A method for treating limestone desulfurization wastewater

Abstract

The application discloses a limestone desulfurization wastewater treatment method, which is based on a high-temperature evaporation treatment process of conventional desulfurization wastewater, and two smoke flows are formed from high-temperature flue gas; dust in one smoke flow is compressed and then introduced into a desulfurization wastewater inlet pipe, so that the initial temperature of the desulfurization wastewater entering an evaporation tower is increased, and the downward diffusion degree of mist drops is increased under the flow assisting effect of the flue gas; the other smoke flow is transported to different positions downward in the evaporation tower and then flows upward to contact the mist drops under the synergistic effect of a flue gas diffusion mechanism and a flow guide structure in the evaporation tower, so that the diffusion direction of the smoke flow is controlled, and heat medium transmission is effectively performed; efficient dispersion contact between the flue gas and the mist drops is realized, the evaporation effect is improved, evaporation of the insufficiently reacted mist drops descending is realized, in addition, a plurality of rotating heat transfer scrapers are matched, one aspect is to rotate and stir the flue gas and the mist drops in the countercurrent contact, and the other aspect is to scrape off the crystals.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment, more particularly to a limestone desulfurization wastewater treatment method. BACKGROUND

[0002] In the limestone-gypsum flue gas desulfurization process, in order to maintain the material balance of the slurry circulating system of the desulfurization device, prevent the soluble part in the flue gas, i.e. the chloride ion concentration, from exceeding the specified value, and ensure the quality of gypsum, a certain amount of wastewater needs to be discharged from the system. These wastewaters mainly come from gypsum dewatering and cleaning systems. Limestone-gypsum flue gas desulfurization wastewater is relatively complex in composition, mainly including suspended solids, supersaturated sulfites, sulfates, and heavy metals, etc.

[0003] Traditional desulfurization wastewater zero discharge mainly has two methods. One method is to directly pass the desulfurization wastewater into the original flue gas duct for evaporation. The other method is to separately set up a wastewater evaporation system, and introduce the desulfurization wastewater into a separately set evaporation tower device for water evaporation. For example, patent No. CN109650476A discloses a desulfurization wastewater zero discharge system and method. Compressed air and desulfurization wastewater are introduced into a double-fluid spray gun for atomization, and are evaporated by hot flue gas in an evaporation furnace. The mixed flue gas after evaporation is dusted by a cyclone dust collector, and then flows out of the bypass system.

[0004] That is, in the prior art, the wastewater is only sprayed into a high-temperature evaporation device, and the flue gas moves from bottom to top. It is difficult to control the flue gas distribution, so it is difficult to achieve uniform and sufficient contact between the wastewater and the flue gas in a large treatment space, which affects the evaporation effect of the wastewater. Even some wastewater cannot be completely evaporated and enters the electric dust collector with the dust or falls with the crystalline body. Especially for high-temperature flue gas that has not gone through the dust removal process, the flue gas contains a large amount of dust particles. The water vapor in the evaporation process increases the gravity and viscosity of the ash in the flue gas, which will seriously accumulate ash and crystallize on the wall surface of the evaporation device and the support. Eventually, the dust collector and the inner wall of the evaporation device are seriously scaled and corroded. SUMMARY

[0005] The present application aims to solve the existing problems and provides a limestone desulfurization wastewater treatment method compared with the prior art.

[0006] The purpose of the present application can be achieved by the following technical scheme: a limestone desulfurization wastewater treatment method, comprising the following steps:

[0007] S1, wastewater atomization spraying: introducing the desulfurization wastewater into the atomizer at the top of the evaporation tower through the desulfurization wastewater inlet pipe to form an atomization spraying environment from top to bottom;

[0008] S2, flue gas split processing: using flue gas split processing device to divide high temperature flue gas into two flows, one directly into the evaporation tower from the top, and the other mixed with desulfurization wastewater after dust removal and pressurization and then sprayed downward by the atomizer after being atomized by the atomizer;

