A desulfurization wastewater evaporation treatment system

Abstract

The present invention discloses an evaporation treatment system for desulfurized wastewater, comprising a main flue unit, the main flue unit comprising an air preheater, a heat exchanger, a dust collector and a wet flue gas desulfurization tower connected in sequence through the main flue; further comprising: a bypass flue unit, the inlet of the bypass flue unit is connected to the main flue upstream of the air preheater, the outlet of the bypass flue unit is connected to the main flue between the heat exchanger and the dust collector, and an atomizing nozzle is arranged in the bypass flue unit; a waterway unit, comprising a first connecting pipe and a second connecting pipe, the heat exchanger has a heat exchange pipe, the first connecting pipe is connected to the wet flue gas desulfurization tower and the heat exchange pipe, and is used to introduce the desulfurized wastewater into the heat exchanger, and the second connecting pipe is connected to the heat exchange pipe and the atomizing nozzle. The above-mentioned evaporation treatment system can improve the atomization degree of the desulfurized wastewater, thereby improving the evaporation rate of the droplet particles, and reducing the risk of hitting the wall and scaling, so as to ensure the normal operation of the equipment, and at the same time can also reduce the floor space.

Description

[0001] This application claims the priority of a Chinese patent filed with the China Patent Office on October 24, 2022, with application number "202211304143.2" and invention name "A flue gas treatment system". Technical Field

[0002] The invention relates to the technical field of flue gas treatment, and in particular to an evaporation treatment system for desulfurization wastewater. Background Art

[0003] In the wet desulfurization process of coal-fired flue gas, in order to maintain the material balance of the slurry circulation system of the desulfurization device, a certain amount of wastewater will be discharged. The wastewater contains a variety of pollutants and needs to be treated before it is discharged. At present, the desulfurization wastewater bypass evaporation process is a relatively good process, which has many advantages such as flexible control, easy maintenance, low energy consumption, and little impact on the main system.

[0004] Please refer to Figure 1 , Figure 1 The present invention is a structural schematic diagram of a specific implementation of an evaporation treatment system for desulfurization wastewater in the prior art.

[0005] like Figure 1 As shown, the evaporation treatment system of desulfurization wastewater includes an air preheater 02, a heat exchanger 03, an electrostatic precipitator 04 and a wet desulfurization tower 05 connected in sequence through a main flue 01 to perform heat exchange, dust removal and desulfurization treatment on the flue gas; and, a smoke inlet is provided at the upstream section of the air preheater 02, a smoke return port is provided at the upstream section of the heat exchanger 03, and a bypass flue 06 is provided between the smoke inlet and the smoke return port to lead out high-temperature bypass flue gas (between 300°C and 400°C). During the operation of the system, the desulfurization wastewater generated by the wet desulfurization tower 05 can be introduced into the nozzle in the bypass flue 06 after being treated by the pretreatment device 07, so as to be atomized and sprayed out, and the wastewater droplets are heated, evaporated and crystallized by the high-temperature flue gas to form dust particles, and then these dust particles can flow into the main flue 01 at the smoke return port and can enter the electrostatic precipitator 04 to be captured.

[0006] Research has found that during the operation of the above-mentioned scheme, the wastewater is not completely atomized, resulting in problems such as difficulty in evaporation of droplets, droplets hitting the wall, and scaling of the flue, which seriously affect the normal use of the equipment.

[0007] Therefore, how to provide a solution to overcome or alleviate the above-mentioned defects is still a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0008] The purpose of the present invention is to provide an evaporation treatment system for desulfurization wastewater, which can improve the atomization degree of desulfurization wastewater, thereby improving the evaporation rate of droplet particles and reducing the risks of wall collision and scaling to ensure the normal operation of the equipment, while also reducing the floor space occupied.

