: putting sodium hydroxide at the front end of the flow direction of the treatment fluid I; calcium ion removal treatment: adding sodium carbonate at the middle end of the treating fluid I in the flowing direction; TMF film treatment: and performing TMF membrane treatment on the tail end of the treatment liquid I in the flowing direction to obtain the treatment liquid II and a turbid liquid, and refluxing the turbid liquid to the tail end of the treatment liquid I in the flowing direction to perform TMF membrane treatment.

In the technical scheme, in order to further reduce the load of subsequent DTRO membrane treatment, metal ions, magnesium ions and calcium ions in the desulfurization wastewater are further removed, and the concentrated solution of TMF (tubular microfiltration membrane) is subjected to reflux retreatment, so that the treatment efficiency of the process is improved.

Further preferably, the method also comprises the following steps: collecting and treating the sludge I obtained by the primary softening treatment and the sludge II obtained by the secondary softening treatment to obtain sludge cakes and sludge liquid; and (3) recovery treatment: and after the sludge liquid is recovered and mixed with desulfurization wastewater, sequentially carrying out primary softening treatment, secondary softening treatment, DTRO membrane treatment and bypass flue evaporation treatment.

The invention also discloses a desulfurization wastewater bypass flue evaporation treatment system, which comprises:

a primary softening treatment system for performing a primary softening treatment; after lime is put into the desulfurization wastewater in the primary softening treatment system, carrying out precipitation treatment to obtain a treatment solution I;

a re-softening treatment system for performing a re-softening treatment; sequentially adding sodium hydroxide and sodium carbonate in the re-softening treatment system along the flowing direction of the treatment liquid I, and performing TMF membrane treatment to obtain a treatment liquid II;

a DTRO membrane treatment system for performing DTRO membrane treatment; the DTRO membrane treatment system is used for treating the treatment liquid II to obtain a treatment liquid III and a discharge liquid; and the number of the first and second groups,

a bypass flue evaporation treatment system for performing bypass flue evaporation treatment; and the treatment liquid III enters the evaporation tower from the top end of the evaporation tower of the bypass flue evaporation treatment system and is atomized, and the high-temperature flue gas entering the evaporation tower from the first bypass flue of the boiler flue gas enters the top of the evaporation tower and is subjected to evaporation crystallization treatment to obtain mixed flue gas and sedimentation impurities.

According to the technical scheme, after most of metal ions, magnesium ions and calcium ions are removed through two-stage softening, desulfurization wastewater after front-end pretreatment (namely primary softening treatment and secondary softening treatment) is further treated through DTRO (disc tube reverse osmosis) to obtain good effluent quality, so that discharge liquid can be directly discharged, and meanwhile, treatment liquid III from a concentrated water end of the DTRO is subjected to evaporative crystallization treatment through a bypass flue evaporation treatment to obtain mixed flue gas and sedimentation impurities, wherein the sedimentation impurities comprise metal ions in the treatment liquid III, magnesium ions, calcium ions and other salts; therefore, substances harmful to the environment in the mixed flue gas are further reduced, the treatment efficiency of the desulfurization wastewater is greatly improved, and the advanced treatment of the desulfurization wastewater is realized; the difficult problem of recycling of the desulfurization wastewater in the planning design and environment-friendly upgrading and reconstruction work of the coal-fired power plant is effectively solved. The method actively responds to the policy of China on environmental protection, provides effective guarantee for deduction and exemption of environmental protection taxes of enterprises, and has good market prospect and competitiveness. More preferably, the system has small floor area and high space utilization rate, and accords with the current situation of China's territory and countryside, thereby reducing the cost of enterprises.

Further preferably, a second pipeline of a second bypass flue for circulating the boiler flue gas is arranged at the bottom end of the evaporation tower, so that the treatment liquid III enters the evaporation tower from the top end of the evaporation tower, and the high-temperature flue gas entering the evaporation tower from the second bypass flue of the boiler flue gas enters the bottom end of the evaporation tower through the second pipeline and carries out evaporation treatment on the deposition impurities deposited at the bottom of the evaporation tower; and/or the bypass flue evaporation treatment system also comprises a dust removal device and a pipeline flowing to the desulfurization system; enabling the dust removal device to treat the mixed flue gas to obtain dust and water vapor; and the steam flows to a desulfurization system through the pipeline to supplement water.

In the technical scheme, high-temperature flue gas enters the inner space of the evaporation tower through the top end and the bottom end of the evaporation tower respectively, and one path of high-temperature flue gas flows from top to bottom, so that atomized desulfurization wastewater is heated and evaporated, low-boiling-point substances (mainly water) in the desulfurization wastewater are evaporated, and high-boiling-point substances are lowered to the bottom end under the self gravity of the high-boiling-point substances; the other path of high-temperature flue gas circulates from bottom to top, and the sedimentation impurities at the bottom are heated, so that the substances (mainly water) with low boiling point of the sedimentation impurities are further heated and evaporated, the water content of the sedimentation impurities is further reduced, and the sedimentation impurities (dust and salt crystals) with low water content are discharged from the bottom of the evaporation tower; and the mixed flue gas mixed with the high-temperature flue gas and the steam is discharged from the evaporation tower for reprocessing and then is discharged or recycled. Because the high temperature flue gas of the same way circulates from top to bottom, and the high temperature flue gas of the other way circulates from bottom to top, thereby take place the turbulent flow in the inner space of evaporating tower, make high temperature flue gas and desulfurization waste water intensive mixing contact, improved the evaporation efficiency of evaporating tower greatly, make under the condition of handling the same desulfurization waste water volume, this evaporating tower can be littleer, radial dimension can be littleer than the height of current evaporating tower, greatly reduced desulfurization waste water treatment system's space occupancy.