[0009] S3, evaporation and concentration processing: the flue gas entering from the top of the evaporation tower enters the flue gas diffusion mechanism, most of the flue gas overflowing from the bottom gas outlet of the evaporation ball diffuses uniformly upward along the guide surface in the guide structure, and a small part of the flue gas overflowing from the bottom end of the guide pipe moves upward to evaporate the desulfurization wastewater droplets that have not fully reacted;

[0010] In this process, a plurality of heat transfer wipers distributed annularly on the inner side of the guide structure are started to make rotary scraping actions on the evaporation ball and the inner end wall of the guide structure, which on the one hand rotates and stirs the flue gas and the droplets in countercurrent contact, and on the other hand scrapes off the generated crystals;

[0011] S4, flue gas exhaust processing: the steam is discharged into the second dust removal of the electric precipitator through the steam discharge pipe along with the cooling flue gas, and then discharged from the chimney after being treated by the condensing device;

[0012] S5, waste discharge processing: the generated crystals are scraped downward by the heat transfer wiper and continuously discharged along the guide structure and the discharge inclined pipe.

[0013] Further, the flue gas split processing device comprises a flue gas inlet pipe connected to the original flue gas duct, the other end of the flue gas inlet pipe is connected with a flue gas branch pipe one and a flue gas branch pipe two, the other end of the flue gas branch pipe one is directly connected to the top of the evaporation tower, the other end of the flue gas branch pipe two is connected to the electric precipitator one, the air compressor is connected to the air outlet of the electric precipitator one, and the air compressor is connected to the air outlet of the air compressor.

[0014] Further, the atomizer comprises a fixed plate fixedly installed on the top of the evaporation tower, the fixed plate is provided with an annular pipe connected with the lower end of the desulfurization wastewater inlet pipe, and a plurality of atomizing nozzles penetrating through the fixed plate below are annularly distributed on the lower end of the annular pipe.

[0015] Further, the guide structure comprises a guide seat fixedly installed inside the evaporation tower below the evaporation ball, and a discharge straight pipe extending downward is fixed to the bottom end of the guide seat.

[0016] Further, the upper end of the evaporation ball is provided with a connecting pipe fixedly installed on the fixed plate and connected with the flue gas branch pipe one, an inner heating cavity and an outer heat conduction cavity are arranged inside the evaporation ball, and the upper and lower ends of the outer heat conduction cavity are connected with the connecting pipe and the bottom gas outlet of the evaporation ball respectively.

[0017] Further, the upper end of the flow guide pipe is fixedly installed at the gas outlet of the evaporation ball, and the lower end extends to the bottom of the discharge straight pipe, the top end of the flow guide pipe is provided with an upper gas inlet communicated with the gas outlet, and the bottom end of the flow guide pipe is provided with a plurality of downward inclined lower gas outlets.

[0018] Further, the heat transfer blade includes a lower blade body rotatably installed in the discharge straight pipe and movably arranged on the outer wall of the flow guide pipe, and the upper end of the lower blade body is fixedly provided with an upper blade body matched with the inner wall of the guide seat and the outer wall structure of the evaporation ball.

[0019] Further, the top end of the discharge straight pipe is rotatably embedded with a rotating gear ring fixedly connected with the outer walls of the plurality of lower blade bodies, and the bottom end of the evaporation tower is rotatably driven to be provided with a rotating gear engaged with the rotating gear ring.

[0020] Compared with the prior art, the advantages of the present application are:

[0021] The present application is based on the conventional high-temperature evaporation treatment process of desulfurization wastewater, and the high-temperature flue gas is divided into two streams, one stream is compressed after dust removal and introduced into the desulfurization wastewater inlet pipe, which not only increases the initial temperature of the desulfurization wastewater entering the evaporation tower, but also increases the degree of downward diffusion of the droplets under the action of the flue gas flow, and the other stream is transported to different positions in the evaporation tower and then flows upward to contact with the desulfurization wastewater spray, which not only controls the diffusion direction of the flue gas, but also serves as a heat transfer surface for heat medium transfer, effectively realizing the efficient dispersion of flue gas around the evaporation ball and the uniform contact of the downward sprayed droplets, improving the evaporation effect, and realizing the evaporation of a small amount of downward flue gas after upward flow to the downward desulfurization wastewater droplets that have not been fully reacted.