[0009] In order to solve the above technical problems, the present invention provides an evaporation treatment system for desulfurization wastewater, comprising a main flue unit, wherein the main flue unit comprises an air preheater, a heat exchanger, a dust collector and a wet flue gas desulfurization tower connected in sequence through the main flue; and further comprising: a bypass flue unit, wherein the inlet of the bypass flue unit is connected to the main flue upstream of the air preheater, the outlet of the bypass flue unit is connected to the main flue between the heat exchanger and the dust collector, and an atomizing nozzle is arranged in the bypass flue unit; a water channel unit, comprising a first connecting pipe and a second connecting pipe, the heat exchanger having a heat exchange tube, the first connecting pipe connecting the wet flue gas desulfurization tower and the heat exchange tube for introducing the desulfurization wastewater into the heat exchanger, and the second connecting pipe connecting the heat exchange tube and the atomizing nozzle.

[0010] Different from the conventional design, the desulfurized wastewater in the embodiment of the present invention is not directly introduced into the atomizing nozzle, but first passes through the heat exchanger for heating. In this way, the viscosity of the desulfurized wastewater can be reduced, making it easier to be broken and atomized, and the heat demand of the wastewater after evaporation and atomization in the bypass flue unit can be reduced. The two-phase action can increase the evaporation rate of the droplet particles, thereby effectively reducing the risks of incomplete evaporation of the droplet particles, the droplet particles hitting the wall and scaling, which is beneficial to ensure the normal operation of the equipment. At the same time, the above scheme can also make more full use of the heat of the flue gas, and can effectively control the temperature of the flue gas entering the dust collector. Moreover, the design of the water channel unit flowing through the heat exchanger in the embodiment of the present invention utilizes the original equipment space. Compared with the conventional design, it can reduce the space occupied by the water channel unit, thereby reducing the floor space of the desulfurized wastewater evaporation treatment system provided by the present invention.

[0011] In addition, after adopting the embodiment of the present invention, a heat exchanger is added to the part of the main flue unit that is connected in parallel with the bypass flue unit, and the resistance will be relatively large. Accordingly, more flue gas can flow into the bypass flue unit, which can increase the heat supply in the bypass flue unit, which can itself improve the evaporation rate of the droplet particles and can ensure the complete evaporation of the droplet particles to a greater extent, thereby reducing the risks of wall impact and scaling.

[0012] Optionally, the main flue unit includes a first section and a second section arranged at an angle, the first section is provided with the air preheater, the second section has a connecting end connected to the first section, and the heat exchanger is located at the connecting end; the heat exchanger has a shell, and the flow area of ​​the shell is gradually reduced from upstream to downstream.

[0013] Optionally, the shell has a top wall, an inner wall surface of the top wall is a first inclined wall surface, and an angle between the first inclined wall surface and an extension direction of the second section is less than 30 degrees.

[0014] Optionally, the number of the heat exchange tubes gradually decreases from upstream to downstream.

[0015] Optionally, a first ash hopper is disposed at the lower end of the first section, the first ash hopper is disposed with a first ash conveying pipeline, the heat exchanger is disposed with a second ash hopper, the second ash hopper is disposed with a second ash conveying pipeline, and the first ash conveying pipeline and the second ash conveying pipeline are connected.

[0016] Optionally, the bypass flue unit includes an evaporation section, which extends in a vertical direction. The evaporation section is provided with the atomizing nozzle and a guide grille, which is located upstream of the atomizing nozzle. The guide grille has a plurality of guide channels, each of which extends in a vertical direction.

[0017] Optionally, a flow balancing orifice plate is further provided in the evaporation section, and the flow balancing orifice plate is located upstream of the guide grille.

[0018] Optionally, the bypass flue unit further includes an inlet section, which is connected to the top end of the evaporation section, and the inner wall surface of the top wall of the evaporation section is a second inclined wall surface, which gradually inclines downward in a direction away from the inlet section.

[0019] Optionally, the bypass flue unit also includes an outlet section, the outlet section having a connecting section and a discharge section arranged at an angle, the connecting section being connected to the bottom end of the evaporation section, part of the connecting section and the discharge section being located in the main flue between the heat exchanger and the dust collector, and the flue gas flow direction in the discharge section is consistent with the flue gas flow direction in the main flue between the heat exchanger and the dust collector.