Further preferably, the primary softening treatment system comprises a first reaction tank for performing pH adjustment treatment, and a stirring device is arranged inside the first reaction tank; and a clarification tank; the first reaction tank and the clarification tank are connected in sequence.

Further preferably, the re-softening treatment system comprises: a second reaction tank for performing magnesium ion removal treatment; a third reaction tank for performing a calcium ion removal treatment; and a TMF film device for performing TMF film processing; the TMF membrane device comprises a TMF concentration tank, a TMF membrane structure and a reflux pump; the TMF membrane structure is provided with a water inlet pipe, a clear liquid outlet pipe and a turbid liquid outlet pipe; the second reaction tank, the third reaction tank, the TMF concentration tank, the water inlet pipe, the clear liquid outlet pipe and the DTRO membrane treatment system are sequentially and fluidly connected; the turbid liquid outlet pipe is fluidly coupled to the TMF concentrator tank by a reflux pump.

Further preferably, the system also comprises a sludge treatment system for sludge treatment; the sludge treatment system collects and treats the sludge I obtained by the primary softening treatment system and the sludge II obtained by the secondary softening treatment system to obtain sludge cakes and sludge liquid; and a recycling treatment pipeline for recycling treatment, wherein the recycling treatment pipeline is used for returning the sludge liquid to the primary softening treatment system.

In this technical scheme, for the convenience of sludge recycle, mud generally need carry out dehydration treatment, but the produced water of dehydration treatment can contain harmful environment's material, like heavy metal, consequently, the accessible flows back sludge liquid to the front end of this technology for retreatment after sludge liquid mixes with the desulfurization waste water that the power plant newly generated, thereby realized the pollution zero release of this technology.

The desulfurization wastewater bypass flue evaporation treatment process and the system provided by the invention can bring at least one of the following beneficial effects:

1. according to the invention, after most of magnesium ions and calcium ions are removed through two-stage softening, desulfurization wastewater after front-end pretreatment (namely primary softening treatment and secondary softening treatment) is further treated through DTRO (disc tube reverse osmosis) to obtain good effluent quality, so that discharge liquid can be directly discharged, and meanwhile, treatment liquid III at a concentrated water end of the DTRO is subjected to evaporation crystallization treatment through a bypass flue evaporation treatment to obtain mixed flue gas and sedimentation impurities, wherein the sedimentation impurities comprise metal ions in the treatment liquid III, magnesium ions, calcium ions and other salts; therefore, substances harmful to the environment in the mixed flue gas are further reduced, the treatment efficiency of the desulfurization wastewater is greatly improved, and the advanced treatment of the desulfurization wastewater is realized; the difficult problem of recycling of the desulfurization wastewater in the planning design and environment-friendly upgrading and reconstruction work of the coal-fired power plant is effectively solved. The method actively responds to the policy of China on environmental protection, provides effective guarantee for deduction and exemption of environmental protection taxes of enterprises, and has good market prospect and competitiveness. Preferably, the system corresponding to the process has small occupied area and high space utilization rate, and meets the current situation of China's territory and gold, thereby reducing the cost of enterprises.

2. In the invention, high-temperature flue gas enters the internal space of the evaporation tower through the top end and the bottom end of the evaporation tower respectively, and one path of high-temperature flue gas flows from top to bottom, so that atomized desulfurization wastewater is heated and evaporated, low-boiling-point substances (mainly water) in the desulfurization wastewater are evaporated, and high-boiling-point substances sink to the bottom end under the self gravity of the high-boiling-point substances; the other path of high-temperature flue gas circulates from bottom to top, and the sedimentation impurities at the bottom are heated, so that the substances (mainly water) with low boiling point of the sedimentation impurities are further heated and evaporated, the water content of the sedimentation impurities is further reduced, and the sedimentation impurities (dust and salt crystals) with low water content are discharged from the bottom of the evaporation tower; and the mixed flue gas mixed with the high-temperature flue gas and the steam is discharged from the evaporation tower for reprocessing and then is discharged or recycled. Because the high temperature flue gas of the same way circulates from top to bottom, and the high temperature flue gas of the other way circulates from bottom to top, thereby take place the turbulent flow in the inner space of evaporating tower, make high temperature flue gas and desulfurization waste water intensive mixing contact, improved the evaporation efficiency of evaporating tower greatly, make under the condition of handling the same desulfurization waste water volume, this evaporating tower can be littleer, radial dimension can be littleer than the height of current evaporating tower, greatly reduced desulfurization waste water treatment system's space occupancy.

Drawings

The above features, technical features, advantages and implementations of a desulfurization waste water bypass flue evaporation treatment process and system will be further described in the following detailed description of preferred embodiments in a clearly understandable manner with reference to the accompanying drawings.

FIG. 1 is a flow chart of an embodiment of the desulfurization waste water bypass flue evaporation treatment process of the present invention;

FIG. 2 is a schematic structural diagram of an embodiment of the desulfurization wastewater bypass flue evaporation treatment system of the invention;

FIG. 3 is a schematic structural diagram of another embodiment of the desulfurization wastewater bypass flue evaporation treatment system of the invention;

FIG. 4 is a schematic structural diagram of an embodiment of a bypass flue evaporation treatment system of the invention.