[0022] In addition, a plurality of groups of heat transfer blades are rotatably driven inside the flow guide structure, which rotate and scrape the evaporation ball and the inner end wall of the flow guide structure, on the one hand, the heat transfer blades rotate and stir the upward and downward countercurrently contacted flue gas and droplets, promote the heat exchange between the flue gas and the droplets by the heat transfer of the evaporation ball and the plurality of upper blade bodies, and accelerate the evaporation and crystallization, on the other hand, the heat transfer blades scrape off the crystals attached to the evaporation ball and the inner wall of the flow guide structure, which is not easy to scale. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The flow chart of the method of the present application is shown in the figure;

[0024] Figure 2 The structure diagram of the device related to the present application is shown in the figure;

[0025] Figure 3 The partial sectional view of the evaporation tower of the present application is shown in the figure;

[0026] Figure 4It is a bottom view of the flue gas diffusion mechanism of the present application.

[0027] Figure 5 It is a whole sectional view in the evaporation tower of the present application.

[0028] Figure 6 It is a structural schematic diagram of the heat transfer blade of the present application.

[0029] Figure 7 It is a sectional view in the evaporation tower during the high-temperature evaporation treatment process of the present application.

[0030] Explanation of figure mark:

[0031] 1, evaporation tower; 101, outer straight tube; 102, discharge inclined pipe; 2, flue gas inlet pipe; 201, flue gas branch pipe one; 202, flue gas branch pipe two; 3, electric dust collector one; 4, air compressor; 401, flow guide pipe; 5, desulfurization wastewater inlet pipe; 501, atomizing nozzle; 6, fixed plate; 7, evaporation ball; 701, connecting pipe; 702, outer heat conduction cavity; 8, flow guide seat; 9, heat transfer blade; 91, upper blade body; 92, lower blade body; 10, discharge straight pipe; 11, flow guide pipe; 111, upper air inlet; 112, lower air outlet; 12, steam discharge pipe; 13, electric dust collector two; 14, condensing device; 15, chimney. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application; obviously, the described embodiments are only part of the embodiments of the present application, but not all the embodiments; based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0033] Embodiment 1: The present scheme is aimed at the difficulty in controlling the flue gas distribution in the high-temperature flue gas evaporation process of the desulfurization wastewater in the prior art, so that the wastewater and the flue gas cannot be uniformly and fully contacted in a large treatment space, which affects the evaporation effect of the wastewater, and even part of the wastewater cannot be completely evaporated and enters the dust collector or falls with the crystalline body, and the following technical scheme is proposed:

[0034] The present application discloses a treatment method for limestone desulfurization wastewater, please refer to Figures 1-7 , including the following steps:

[0035] S1, waste water atomization spraying: first, add lime milk solution to waste water to neutralize and adjust pH value, then add organic sulfur, coagulant and coagulant aid to waste water to promote heavy metals, suspended solids and other impurities to precipitate, finally, through clarification, concentration and pressure filtration dewatering, the separation of sludge and waste water is realized, and the pretreated desulfurization waste water is obtained, the desulfurization waste water is introduced into the atomizer at the top of the evaporation tower 1 through the desulfurization waste water inlet pipe 5, and the atomization spraying environment is formed from top to bottom;

[0036] S2, flue gas split processing: the flue gas split processing device is used to split the high-temperature flue gas into two streams, one of which is directly introduced into the evaporation tower 1 at the top, and the other of which is introduced into the desulfurization waste water inlet pipe 5 after dust removal and pressure increase, and is mixed with the desulfurization waste water and sprayed downward by the atomizer;