[0020] Optionally, the water channel unit further includes a flushing liquid pipe, and the flushing liquid pipe is connected to the second connecting pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of a specific implementation method of the evaporation treatment system of desulfurization wastewater in the prior art;

[0022] Figure 2 A schematic structural diagram of a specific implementation of the evaporation treatment system for desulfurization wastewater provided by the present invention;

[0023] Figure 3 for Figure 2The schematic diagram of the structure of the first and second sections;

[0024] Figure 4 It is a schematic diagram of the structure of the bypass flue unit, the second connecting pipe, and the third flue section;

[0025] Figure 5 Schematic diagram of the structure of the guide grid.

[0026] Figure 1 The reference numerals in the figures are described as follows:

[0027] 01 main flue, 02 air preheater, 03 heat exchanger, 04 electrostatic precipitator, 05 wet desulfurization tower, 06 bypass flue, 07 and treatment device.

[0028] Figure 2-Figure 5 The reference numerals in the figures are described as follows:

[0029] 1 main flue unit, 1a first section, 1b second section, 11 main flue, 111 first flue section,

[0030] 112 second flue section, 112a first ash hopper, 112b first ash conveying pipeline, 113 third flue section,

[0031] 114 fourth flue section, 115 fifth flue section, 12 air preheater, 13 heat exchanger, 131 first inclined wall, 132 second ash hopper, 133 second ash conveying pipeline, 14 dust collector, 15 wet desulfurization tower, 16 first fan;

[0032] 2 bypass flue unit, 21 evaporation section, 211 atomizing nozzle, 212 guide grid, 212a guide channel, 213 flow averaging orifice plate, 214 second inclined wall surface, 22 inlet section, 23 outlet section, 231 connecting section, 232 discharge section, 24 second fan;

[0033] 3 water channel unit, 31 first connecting pipe, 32 second connecting pipe, 33 flushing liquid pipe, 34 compressed air pipe, 35 pretreatment device, 36 water pump. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0035] In the embodiments of the present invention, the terms "first", "second", "third", "fourth", and "fifth" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", "third", "fourth", and "fifth" may explicitly or implicitly include one or more of the features.

[0036] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "connected", "connected" and "connected" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0037] The directional terms mentioned in the embodiments of the present invention, such as "vertical", "horizontal", "up", "down", "top", "bottom", "inside", "outside", etc., are only references to the directions of the drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present invention, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0038] In addition, unless otherwise specified in the present application, the term "several" in the present application refers to two or more than two. When "several" is used to indicate the number of certain components, it does not indicate the relationship between the components in terms of quantity.

[0039] In the description of the embodiments of the present invention, the terms "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0040] Please refer to Figure 2-Figure 5 , Figure 2 This is a structural schematic diagram of a specific implementation of the evaporation treatment system for desulfurization wastewater provided by the present invention. Figure 3 for Figure 2 The schematic diagram of the structure of the first and second sections, Figure 4 It is a schematic diagram of the structure of the bypass flue unit, the second connecting pipe, and the third flue section. Figure 5 Schematic diagram of the structure of the guide grid.

[0041] like Figure 2 As shown, the present invention provides an evaporation treatment system for desulfurization wastewater, which is used to treat sulfur-containing flue gas in the form of coal-fired flue gas, metallurgical flue gas, etc., and includes a main flue unit 1, a bypass flue unit 2 and a water channel unit 3.

[0042] The main flue unit 1 includes an air preheater 12, a heat exchanger 13, a dust collector 14 and a wet flue gas desulfurization tower 15 which are sequentially connected through the main flue 11. The air preheater 12 is used to preheat the air, so as to make full use of the waste heat of the flue gas; the heat exchanger 13 is used to control the temperature and heat exchange of the flue gas to control the temperature of the flue gas entering the dust collector 14, and at the same time, the waste heat of the flue gas can be recovered; the dust collector 14 can be a dust removal component in the form of an electric dust collector, a bag dust collector, a cyclone dust collector, etc., which is used to capture and collect dust in the flue gas; the wet flue gas desulfurization tower 15 is used to desulfurize the flue gas, and the wet flue gas desulfurization tower 15 will produce desulfurization wastewater.

[0043] During the flow of smoke in the main flue unit 1, the power can be provided by the first fan 16, and the first fan 16 can be arranged at any position in the main flue unit 1 as long as it can meet the use requirements. Figure 2 In the embodiment, the first fan 16 can be arranged on the main flue 11 between the dust collector 14 and the wet desulfurization tower 15.