The reference numbers illustrate:

11. a regulating reservoir, 12, a first reaction tank, 13, a clarification tank, 21, an intermediate water tank, 22, a second reaction tank, 23, a third reaction tank, 241, a TMF concentration tank, 242, a TMF membrane structure, 243, a reflux pump, 244, a water inlet pipe, 245, a clear water outlet pipe, 246, a turbid liquid outlet pipe, 31, a pH adjusting tank, 32, a DT raw water tank, 33, a DTRO membrane structure, 34, a discharge liquid tank, 35, a treatment liquid III tank, 41, an evaporation tower, 4111, a first pipeline, 4112, a second pipeline, 4113, a circulating pump, 4114, a treatment liquid III pipeline, 4115, a fan, 4116, a high-temperature flue gas inlet header pipe, 412, sedimentation debris, 413, a spray layer, 4131, a sprayer, 414, a third pipeline, 415, a fourth pipeline, 416, a first deflector, 417, a second deflector, 418, a first control valve, 419, a second control valve, 42, a dust removal device, 51, sludge, 52, a plate frame, 61, a filter press filter, 7. the system comprises a dust removing chamber, 71, a baffle plate, 72, an air outlet pipeline, 8, an ash storehouse and 9, a desulfurization system.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

For the sake of simplicity, the drawings only schematically show the parts relevant to the present invention, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one". In this context, it is to be understood that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the first embodiment, as shown in fig. 1, a desulfurization wastewater bypass flue evaporation treatment process includes the steps of:

In the embodiment, lime (namely calcium hydroxide) is added into the desulfurization wastewater for pH adjustment in the dedusting softening treatment, so that the treatment liquid I meets the pH treatment condition of the secondary softening treatment; and part of metal ions can also generate physicochemical reaction to generate flocculation, bridging and bonding to form a flocculating constituent; and is removed by a precipitation process. Sequentially adding sodium hydroxide and sodium carbonate in the flowing direction of the treatment liquid I in the softening treatment again, so that magnesium ions and calcium ions in the treatment liquid I sequentially undergo physicochemical reaction to generate flocculation, bridging and bonding to form a floccule, then filtering through TMF to remove the magnesium ions and the calcium ions in the treatment liquid I sequentially, and treating the obtained treatment liquid II through DTRO; obtaining good effluent quality, so that the effluent can be directly discharged (certainly, the effluent can also be recycled, such as the water quantity requirement of a desulfurization system is provided to the desulfurization system), and the treatment liquid III at the concentrated water end of the DTRO is subjected to evaporation crystallization treatment through a bypass flue evaporation treatment to obtain mixed flue gas and sedimentation impurities, wherein the sedimentation impurities comprise metal ions in the treatment liquid III, magnesium ions, calcium ions and other salts; therefore, substances harmful to the environment in the mixed flue gas are further reduced, the treatment efficiency of the desulfurization wastewater is greatly improved, and the advanced treatment of the desulfurization wastewater is realized; the difficult problem of recycling of the desulfurization wastewater in the planning design and environment-friendly upgrading and reconstruction work of the coal-fired power plant is effectively solved. The method actively responds to the policy of China on environmental protection, provides effective guarantee for deduction and exemption of environmental protection taxes of enterprises, and has good market prospect and competitiveness. More preferably, the system has small floor area and high space utilization rate, and accords with the current situation of China's margin, thereby reducing the cost of enterprises.

In a second embodiment, as shown in fig. 1, on the basis of any one of the above embodiments, the bypass flue evaporation treatment further includes: and the high-temperature flue gas entering the evaporation tower from the second bypass flue of the boiler flue gas enters the bottom end of the evaporation tower and carries out evaporation treatment on the deposition sundries deposited at the bottom of the evaporation tower.

In this embodiment, the high-temperature flue gas enters the internal space of the evaporation tower through the top end and the bottom end of the evaporation tower respectively, and one path of the high-temperature flue gas circulates from top to bottom, so that the atomized desulfurization wastewater is heated and evaporated, and low-boiling-point substances (mainly water) in the desulfurization wastewater are evaporated, while high-boiling-point substances sink to the bottom end under the self-gravity thereof; the other path of high-temperature flue gas circulates from bottom to top, and the sedimentation impurities at the bottom are heated, so that the substances (mainly water) with low boiling point of the sedimentation impurities are further heated and evaporated, the water content of the sedimentation impurities is further reduced, and the sedimentation impurities (dust and salt crystals) with low water content are discharged from the bottom of the evaporation tower; and the mixed flue gas mixed with the high-temperature flue gas and the steam is discharged from the evaporation tower for reprocessing and then is discharged or recycled. Because the high temperature flue gas of the same way circulates from top to bottom, and the high temperature flue gas of the other way circulates from bottom to top, thereby take place the turbulent flow in the inner space of evaporating tower, make high temperature flue gas and desulfurization waste water intensive mixing contact, improved the evaporation efficiency of evaporating tower greatly, make under the condition of handling the same desulfurization waste water volume, this evaporating tower can be littleer, radial dimension can be littleer than the height of current evaporating tower, greatly reduced desulfurization waste water treatment system's space occupancy.

In a third embodiment, as shown in fig. 1, on the basis of any one of the above embodiments, the bypass flue evaporation treatment further includes: and (3) dust removal treatment: treating the mixed flue gas by a dust removal device to obtain dust and water vapor; and (3) recycling water vapor: the water vapor is mixed with the flue gas flowing out of the main flue of the boiler flue gas and then enters a desulfurization system to supplement water.

In practical application, if between, directly let in desulfurization system with mixed flue gas, can produce unfavorable to desulfurization system, because desulfurization waste water contains a large amount of salt, consequently, mixed flue gas also can contain a small amount of salt, and these salts can mix with the dust particulate matter in original boiler, bring adverse effect to boiler dust particulate matter's recovery and recycle. This embodiment is through dust collector to the particulate matter in the mixed flue gas that comes out from the evaporating tower interception subside to reduce the concentration of the metal particle thing in the particulate matter in the mixed flue gas, avoid bringing adverse effect for the recovery of mixing the flue gas, reduce the maintenance cost and the use cost of system.

In a fourth embodiment, as shown in fig. 1, on the basis of any one of the above embodiments, the primary softening process includes: and (3) pH adjustment treatment: lime is put into the desulfurization wastewater in the regulating reservoir and stirred to obtain flocculation liquid; and (3) precipitation treatment: the flocculated liquid is separated in a clarification tank to form a treatment liquid I and sludge I.