[0037] S3, evaporation and concentration processing: the flue gas introduced from the top of the evaporation tower 1 enters the flue gas diffusion mechanism, most of the flue gas flows out from the bottom of the evaporation ball 7 and diffuses upward along the inner guide surface of the guide structure below the evaporation ball 7, and a small part of the flue gas enters the guide pipe 11 from the bottom of the evaporation ball 7 and flows out from the bottom of the guide pipe 11 and moves upward to evaporate the desulfurization waste water droplets that have not been fully reacted;

[0038] In this process, a plurality of groups of heat transfer wipers 9 distributed in the inner side of the guide structure are started, and the heat transfer wipers 9 are used to rotate and scrape the evaporation ball 7 and the inner end wall of the guide structure, on the one hand, the flue gas and the droplets in counter-current contact are rotated and stirred, and on the other hand, the crystals attached to the evaporation ball 7 and the inner wall of the guide structure are scraped downward;

[0039] S4, flue gas exhaust processing: the evaporated steam is discharged into the electric precipitator 2 13 through the steam discharge pipe 12 along with the cooling flue gas, and the steam pollutants are removed together with the dust in the original flue gas in the electric precipitator 2 13, and then treated by the condensing device 14 and discharged from the chimney 15;

[0040] S5, waste material exhaust processing: the water vapor in the evaporation process increases the gravity and viscosity of the ash in the flue gas, causing the dust particles to adhere to the crystals, which are discharged along the guide structure at the bottom of the evaporation tower 1 and the discharge inclined pipe 102 under the rotation of the outer heat transfer wipers 9.

[0041] Example 2: The flue gas split processing device involved in the processing method of example 1 is described in detail as follows:

[0042] Please refer to Figure 2 , Figure 3The flue gas shunt treatment device comprises a flue gas inlet pipe 2 connected with the original flue, a flue gas branch pipe one 201 and a flue gas branch pipe two 202 connected with the other end of the flue gas inlet pipe 2, the other end of the flue gas branch pipe one 201 directly leading to the top of the evaporation tower 1, the other end of the flue gas branch pipe two 202 leading to the electric dust collector one 3, the air compressor 4 connected with the exhaust port of the electric dust collector one 3, the air compressor 4 connected with the air outlet and the desulfurization wastewater inlet pipe 5, the atomizer comprising a fixed plate 6 fixedly installed at the top of the evaporation tower 1, the fixed plate 6 being provided with a ring-shaped pipe connected with the lower end of the desulfurization wastewater inlet pipe 5, and a plurality of atomizing nozzles 501 penetrating through the lower portion of the fixed plate 6 being annularly distributed at the lower end of the ring-shaped pipe;

[0043] The high-temperature flue gas is divided into two flue streams, one directly passing through the flue gas branch pipe one 201 into the top of the evaporation tower 1 and being connected with the flue gas diffusion mechanism inside the evaporation tower 1, and the other passing through the dust removal and pressure increase and then being mixed with the desulfurization wastewater in the desulfurization wastewater inlet pipe 5 and being atomized by the plurality of atomizing nozzles 501 on the atomizer and then being sprayed downward, which on one hand improves the initial temperature of the desulfurization wastewater entering the evaporation tower 1 and preheats for subsequent evaporation and concentration, and on the other hand improves the atomization degree after pressure increase, and improves the downward spraying and diffusion degree of the mist droplets under the action of the flue gas, so as to further realize the uniform and sufficient contact between the wastewater and the flue gas.

[0044] Please refer to Figure 3 The guide structure comprises a guide seat 8 fixedly installed inside the evaporation tower 1 and located below the evaporation ball 7, the guide seat 8 being in a hollow conical structure with the upper portion being wide and the lower portion being narrow, the guide seat 8 being fixedly provided with a downwardly extending discharge straight pipe 10 at the bottom end, the bottom of the evaporation tower 1 being in a bucket-shaped structure with the upper portion being wide and the lower portion being narrow, the evaporation tower 1 being fixedly provided with an outer straight cylinder pipe 101 located outside the discharge straight pipe 10 and serving to fixedly install the discharge straight pipe 10, and the discharge straight pipe 10 being fixedly connected with a discharge inclined pipe 102 penetrating through the outside of the outer straight cylinder pipe 101 and being arranged in an inclined downward manner.