[0044] For ease of description, the embodiment of the present invention can name the main flue 11 at various positions respectively. Specifically, the main flue 11 upstream of the air preheater 12 can be called the first flue section 111, and the main flue 11 between the air preheater 12 and the heat exchanger 13 can be called the second flue section 112, and the main flue 11 between the heat exchanger 13 and the dust collector 14 can be called the third flue section 113, and the main flue 11 between the dust collector 14 and the first fan 16 can be called the fourth flue section 114, and the main flue 11 between the first fan 16 and the wet desulfurization tower 15 can be called the fifth flue section 115.

[0045] The inlet of the bypass flue unit 2 is connected to the main flue 11 upstream of the air preheater 12, and the outlet of the bypass flue unit 2 is connected to the main flue 11 between the heat exchanger 13 and the dust collector 14, that is, the bypass flue unit 2 can be connected to the first flue section 111 and the third flue section 113, and is used to extract the high-temperature flue gas in the first flue section 111. An atomizing nozzle 211 is arranged in the bypass flue unit 2.

[0046] The water circuit unit 3 includes a first connecting pipe 31 and a second connecting pipe 32. The first connecting pipe 31 is directly connected to the wet desulfurization tower 15, and is used to lead out the desulfurization wastewater generated by the wet desulfurization tower 15. The first connecting pipe 31 is also equipped with a pretreatment device 35, which is used to pretreat the desulfurization wastewater to obtain the by-product gypsum; the specific structural form of the pretreatment device 35 is not limited here, and can be determined by referring to relevant technologies, as long as it can meet the actual use requirements. The first connecting pipe 31 can also be equipped with a water pump 36 to provide power for the operation of the water circuit unit 3; it should be understood that the water pump 36 can also be set at other positions of the water circuit unit 3, as long as it can meet the operation requirements of the water circuit unit 3. For example, the water pump 36 can also be set in the second connecting pipe 32.

[0047] The heat exchanger 13 has a heat exchange pipe (not shown in the figure), and the first connecting pipe 31 is also connected to the heat exchange pipe, which is used to introduce the desulfurized wastewater into the heat exchange pipe to exchange heat with the flue gas in the heat exchanger 13, so that the desulfurized wastewater can be heated. The second connecting pipe 32 can connect the heat exchange pipe and the atomizing nozzle 211, and can introduce the heated desulfurized wastewater into the atomizing nozzle 211. The atomizing nozzle 211 can atomize the desulfurized wastewater into droplet particles and spray it into the bypass flue unit 2. Under the action of the high-temperature flue gas in the bypass flue unit 2, the droplet particles can be evaporated to achieve evaporation treatment of the desulfurized wastewater generated by the wet desulfurization tower 15.

[0048] Different from conventional design ( Figure 1 In the scheme in the embodiment of the present invention, the desulfurized wastewater is not directly introduced into the atomizing nozzle 211, but first passes through the heat exchanger 13 for heating. In this way, the viscosity of the desulfurized wastewater can be reduced, making it easier to be broken and atomized, and the heat demand of the wastewater after evaporation and atomization in the bypass flue unit 2 can also be reduced. The two-phase action can increase the evaporation rate of the droplet particles, thereby effectively reducing the risks of incomplete evaporation of the droplet particles, the droplet particles hitting the wall and scaling, which is beneficial to ensure the normal operation of the equipment. At the same time, the above scheme can also make more full use of the heat of the flue gas, and can effectively control the temperature of the flue gas entering the dust collector 14. Moreover, the design of the water channel unit 3 flowing through the heat exchanger 13 in the embodiment of the present invention utilizes the original equipment space. Compared with the conventional design, it can reduce the occupied space of the water channel unit 3, thereby reducing the floor space of the evaporation treatment system of the desulfurized wastewater provided by the present invention.