In the embodiment, because the desulfurization wastewater has high salt content and complex composition, and the pH of the effluent of the general desulfurization wastewater is between 5 and 6, in order to reduce the treatment load of the subsequent process and improve the treatment efficiency of the desulfurization wastewater, lime is firstly added into the front-end desulfurization wastewater, so that metal ions or particles are subjected to physicochemical reaction and are flocculated and bonded to form floccules with larger particles, and in order to improve the effect that the lime and the desulfurization wastewater can be fully mixed, the lime is added and the mixture is stirred; thereby leading the desulfurization waste water to generate more flocculating constituents, and then carrying out precipitation separation on the desulfurization waste water containing the flocculating constituents.

In a fifth embodiment, as shown in fig. 1, the re-softening process includes, in addition to any of the above embodiments: and (3) magnesium ion removal treatment: putting sodium hydroxide at the front end of the flow direction of the treatment fluid I; calcium ion removal treatment: adding sodium carbonate at the middle end of the treating fluid I in the flowing direction; TMF film treatment: and performing TMF membrane treatment on the tail end of the treatment liquid I in the flowing direction to obtain the treatment liquid II and a turbid liquid, and refluxing the turbid liquid to the tail end of the treatment liquid I in the flowing direction to perform TMF membrane treatment.

In this embodiment, in order to further reduce the load of subsequent DTRO membrane treatment, metal ions, magnesium ions, and calcium ions in the desulfurization wastewater are further removed, and the concentrated solution of TMF (tubular microfiltration membrane) is subjected to reflux retreatment, thereby improving the treatment efficiency of the process.

In a sixth embodiment, as shown in fig. 1, the method further includes a sludge treatment step in addition to any one of the above embodiments: collecting and treating the sludge I obtained by the primary softening treatment and the sludge II obtained by the secondary softening treatment to obtain sludge cakes and sludge liquid; and (3) recovery treatment: and after the sludge liquid is recovered and mixed with desulfurization wastewater, sequentially carrying out primary softening treatment, secondary softening treatment, DTRO membrane treatment and bypass flue evaporation treatment.

In this embodiment, in order to facilitate sludge recycling, sludge generally needs to be dewatered, but the water produced by dewatering contains substances harmful to the environment, such as heavy metals, so the sludge liquid can be returned to the front end of the process, and the sludge liquid and the desulfurization wastewater newly generated by the power plant are mixed and then treated, thereby realizing zero pollution discharge of the process.

In embodiment seven, as shown in fig. 1, the DTRO membrane treatment further comprises, on the basis of any of the above embodiments:

backwashing: the effluent backflushes the DTRO membrane.

In the embodiment, the discharge liquid of the DTRO reaches the discharge standard, but in practical application, the DTRO needs to be regularly washed so as to be repeatedly utilized, so that the use cost of the process and the system is reduced while the treatment efficiency of the DTRO is ensured, and the environmental protection cost investment of enterprises is reduced; and the discharged liquid is recycled, so that the process forms a high standard of zero emission.

In example eight, as shown in fig. 2 and 3, a desulfurization waste water bypass flue evaporation treatment system includes: a primary softening treatment system for performing a primary softening treatment; after lime is put into the desulfurization wastewater in the primary softening treatment system, carrying out precipitation treatment to obtain a treatment solution I; a re-softening treatment system for performing a re-softening treatment; sequentially adding sodium hydroxide and sodium carbonate in the re-softening treatment system along the flow direction of the treatment liquid I, and performing TMF membrane treatment to obtain a treatment liquid II; a DTRO membrane treatment system for performing DTRO membrane treatment; treating the treatment liquid II by the DTRO membrane treatment system to obtain a treatment liquid III and a discharge liquid; the bypass flue evaporation treatment system is used for performing bypass flue evaporation treatment; the treatment liquid III enters the evaporation tower 41 of the bypass flue evaporation treatment system at the top end of the evaporation tower 41 and is atomized, and the high-temperature flue gas entering the evaporation tower 41 at the first bypass flue of the boiler flue gas enters the top of the evaporation tower 41 and is subjected to evaporation crystallization treatment to obtain mixed flue gas and sedimentation impurities.

In the ninth embodiment, as shown in fig. 2 and 3, on the basis of the eighth embodiment, a second pipeline 4112 for flowing through a second bypass flue of the boiler flue gas is arranged at the bottom end of the evaporation tower 41, so that the treatment liquid III enters the evaporation tower 41 at the top end of the evaporation tower 41, and the high-temperature flue gas entering the evaporation tower 41 at the second bypass flue of the boiler flue gas enters the bottom end of the evaporation tower 41 through the second pipeline 4112 and evaporates the settled impurities settled at the bottom of the evaporation tower 41; the first bypass flue and the second bypass flue are arranged in parallel. Preferably, the first bypass flue and the second bypass flue are connected in parallel and then communicated with the high temperature flue gas inlet header 4116, and the high temperature flue gas inlet header 4116 is connected in parallel with the flue gas main path (i.e. the pipeline for circulating the high temperature flue gas entering the preheater 61) and then communicated with the boiler. Preferably, in order to facilitate the communication of the first bypass flue with the evaporation tower 41, a first duct 4111 is provided at the top of the evaporation tower 41. Preferably, the bypass flue evaporation treatment system further comprises a dust removal device and a pipeline flowing to the desulfurization system 9; enabling the dust removal device to treat the mixed flue gas to obtain dust and water vapor (probably at 120-140 ℃); the steam flows through the pipeline to the desulfurization system 9 to supplement the water. It is worth noting that the effluent from the DTRO membrane treatment system may also be used to supplement the desulfurization system 9 with water.