[0045] Please refer to Figures 3-7The flue gas diffusion mechanism is composed of the evaporation ball 7 and the flow guide pipe 11 below. The upper end of the evaporation ball 7 is provided with a connecting pipe 701 fixedly installed on the fixed plate 6 and connected with the flue gas branch pipe one 201. The inside of the evaporation ball 7 is provided with an inner heating cavity and an outer heat conduction cavity 702 distributed inside and outside. The upper and lower ends of the outer heat conduction cavity 702 are respectively connected with the connecting pipe 701 and the gas outlet at the bottom end of the evaporation ball 7. A heater is installed in the heating cavity for controlling the evaporation environment temperature inside the evaporation ball 7 and the evaporation tower 1. The upper end of the flow guide pipe 11 is fixedly installed at the gas outlet of the evaporation ball 7, and the lower end extends to the bottom of the discharge straight pipe 10. The top end of the flow guide pipe 11 is provided with an upper air inlet 111 connected with the gas outlet. The bottom end of the flow guide pipe 11 is provided with a plurality of downwardly inclined lower air outlets 112. The evaporation ball 7, the inner wall of the evaporation tower 1 and the inner wall of the flow guide seat 8 form a main evaporation space. A plurality of atomizing nozzles 501 are arranged in a ring shape above the main evaporation space.

[0046] The high-temperature flue gas directly introduced into the top of the evaporation tower 1 by the flue gas inlet pipe 2 and the flue gas branch pipe one 201 is introduced into the outer heat conduction cavity 702 through the connecting pipe 701. The outer heat conduction cavity 702 is a hollow circular ring surface for efficiently diffusing the high-temperature flue gas inside the evaporation ball 7 and transferring heat to the outer surface of the evaporation ball 7. Most of the high-temperature flue gas is discharged through the gas outlet at the bottom end of the evaporation ball 7 and diffused upward to the main evaporation space under the flow guiding action of the flow guide seat 8 and the outer circular end surface of the evaporation ball 7. The flue gas diffusion direction is effectively controlled, so that the upward diffusion and downward injection of the water mist in the effective space are bidirectionally impacted and contacted, and the heat exchange and evaporation effect is improved.

[0047] A small amount of flue gas enters the flow guide pipe 11 through the upper air inlet 111 on the flow guide pipe 11, moves downward in the flow guide pipe 11 for a distance, and then overflows through the lower air outlets 112 and moves upward along the inner wall of the discharge straight pipe 10. The evaporation ball 7, the flow guide pipe 11, the flow guide seat 8 and the discharge straight pipe 10 are all made of heat-conducting materials. The inner diameter of the discharge straight pipe 10 is much smaller than the opening diameter of the upper end of the flow guide seat 8. A small amount of flue gas is introduced into the discharge straight pipe 10 from the flow guide pipe 11, and then moves upward from the lower end of the discharge straight pipe 10. The discharge straight pipe 10 serves as a secondary evaporation space, reduces heat loss in a limited space, dries and evaporates a small amount of desulfurization wastewater mist that has not been fully reacted, and reduces the humidity of the crystal. Therefore, the crystal attached to the end wall of the support can be easily scraped off during the rotation of the plurality of heat transfer scrapers 9.

[0048] The structure and driving mode of the heat transfer scraper 9 are described in detail as follows:

[0049] Please refer to Figures 5-7The heat transfer blade 9 comprises a lower blade body 92 rotatably installed inside the discharge straight pipe 10 and movably attached to the outer wall of the flow guide pipe 11, and the upper blade body 91 is fixed to the upper end of the lower blade body 92 and is matched with the inner wall of the flow guide seat 8 and the outer wall structure of the evaporation ball 7. A rotating gear ring is rotatably embedded and installed at the inner side of the top end of the discharge straight pipe 10 and is fixedly connected with the outer wall of the plurality of lower blade bodies 92. A rotating gear is rotatably driven and installed at the bottom end of the evaporation tower 1 and is engaged with the rotating gear ring. A driving motor is installed on the side wall of the bottom end of the evaporation tower 1 and is used to rotate the rotating gear.