[0049] In addition, compared Figure 1 and Figure 2It can be found that after adopting the embodiment of the present invention, the part of the main flue unit 1 that is connected in parallel with the bypass flue unit 2 is added with a heat exchanger 13, and the resistance will be relatively large. Accordingly, more flue gas can flow into the bypass flue unit 2, which can increase the heat supply in the bypass flue unit 2, which can also improve the evaporation rate of the droplet particles, and can ensure the complete evaporation of the droplet particles to a greater extent, thereby reducing the risks of wall impact and scaling.

[0050] From another perspective, since the heat demand for evaporating and atomizing wastewater in the bypass flue unit 2 is reduced, and the bypass flue unit 2 can introduce more heat, the bypass flue unit 2 may actually have a heat overflow phenomenon. In this way, when designing the system, the volume of the bypass flue unit 2 has the possibility of being made smaller, which can further reduce the floor space of the evaporation treatment system for desulfurization wastewater provided by the present invention, and thus reduce the cost of the equipment.

[0051] Here, the embodiment of the present invention does not limit the specific structural form, quantity, etc. of the atomizing nozzle 211. In practical applications, those skilled in the art can also set it according to specific needs, as long as it can meet the requirements of use. Exemplarily, the atomizing nozzle 211 can be a two-fluid nozzle. In this case, the waterway unit 3 can include a compressed air pipeline 34 in addition to the second connecting pipe 32 mentioned above, which is used to introduce compressed air into the atomizing nozzle 211 to break up the wastewater particles and form atomization; in addition, the atomizing nozzle 211 can also be a pressure atomizing nozzle, a rotary atomizing nozzle, a bubble atomizing nozzle, etc.

[0052] In some optional embodiments, such as Figure 3 As shown, the main flue unit 1 may include a first section 1a and a second section 1b arranged at an angle; the first section 1a may be provided with an air preheater 12, the second section 1b may have a connection end connected to the first section 1a, and the heat exchanger 13 may be located at the connection end, that is, the heat exchanger 13 may be located at the corner connection between the first section 1a and the second section 1b; the heat exchanger 13 may have a shell, and the flow area of ​​the shell may be gradually reduced from upstream to downstream. The extension direction of the first section 1a and the second section 1b is not limited here. In actual applications, those skilled in the art can design it according to specific needs as long as it can meet the actual use requirements; in Figure 3 In the illustrated embodiment, the first section 1a may extend in a vertical direction, and the second section 1b may extend in a horizontal direction. In this case, the first section 1a and the second section 1b may form an angle of 90 degrees.

[0053] By adopting this scheme, the embodiment of the present invention integrates the corner position of the first section 1a and the second section 1b and the setting position of the heat exchanger 13 in the same area, so that the resistance at the corner position and the resistance of the heat exchanger 13 can be merged in the same area, and then the turning angle of the first section 1a and the second section 1b can be smoothed by the tapered design of the shell of the heat exchanger 13, which can greatly reduce the resistance level in the main flue unit 1, so as to achieve the technical effect of reducing resistance and saving energy; and, through the tapered design of the shell of the heat exchanger 13, the flow rate of the flue gas in the heat exchanger 13 can be controlled within an optimal flow rate window, which can not only improve the heat exchange efficiency of the heat exchanger 13, but also greatly reduce the dust accumulation problem in the heat exchanger 13.

[0054] In addition, compared with the conventional design ( Figure 1 In the embodiment of the present invention, the shell of the heat exchanger 13 omits a flared section, and the structure of the heat exchanger 13 can also be relatively simple.

[0055] The cross-sectional shape of the shell of the heat exchanger 13 can be rectangular. Figure 3 The shell may have a top wall, the inner wall surface of the top wall may be a first inclined wall surface 131, the first inclined wall surface 131 and the extension direction of the second section 1b may be set at an angle to form the aforementioned tapered design, and the top wall may also guide the flue gas in the first section 1a to smooth the turning angle between the first section 1a and the second section 1b, thereby reducing the flow resistance of the flue gas. It should be understood that, under the condition that the top wall of the shell of the heat exchanger 13 is a plate of equal thickness, the entire top wall may be set at an angle to the extension direction of the second section 1b; and under the condition that the top wall is a plate of non-equal thickness, only the structural form of the inner wall surface of the top wall may be limited.