In the tenth embodiment, as shown in fig. 2 and 3, on the basis of the eighth or ninth embodiment, the evaporation tower 41 includes a tower body, and the tower body is provided with: a first flue gas inlet section, a spraying section for spraying a spraying layer 413 of the treatment liquid III, a mixed flue gas outlet section, and a skirt section for receiving the sediment 412; the first flue gas inlet section is provided with a first pipeline 4111 for communicating high-temperature flue gas of the first bypass flue; the skirt section is provided with a second pipeline 4112 for communicating the high-temperature flue gas of the second bypass flue, and the second pipeline 4112 is connected with the first pipeline 4111 in parallel; the spraying section is provided with a sprayer 4131 arranged towards one side of the flue gas outlet section, and a spraying layer 413 is formed by the plurality of sprayers 4131; the mixed flue gas outlet section is provided with a third pipeline 414 for flowing out mixed flue gas; the lower end of the skirt section is provided with a fourth conduit 415 for outflow of settled impurities 412.

In practical application, the treatment liquid III is atomized and sprayed by the sprayer 4131, and then heated and evaporated by the high-temperature flue gas discharged from the first pipeline 4111, and meanwhile, the high-temperature flue gas discharged from the second pipeline 4112 flows from the lower part to the upper part, so as to further heat and dehydrate the deposit impurities 412 flowing from the upper part to the lower part, and the mixed flue gas (the mixed gas of the high-temperature flue gas and the flue gas evaporated in the treatment liquid III) further, thereby reducing the water content of the deposit impurities 412 (the particles and the salt crystals) flowing out from the fourth pipeline 415, and the mixed flue gas at the outlet section of the mixed flue gas flows out through the third pipeline 414, and after the mixed flue gas flowing out from the third pipeline 414 is treated, the mixed flue gas can be recovered to form the high-temperature flue gas again, and then the treatment liquid III is heated and evaporated again, thereby realizing the recycling of the high-temperature flue gas and saving the cost.

In the eleventh embodiment, as shown in fig. 2 and 3, on the basis of the tenth embodiment, two spraying layers 413 are sequentially arranged on the spraying section from top to bottom; each spray layer 413 is formed by mounting a plurality of spray throwers 4131 on a spray rack, and the extension direction of the spray rack is the same as the radial direction of the tower body. The treating liquid III flows from the treating liquid III pipeline 4114 to each sprayer 4131 through the circulating pump 4113, and forms small droplets after atomization by the sprayers 4131, and the high-temperature flue gas flowing into the inner space of the tower body from the first pipeline 4111 above exchanges heat with the small droplets formed by the treating liquid III to evaporate low-boiling-point substances (such as water) in the treating liquid III, and then the mixed flue gas is led out of the inner space of the tower body through the third pipeline 414, while the heavy particulate matters and salt crystals sink to the skirt section under the action of their gravity, and the settling impurities 412 located in the skirt section further exchange heat with the high-temperature flue gas flowing from bottom to top through the second pipeline 4112 to remove water. Preferably, the sprinklers 4131 located in the different spray levels 413 are offset. Preferably, in order to facilitate the flow direction of the high-temperature flue gas, a gap is arranged between adjacent showers 4131, so that the high-temperature flue gas flowing out from the upper part can enter the mixed flue gas outlet section conveniently. Preferably, the spray 4131 is preferably a two-fluid atomization spray gun. Preferably, the second duct 4112 is disposed at any height position between 1/3-2/3 of the skirt section in the height direction thereof.

In a twelfth embodiment, as shown in fig. 2 to 4, on the basis of the tenth or eleventh embodiment, a first baffle 416 is disposed below the spray layer 413, the first baffle 416 has a first side wall and a second side wall which are disposed opposite to each other, and the first side wall of the first baffle 416 is disposed on an inner side wall of the tower body; the second side wall disposed opposite the first side wall is inclined upward. Preferably, the included angle between the first guide plate 416 and the inner side wall of the tower body ranges from 30 degrees to 75 degrees. Preferably, at least one first deflector 416 is sequentially arranged below each spraying layer 413 along the up-down direction. Preferably, the first baffle 416 is provided with a first flow guide through hole. A plurality of first flow guide through holes are arranged on the first flow guide plate 416 at intervals. Preferably, the first baffle 416 is detachably connected to the inner side wall of the tower body. Preferably, the first guide plate 416 is formed by splicing a plurality of first sub guide plates, and each first sub guide plate is detachably connected with the inner side wall of the tower body, so that when a certain first sub guide plate is damaged due to corrosion, only the damaged first sub guide plate needs to be replaced, and the cost is saved. Preferably, the first flow guide plate 416 encloses to form a hollow circular truncated cone-shaped flow guide structure, the inner diameter of the large-diameter end of the hollow circular truncated cone-shaped flow guide structure is almost the same as the inner diameter of the tower body, and the inner diameter of the small-diameter end of the hollow circular truncated cone-shaped flow guide structure is 70-95% of the inner diameter of the tower body.