[0050] A plurality of heat transfer blades 9 are annularly distributed between the flue gas diffusion mechanism and the flow guide structure. The driving motor is started, and the plurality of heat transfer blades 9 rotate along the axis of the evaporation tower 1 to perform a rotating stirring action. On the one hand, the rotating stirring action stirs the flue gas and the mist droplets in countercurrent contact, promotes the impact contact between them, effectively prolongs the treatment time of the high-temperature flue gas, and promotes the heat exchange between the flue gas and the mist droplets by using the heat transfer of the evaporation ball 7 and the plurality of upper blade bodies 91 to accelerate the evaporation and crystallization. On the other hand, the rotating stirring action is regarded as a rotating scraping action, which scrapes the crystals attached to the inner walls of the evaporation ball 7, the flow guide pipe 11, the flow guide seat 8, and the discharge straight pipe 10. The scraped crystals are not easy to scale and are discharged from the discharge inclined pipe 102.

[0051] In summary, based on the conventional high-temperature evaporation treatment process of desulfurization wastewater, the high-temperature flue gas is divided into two streams. For one stream, the dust-removed and compressed flue gas is mixed with the desulfurization wastewater into the evaporation tower 1. On the one hand, the initial temperature of the desulfurization wastewater entering the evaporation tower 1 is increased. On the other hand, the atomization degree is increased after being pressurized, and the downward diffusion degree of the mist droplets is increased under the action of the flue gas flow, thereby further realizing the uniform and sufficient contact between the wastewater and the flue gas.

[0052] For the other stream, the flue gas diffusion mechanism composed of the evaporation ball 7 and the flow guide pipe 11 is added inside the evaporation tower 1 to transport the flue gas to different positions downward and then upward to contact with the desulfurization wastewater spray. The heat transfer blade 9 is the main flue gas transport, which not only controls the diffusion direction of the flue gas but also serves as a heat transfer surface to transfer heat. It effectively realizes the uniform contact of the flue gas with the mist droplets that are efficiently dispersed around the evaporation ball 7 and efficiently injected downward, thereby improving the evaporation effect and realizing the evaporation of the insufficiently reacted desulfurization wastewater mist droplets after the upward reflux of a small amount of downward flue gas.

[0053] In addition, a plurality of rotatable heat transfer blades 9 are arranged inside the flow guide structure. The heat transfer blades 9 perform a rotating scraping action on the evaporation ball 7 and the inner end wall of the flow guide structure. On the one hand, the rotating stirring action stirs the flue gas and the mist droplets in countercurrent contact, promotes the heat exchange between the flue gas and the mist droplets by using the heat transfer of the heat transfer blades 9 and the plurality of upper blade bodies 91 to accelerate the evaporation and crystallization. On the other hand, the rotating stirring action is regarded as a rotating scraping action, which scrapes the crystals attached to the evaporation ball 7 and the inner wall of the flow guide structure. The scraped crystals are not easy to scale.

[0054] The above merely preferred embodiments of the present application are only used for the purpose of description and illustration. It should not be taken that the present application is limited thereto. Any modifications, equivalent replacements or changes based on the technical scope disclosed by the present application and the improvement concepts thereof should be covered in the protection scope of the present application.