[0056] The size of the angle between the first inclined wall surface 131 and the extension direction of the second section 1b is not limited here. In practical applications, those skilled in the art can design it according to specific needs as long as it can meet the requirements of use. For example, the angle can be set to be less than 30°. In this case, the change of the flow area of ​​the shell is relatively gentle, which is more conducive to reducing the flow resistance, so as to achieve the technical effect of reducing resistance and saving energy.

[0057] It should be understood that the tapered shell constructed by the first inclined wall 131 is only an exemplary description of an embodiment of the present invention, and cannot be used as a limitation on the scope of implementation of the evaporation treatment system for desulfurized wastewater provided by the present invention. Under the condition of satisfying the functions, the tapered shell can also adopt other structural forms. Exemplarily, the cross-section of the shell can be circular, in which case the shell can be a truncated cone structure; or, the first inclined wall 131 can be set not on the top wall of the shell, but on other walls of the shell, as long as the flow area of ​​the shell finally formed presents a tapered design; in addition, the first inclined wall 131 is not limited to a plane, and it can also be a curved surface, such as an arc surface.

[0058] In some optional embodiments, within the shell of the heat exchanger 13, the number of heat exchange tubes may gradually decrease from upstream to downstream.

[0059] It should be understood that the flue gas flow area in the heat exchanger 13 = the flow area of ​​the shell - the blocking area of ​​the heat exchange tube. The more the number of heat exchange tubes, the larger the blocking area of ​​the heat exchange tubes. As mentioned above, the flow area of ​​the shell will gradually decrease from upstream to downstream. On this basis, reducing the number of heat exchange tubes can ensure the consistency of the flue gas flow area in the heat exchanger 13 to a certain extent, and stabilize the flue gas flow rate inside the heat exchanger 13 in the aforementioned preferred flow rate window, so as to improve the heat exchange efficiency and reduce the ash accumulation problem.

[0060] Here, the embodiment of the present invention does not limit the decreasing range of the number of heat exchange tubes. In practical applications, those skilled in the art can determine it in combination with specific usage needs, as long as the corresponding technical effects can be achieved. For example, from upstream to downstream, a plurality of heat exchange tube groups can be arranged in the heat exchanger 13, and the number of heat exchange tubes in the downstream heat exchange tube group can be reduced by 1 to 3 compared with the number of heat exchange tubes in the adjacent heat exchange tube group.

[0061] In some optional embodiments, the lower end of the first section 1a may be provided with a first ash hopper 112a, and the first ash hopper 112a may be provided with a first ash conveying pipeline 112b for discharging dust in the first section 1a; the heat exchanger 13 may be provided with a second ash hopper 132, and the second ash hopper 132 may be provided with a second ash conveying pipeline 133 for discharging dust in the heat exchanger 13, which can effectively avoid or reduce the dust accumulation problem in the heat exchanger 13.

[0062] Furthermore, the first ash conveying pipeline 112b and the second ash conveying pipeline 133 may be connected to improve the integration of the pipelines and facilitate the centralized treatment of dust, while also reducing the cost of adding additional ash conveying pipelines.

[0063] Combination Figure 4The bypass flue unit 2 may include an evaporation section 21 , and the evaporation section 21 may extend in a vertical direction. The aforementioned atomizing nozzle 211 may be specifically arranged in the evaporation section 21 , and the evaporation process of the droplet particles basically occurs in the evaporation section 21 .

[0064] The evaporation section 21 may also be provided with a guide grid 212, which may be located upstream of the atomizing nozzle 211 and is used to guide the flue gas flowing toward the atomizing nozzle 211. Specifically, the guide grid 212 may have a plurality of guide channels 212a, each of which extends in a vertical direction, so that the flue gas also flows in a vertical direction, thereby creating a good flow field condition for the evaporation of the droplet particles, and being able to largely avoid the droplet particles from hitting the inner wall of the evaporation section 21 during the spraying process, thereby reducing the risk of wall impact and scaling.

[0065] The structure of the grid plate 212 can be adjusted as needed, and is not limited here, as long as it can meet the requirements of use. Figure 5 As shown, the ratio of the height H and the spacing L of the guide channels 212a (ie, the grille holes) of the grille plate 212 may be within the following range: H / L<3, so as to improve the verticality of the airflow.