In a thirteenth embodiment, as shown in fig. 2 to 4, on the basis of the tenth, eleventh or twelfth embodiment, a second guide plate 417 is disposed between the mixed flue gas outlet section and the skirt section, the second guide plate 417 has a third side wall and a fourth side wall disposed opposite to each other, and the third side wall of the second guide plate 417 is disposed on the inner side wall of the tower body; the fourth side wall disposed opposite to the third side wall is inclined downward. The high temperature flue gas that is gone out by second pipeline 4112 forms the backward flow phenomenon through blockking of the lower surface of second guide plate 417 to the dwell time of extension high temperature flue gas in the skirt section, thereby the drying effect of high temperature flue gas to subsiding debris 412 is strengthened. Preferably, the third sidewall of the second baffle 417 is disposed below the third duct 414 at a preset distance value. Preferably, the second guide plate 417 is provided with a second guide through hole. A plurality of second flow guide through holes are arranged at intervals on the second flow guide plate 417. Preferably, the second deflector 417 is detachably connected to the inner side wall of the tower. Preferably, the second guide plate 417 is formed by splicing a plurality of second sub-guide plates, and each second sub-guide plate is detachably connected with the inner side wall of the tower body, so that when a certain second sub-guide plate is damaged due to corrosion, only the damaged second sub-guide plate needs to be replaced, and the cost is saved. Preferably, the second guide plate 417 is surrounded to form a hollow circular truncated cone-shaped guide structure, the inner diameter of the large diameter end of the hollow circular truncated cone-shaped guide structure is almost the same as the inner diameter of the tower body, and the inner diameter of the small diameter end of the hollow circular truncated cone-shaped guide structure is 30-70% of the inner diameter of the tower body. Preferably, the included angle between the second guide plate 417 and the inner side wall of the tower body 1 ranges from 30 degrees to 75 degrees.

In the fourteenth embodiment, as shown in fig. 2 and 3, on the basis of the tenth, eleventh, twelfth or thirteenth embodiment, the intake end of the first duct 4111 is provided with a first control valve 418. Preferably, the air inlet end of the second duct 4112 is provided with a second control valve 419. The first pipeline 4111 and the second pipeline 4112 are connected in parallel and then connected in series with the high-temperature flue gas inlet header 4116. The flow distribution of the high-temperature flue gas in the first pipeline 4111 and the second pipeline 4112 is realized by controlling the opening degree of the first control valve 418 and the second control valve 419, and if the water content of the sediment impurities 412 is too high, the opening degree of the second control valve 419 is increased; when the treatment amount of the treatment liquid III is large, the opening degree of the first control valve 418 is increased; the working efficiency of the evaporation tower 41 is ensured. Preferably, the first control valve 418 and the second control valve 419 may be electric control valves, solenoid valves, or the like. Preferably, the high temperature flue gas from the boiler can enter the high temperature flue gas inlet header 4116 through the fan 4115, and then enter the first duct 4111 and the second duct 4112, respectively.

In the fifteenth embodiment, as shown in fig. 2 and 3, on the basis of the eighth, ninth, tenth, eleventh, twelfth, thirteenth or fourteenth embodiment, the mixed flue gas of the evaporation tower 41 sequentially flows into a dust removing device for dust removal treatment, the dust removing device is a dust removing chamber 7, the dust removing chamber 7 includes an airflow end communicated with the third duct 414, and a storage end disposed below the airflow end and used for storing the settled particulate matter; the gas flow end is provided with a gas outlet pipeline 72 communicated with the third pipeline 414, and a plurality of (one or more) baffle plates 71 are arranged on the gas flow passage of the mixed flue gas from the third pipeline 414 to the gas outlet pipeline 72. In practical application, when the mixed flue gas coming out of the third pipe 41412 flows through the airflow end of the dust removal chamber 7, the mixed flue gas is blocked by the baffle plates 71 arranged in the dust removal chamber 7, and then the speed is reduced and the mixed flue gas is collided and settled, so that heavy particles (metal particles, particularly heavy metal particles, salt crystals, particles with large volume and the like) in the mixed flue gas are removed. Preferably, the plate surface of the baffle plate 71 and the cross section of the airflow passage of the mixed flue gas form an angle, and the included angle ranges from 0 ° to 60 °, and further preferably ranges from 0 °. When the angle is acute, the end of the baffle 71 is preferably disposed obliquely toward the third tube 41412. Preferably, a plurality of (at least two) baffle plates 71 arranged along the extending direction of the airflow channel are arranged in a manner of dog-tooth staggering, that is, the baffle plate 71 arranged in front along the airflow direction is arranged below the airflow end, and the upper side wall of the baffle plate 71 is arranged above the airflow channel in a clearance manner; namely, the baffle plate 71 which is arranged at the rear in the airflow direction is arranged above the airflow end, and the lower side wall of the baffle plate 71 and the lower part of the airflow channel are arranged in a clearance; and vice versa.

Further preferably, the baffle plates 71 are arranged in a row above the gas flow end along the extending direction of the gas flow passage, the baffle plates 71 are arranged in a row below the gas flow end along the extending direction of the gas flow passage, and the baffle plates 71 in the two rows are arranged in a manner of crossing the canines. To facilitate the settling of the particles to the deposit end, a mounting bracket is provided between the airflow end and the deposit end for mounting the baffle 71, but the mounting bracket is provided with a via for the settling particles to flow to the deposit end. Preferably, the fourth pipe 415 is connected in parallel with the clean room 7 and then communicates with an ash silo 8. The dust bin 8 is used for collecting sediments (sediment sundries 4122 and sediment particles) and avoiding the occurrence of flying dust. In practical application, the ash silo 8 can realize the recovery of the sediment by utilizing the gravity principle. Certainly, the recovery of the sediment can also be realized by a fan, that is, the fan, the fourth pipeline 415 and the dust removal chamber 7 are connected in parallel and then communicated with the ash storage 8; the sediment is collected into an ash silo 8 by a fan. Preferably, the desulfurized wastewater is directed by circulation pump 4113 to treatment fluid III conduit 4114, treatment fluid III conduit 4114 being in communication with spray zone 413. Preferably, the flue gas from the preheater 61 for the flue gas of the main path of the flow-through boiler is mixed with the flue gas from the dust removal chamber 7 and then enters the desulfurization system 9 for recycling.