Claims

1. A method for treating limestone desulfurization wastewater, characterized by: The method comprises the following steps: S1, wastewater atomization spraying: the desulfurization wastewater is introduced into the atomizer at the top of the evaporation tower by the desulfurization wastewater inlet pipe to form an atomization spraying environment from top to bottom; S2, flue gas split processing: the high-temperature flue gas is split into two streams by the flue gas split processing device, one of which is directly introduced into the evaporation tower from the top, and the other is mixed with the desulfurization wastewater after dust removal and pressure increase, and then sprayed downward after atomization by the atomizer; S3, evaporation and concentration processing: the flue gas introduced from the top of the evaporation tower enters the flue gas diffusion mechanism, most of the flue gas flows out from the bottom of the evaporation ball and is uniformly diffused upward along the guide surface in the guide structure, and a small amount of flue gas flows out from the bottom of the guide pipe and moves upward to evaporate the desulfurization wastewater droplets that have not fully reacted; In this process, a plurality of heat transfer wipers distributed annularly inside the guide structure are started to make rotary scraping actions on the evaporation ball and the inner end wall of the guide structure, which rotates and stirs the flue gas and the droplets in countercurrent contact, and scrapes off the generated crystals; S4, flue gas exhaust processing: the steam is discharged into the second electrostatic precipitator through the steam discharge pipe along with the cooled flue gas, and then discharged from the chimney after treatment by the condensing device; S5, waste discharge processing: the generated crystals are scraped downward by the heat transfer wiper and continuously discharged along the guide structure and the discharge inclined pipe.

2. A method of treating limestone desulfurization wastewater according to claim 1, characterized in that: The flue gas split processing device comprises a flue gas inlet pipe connected with the original flue gas duct, and the other end of the flue gas inlet pipe is connected with a flue gas branch pipe one and a flue gas branch pipe two, and the other end of the flue gas branch pipe one is directly connected with the top of the evaporation tower; The other end of the flue gas branch pipe two is connected with the first electrostatic precipitator, the air compressor is connected with the air outlet of the first electrostatic precipitator, and the air outlet of the air compressor is connected with the drainage pipe connected with the desulfurization wastewater inlet pipe.

3. A method of treating limestone desulfurization wastewater according to claim 2, characterized in that: The atomizer comprises a fixed plate fixedly installed at the top of the evaporation tower, and the fixed plate is provided with an annular pipe connected with the lower end of the desulfurization wastewater inlet pipe, and a plurality of atomizing nozzles penetrating through the fixed plate below are annularly distributed at the lower end of the annular pipe.

4. A method of treating limestone desulphurisation wastewater according to claim 3, characterised in that: The guide structure comprises a guide seat fixedly installed inside the evaporation tower below the evaporation ball, and a discharge straight pipe is fixedly installed at the bottom end of the guide seat and extends downward.

5. A method of treating limestone desulphurisation wastewater according to claim 4, characterised in that: The upper end of the evaporation ball is provided with a connecting pipe fixedly installed on the fixed plate and connected with the flue gas branch pipe one, and the inside of the evaporation ball is provided with an inner heating cavity and an outer heat conduction cavity distributed inside and outside, and the upper and lower ends of the outer heat conduction cavity are respectively connected with the connecting pipe and the bottom gas outlet of the evaporation ball.

6. A method of treating limestone desulphurisation wastewater according to claim 5, characterised in that: The upper end of the guide pipe is fixedly installed at the gas outlet of the evaporation ball, and the lower end extends to the bottom of the discharge straight pipe, the top end of the guide pipe is provided with an upper gas inlet connected with the gas outlet, and the bottom end of the guide pipe is provided with a plurality of downward inclined lower gas outlets.

7. A method of treating limestone desulphurisation wastewater according to claim 6, characterised in that: The heat transfer wiper comprises a lower piece body rotatably installed inside the discharge straight pipe and movably arranged with the outer wall of the guide pipe, and the upper end of the lower piece body is fixedly provided with an upper piece body matched with the inner wall of the guide seat and the outer wall structure of the evaporation ball.

8. A method of treating limestone desulphurisation wastewater according to claim 7, characterised in that: The top end of the discharge straight pipe is rotatably embedded with a rotating gear ring fixedly connected with the outer walls of a plurality of lower piece bodies, and a rotating gear is rotatably driven and installed at the bottom end of the evaporation tower and engaged with the rotating gear ring.

Images