[0066] In some optional embodiments, a flow balancing orifice plate 213 may be further provided in the evaporation section 21 . The flow balancing orifice plate 213 may be located upstream of the guide grid 212 to improve the uniformity of the flow of the flue gas in the evaporation section 21 .

[0067] Similarly, the structural form of the flow balancing orifice plate 213 can also be adjusted as needed, as long as it can meet the requirements of use. For example, the flow balancing orifice plate 213 can be a steel plate with a circular hole, and the diameter of the circular hole can be no greater than 50 mm; of course, the shape of the hole opened by the flow balancing orifice plate 213 is not limited to a circular hole, and a rectangular hole, a triangular hole or other forms of openings can be used.

[0068] Still Figure 4 As shown, the bypass flue unit 2 may also include an inlet section 22, the inlet section 22 and the top end of the evaporation section 21 may be connected, the inner wall surface of the top wall of the evaporation section 21 may be a second inclined wall surface 214, and the second inclined wall surface 214 may gradually tilt downward in a direction away from the inlet section 22 to smooth the turning angle between the inlet section 22 and the evaporation section 21, thereby reducing the flow resistance of the flue gas and achieving the technical effect of reducing resistance and energy saving. It should be understood that, under the condition that the top wall of the evaporation section 21 is a plate of equal thickness, the top wall as a whole may be gradually tilted downward; and under the condition that the top wall is a plate of non-equal thickness, only the structural form of the inner wall surface of the top wall may be limited.

[0069] Similar to the aforementioned first inclined wall surface 131, the second inclined wall surface 214 may also be a plane or a curved surface. When it is a curved surface, the second inclined wall surface 214 may be an arc-shaped surface. The inclination angle of the second inclined wall surface 214 is also not limited here.

[0070] It should be understood that the description of connecting the inlet section 22 and the evaporation section 21 through the second inclined wall 214 is only an exemplary description of the embodiment of the present invention, and cannot be used as a limitation on the scope of implementation of the desulfurization wastewater evaporation treatment system provided by the present invention. Under the condition of meeting the function, the inlet section 22 and the evaporation section 21 can also be connected in other structural forms. For example, the inlet section 22 and the evaporation section 21 can also be connected in a curved pipe + gradually expanding pipe structure. For details, please refer to Figure 1 shown.

[0071] In some optional embodiments, the bypass flue unit 2 may further include an outlet section 23, which may include a connecting section 231 and a discharge section 232 arranged at an angle, the connecting section 231 being connected to the bottom end of the evaporation section 21, specifically, being transitionally connected through a tapered tube; a portion of the connecting section 231 and the discharge section 232 may be located in the third flue section 113, and the flue gas flow direction in the discharge section 232 may be consistent with the flue gas flow direction in the third flue section 113. By adopting this solution, it is possible to largely avoid the flue gas in the bypass flue unit 2 from disturbing the distribution state of the flow field in the third flue section 113, thereby avoiding the dust removal efficiency of the dust collector 14 from being affected by the change in the flow field.

[0072] Similar to the operation of the main flue unit 1, the bypass flue unit 2 can also be operated with the help of a fan. For the sake of distinction, the fan arranged in the bypass flue unit 2 can be referred to as a second fan 24. The second fan 24 can be arranged at any position of the bypass flue unit 2 as long as it can achieve its function. Figure 2 In the embodiment, the second fan 24 may be disposed in the inlet section 22 .

[0073] In some optional embodiments, the water circuit unit 3 may further include a flushing liquid pipe 33, which may be connected to the second connecting pipe 32 to introduce flushing liquid into the atomizing nozzle 211. The flushing liquid may clean the atomizing nozzle 211, thereby reducing the risk of the atomizing nozzle 211 being blocked.

[0074] The composition of the flushing liquid can be selected according to the composition of the desulfurization wastewater. Generally speaking, the flushing liquid can be an acid solution or an alkaline solution. When the system is operating normally, the valve of the flushing liquid pipeline 33 can be in a closed state. When a specific working condition occurs, the valve of the flushing liquid pipeline 33 can be opened to timely introduce the flushing liquid into the atomizing nozzle 211.