In the sixteenth embodiment, as shown in fig. 2 and 3, in addition to the eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth or fifteenth embodiment, the primary softening treatment system includes a first reaction tank 12 for performing pH adjustment treatment, and a stirring device is provided inside the first reaction tank 12; and a clarifier 13; the first reaction tank 12 and the clarification tank 13 are connected in sequence, so that the pH value of the treatment liquid I entering the re-softening treatment system is 9-11. In practical applications, when the desulfurization waste water is generated as intermittent water production, the front end of the first reaction tank 12 is preferably provided with a conditioning tank 11 for storing the desulfurization waste water. Of course, if the desulfurization waste water is produced continuously, the front end of the first reaction tank 12 does not need to be provided with the equalizing basin 11. The DTRO of the invention is suitable for both intermittent type and continuous type, has good elastic working capacity, and can meet the requirements of different users. Preferably, the re-softening treatment system comprises: a second reaction tank 22 for performing magnesium ion removal treatment; a third reaction tank 23 for performing calcium ion removal treatment; and a TMF film device for performing TMF film processing; the TMF membrane device comprises a TMF concentration tank 241, a TMF membrane structure 242 and a reflux pump 243; the TMF membrane structure 242 is provided with a water inlet pipe 244, a clear liquid outlet pipe 245 and a turbid liquid outlet pipe 246; the second reaction tank 22, the third reaction tank 23, the TMF concentration tank 241, the clear liquid outlet pipe of the water inlet pipe 244 and the DTRO membrane treatment system are sequentially and fluidly connected; a turbidity outlet pipe 246 is fluidly coupled to the TMF thickening tank 241 by a reflux pump 243. When the water yield of the primary softening treatment system is less and the unit time treatment capacity of the secondary softening treatment system is not satisfied, an intermediate water tank 21 for collecting treatment liquid I is preferably arranged between the TMF concentration tank 241 and the clarification tank 13, so that the secondary softening treatment system can operate after the primary softening treatment system operates for a certain time, the operation scheme of the system is optimized, and the cost is saved.

Similarly, when the treatment liquid ii obtained by the re-softening treatment system does not satisfy the treatment capacity per unit time of the DTRO membrane treatment system, the DT raw water tank 32 for collecting the treatment liquid ii is preferably provided between the clear liquid outlet pipe 245 and the DTRO membrane treatment system. Preferably, because the DTRO membrane treatment system has poor capability of treating alkaline wastewater, in order to ensure the effluent quality of the DTRO membrane treatment system, the front end of the DTRO membrane treatment system is preferably provided with a pH adjusting box 31 for adjusting the pH, so that the pH of the treatment liquid ii entering the DT raw water tank 32 is about 7. In order to save the washing cost of the DTRO membrane structure 33, it is preferable to recycle the effluent as washing water of the DTRO membrane structure 33, and therefore, it is preferable that a discharge liquid tank 34 for collecting the effluent is connected to a clean water outlet of the DTRO membrane structure 33. Preferably, a treatment liquid III tank 35 for collecting the treatment liquid III is provided at the turbid water outlet end of the DTRO membrane structure 33. In practical application, the operation of the whole system can be adjusted by adjusting the water inflow at the front end of the DTRO treatment system (i.e., the unit time treatment capacity of the DTRO membrane structure 33), the water outflow of the treatment liquid III at the rear end of the DTRO membrane structure 33 (or the water outflow of the treatment liquid III tank 35, the flow of the high-temperature flue gas of the first bypass flue, and the flow of the high-temperature flue gas of the second bypass flue).

In seventeenth embodiment, as shown in fig. 2 and 3, the eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth or sixteenth embodiment further comprises a sludge treatment system for performing sludge treatment; the sludge treatment system collects and treats sludge I obtained by the primary softening treatment system and sludge II obtained by the secondary softening treatment system (namely sludge generated by the TMF concentration tank 241) to obtain sludge cakes and sludge liquid; and a recovery processing line for recovery processing for returning the sludge liquid to the primary softening processing system (i.e., the equalizing tank 11 or the first reaction tank 12). Preferably, the sludge treatment system comprises a sludge storage tank 51 and a plate and frame filter press 52, wherein the sludge storage tank 51 is respectively communicated with the clarification tank 13 and the bottom of the TMF thickening tank 241, and the plate and frame filter press 52 is used for compressing sludge in the sludge storage tank 51.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The desulfurization wastewater bypass flue evaporation treatment process is characterized by comprising the following steps:

evaporating the bypass flue: the treatment liquid III enters the evaporation tower at the top end of the evaporation tower and is atomized, high-temperature flue gas entering the evaporation tower from a first bypass flue of boiler flue gas enters the top of the evaporation tower and is subjected to evaporative crystallization treatment, and mixed flue gas and sediment impurities are obtained; the bypass flue evaporation treatment further comprises: high-temperature flue gas entering the evaporation tower from a second bypass flue of the boiler flue gas enters the bottom end of the evaporation tower and is subjected to evaporation treatment on the deposition sundries deposited at the bottom of the evaporation tower; wherein, the evaporation tower includes the tower body, and the tower body is equipped with from the top down along its direction of height in proper order: the first flue gas inlet section, the spraying section, the mixed flue gas outlet section and the skirt section; the first flue gas inlet section is provided with a first pipeline for communicating high-temperature flue gas of the first bypass flue; the skirt section is provided with a second pipeline for passing through the high-temperature flue gas of the second bypass flue, and the second pipeline is connected with the first pipeline in parallel; the spraying section is provided with sprayers arranged towards one side of the flue gas outlet section, and the sprayers form a spraying layer; the mixed flue gas outlet section is provided with a third pipeline for flowing out mixed flue gas; the lower end of the skirt section is provided with a fourth pipeline for discharging the settled impurities; a first guide plate is arranged below the spraying layer, the first guide plate is provided with a first side wall and a second side wall which are oppositely arranged, the first side wall is arranged on the inner side wall of the tower body, and the second side wall is inclined upwards; be equipped with the second guide plate between mixed flue gas export section and the skirt section, the second guide plate has relative third lateral wall and the fourth lateral wall that sets up, the third lateral wall sets up in the inside wall of tower body, and is located the below of third pipeline, the fourth lateral wall is slope down.

2. The desulfurization wastewater bypass flue evaporation treatment process according to claim 1, wherein the bypass flue evaporation treatment further comprises:

and (3) dust removal treatment: treating the mixed flue gas by a dust removal device to obtain dust and water vapor;

and (3) recycling water vapor: the water vapor is mixed with the flue gas flowing out of the main flue of the boiler flue gas and then enters a desulfurization system to supplement water.

3. The desulfurization wastewater bypass flue evaporation treatment process of claim 1, wherein the primary softening treatment comprises:

and (3) pH adjustment treatment: lime is put into the desulfurization wastewater in the regulating reservoir and stirred to obtain flocculation liquid;

and (3) precipitation treatment: the flocculated liquid is separated in a clarification tank to form a treatment liquid I and sludge I.

4. The desulfurization wastewater bypass flue evaporation treatment process of claim 1, wherein the re-softening treatment comprises:

and (3) magnesium ion removal treatment: putting sodium hydroxide at the front end of the flow direction of the treatment fluid I;

calcium ion removal treatment: adding sodium carbonate at the middle end of the treating fluid I in the flowing direction;

TMF film treatment: and performing TMF membrane treatment on the tail end of the treatment liquid I in the flowing direction to obtain the treatment liquid II and a turbid liquid, and refluxing the turbid liquid to the tail end of the treatment liquid I in the flowing direction to perform TMF membrane treatment.

5. The desulfurization wastewater bypass flue evaporation treatment process as recited in any one of claims 1 to 4, further comprising:

sludge treatment: collecting and treating the sludge I obtained by the primary softening treatment and the sludge II obtained by the secondary softening treatment to obtain sludge cakes and sludge liquid;

and (3) recovery treatment: and after the sludge liquid is recovered and mixed with desulfurization wastewater, sequentially carrying out primary softening treatment, secondary softening treatment, DTRO membrane treatment and bypass flue evaporation treatment.

6. The utility model provides a desulfurization waste water bypass flue evaporation treatment system which characterized in that includes:

a bypass flue evaporation treatment system for performing bypass flue evaporation treatment; the treatment liquid III enters an evaporation tower at the top end of the evaporation tower of the bypass flue evaporation treatment system and is atomized, and high-temperature flue gas entering the evaporation tower from a first bypass flue of boiler flue gas enters the top of the evaporation tower and is subjected to evaporation crystallization treatment to obtain mixed flue gas and sedimentation impurities;

the evaporation tower includes the tower body, and the tower body is equipped with from the top down along its direction of height in proper order: the first flue gas inlet section, the spraying section, the mixed flue gas outlet section and the skirt section; the first flue gas inlet section is provided with a first pipeline for communicating high-temperature flue gas of the first bypass flue; the skirt section is provided with a second pipeline for passing through the high-temperature flue gas of the second bypass flue, and the second pipeline is connected with the first pipeline in parallel; the spraying section is provided with sprayers arranged towards one side of the flue gas outlet section, and the sprayers form a spraying layer; the mixed flue gas outlet section is provided with a third pipeline for flowing out mixed flue gas; the lower end of the skirt section is provided with a fourth pipeline for discharging the settled impurities; a first guide plate is arranged below the spraying layer, the first guide plate is provided with a first side wall and a second side wall which are oppositely arranged, the first side wall is arranged on the inner side wall of the tower body, and the second side wall is inclined upwards; be equipped with the second guide plate between mixed flue gas export section and the skirt section, the second guide plate has relative third lateral wall and the fourth lateral wall that sets up, the third lateral wall sets up in the inside wall of tower body, and is located the below of third pipeline, the fourth lateral wall is slope down.

7. The desulfurization wastewater bypass flue evaporation treatment system of claim 6, characterized in that:

the bypass flue evaporation treatment system also comprises a dust removal device and a pipeline flowing to the desulfurization system; enabling the dust removal device to treat the mixed flue gas to obtain dust and water vapor; and the steam flows to a desulfurization system through the pipeline to supplement water.

8. The desulfurization wastewater bypass flue evaporation treatment system of claim 6, characterized in that:

the primary softening treatment system comprises a first reaction tank for carrying out pH adjustment treatment, and a stirring device is arranged in the first reaction tank; and a clarification tank;

the first reaction tank and the clarification tank are connected in sequence.

9. The desulfurization wastewater bypass flue evaporation treatment system of claim 6, characterized in that:

the re-softening treatment system comprises:

a second reaction tank for performing magnesium ion removal treatment;

a third reaction tank for performing a calcium ion removal treatment; and the number of the first and second groups,

a TMF film device for performing TMF film treatment;

the TMF membrane device comprises a TMF concentration tank, a TMF membrane structure and a reflux pump; the TMF membrane structure is provided with a water inlet pipe, a clear liquid outlet pipe and a turbid liquid outlet pipe;

the second reaction tank, the third reaction tank, the TMF concentration tank, the water inlet pipe, the clear liquid outlet pipe and the DTRO membrane treatment system are sequentially and fluidly connected;

the turbid liquid outlet pipe is fluidly coupled to the TMF concentrator tank by a reflux pump.

10. The desulfurization wastewater bypass flue evaporation treatment system of any one of claims 6-9, further comprising:

a sludge treatment system for performing sludge treatment; the sludge treatment system collects and treats the sludge I obtained by the primary softening treatment system and the sludge II obtained by the secondary softening treatment system to obtain sludge cakes and sludge liquid; and the number of the first and second groups,

and the recovery processing pipeline is used for recovering and processing sludge liquid and returning the sludge liquid to the primary softening processing system.