[0075] The specific working conditions are not limited here, and can be determined in combination with the actual equipment operation conditions. For example: 1) before the bypass flue unit 2 is shut down and put into use, that is, each time the equipment is started, the atomizing nozzle 211 can be flushed with flushing liquid; 2) when the monitoring variable is abnormal and it is judged that the atomizing nozzle 211 may be blocked, under this working condition, the valve of the desulfurization wastewater can be closed first to prevent the introduction of the desulfurization wastewater, and then the valve of the flushing liquid pipeline 33 can be opened; the monitoring variable can be a parameter such as pressure difference and flow rate.

[0076] In summary, the evaporation treatment system for desulfurization wastewater provided in the embodiment of the present invention adopts a series of complementary and mutually reinforcing measures, which can greatly reduce the risks of clogging of the atomizing nozzle 211, droplet impact on the wall, flue scaling, as well as dust accumulation in the heat exchanger 13, insufficient bypass flue gas extraction and other problems. At the same time, the system occupies a smaller area and the system operation is more stable, which has achieved significant technical progress compared with the existing technology.

[0077] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A desulfurization wastewater evaporation treatment system, comprising a main flue unit (1), wherein the main flue unit (1) comprises an air preheater (12), a heat exchanger (13), a dust collector (14) and a wet desulfurization tower (15) connected in sequence through a main flue (11), characterized in that: Also includes: A bypass flue unit (2), wherein an inlet of the bypass flue unit (2) is connected to the main flue (11) upstream of the air preheater (12), an outlet of the bypass flue unit (2) is connected to the main flue (11) between the heat exchanger (13) and the dust collector (14), and an atomizing nozzle (211) is provided in the bypass flue unit (2); The water channel unit (3) comprises a first connecting pipe (31) and a second connecting pipe (32), the heat exchanger (13) having a heat exchange pipe, the first connecting pipe (31) connecting the wet desulfurization tower (15) and the heat exchange pipe, and used for introducing desulfurization wastewater into the heat exchanger (13), and the second connecting pipe (32) connecting the heat exchange pipe and the atomizing nozzle (211); The main flue unit (1) comprises a first section (1a) and a second section (1b) which are arranged at an angle, the first section (1a) being provided with the air preheater (12), the second section (1b) having a connection end connected to the first section (1a), and the heat exchanger (13) being located at the connection end; the heat exchanger (13) having a shell, the flow area of ​​which is gradually reduced from upstream to downstream; the shell having a top wall, the inner wall surface of which is a first inclined wall surface (131), the angle between the first inclined wall surface (131) and the extension direction of the second section (1b) being less than 30 degrees; and the number of the heat exchange tubes gradually decreases from upstream to downstream.

2. The evaporation treatment system for desulfurization wastewater according to claim 1, characterized in that: The lower end of the first section (1a) is provided with a first ash hopper (112a), the first ash hopper (112a) is provided with a first ash conveying pipeline (112b), the heat exchanger (13) is provided with a second ash hopper (132), the second ash hopper (132) is provided with a second ash conveying pipeline (133), and the first ash conveying pipeline (112b) and the second ash conveying pipeline (133) are connected.

3. The evaporation treatment system for desulfurization wastewater according to claim 1 or 2, characterized in that: The bypass flue unit (2) comprises an evaporation section (21), the evaporation section (21) extending in a vertical direction, the evaporation section (21) being provided with the atomizing nozzle (211) and a guide grille (212), the guide grille (212) being located upstream of the atomizing nozzle (211), the guide grille (212) having a plurality of guide channels (212a), each of the guide channels (212a) extending in a vertical direction.

4. The evaporation treatment system for desulfurization wastewater according to claim 3 is characterized in that: A flow balancing orifice plate (213) is also provided in the evaporation section (21), and the flow balancing orifice plate (213) is located upstream of the guide grid (212).

5. The evaporation treatment system for desulfurization wastewater according to claim 3 is characterized in that: The bypass flue unit (2) further comprises an inlet section (22), wherein the inlet section (22) is connected to the top end of the evaporation section (21), and the inner wall surface of the top wall of the evaporation section (21) is a second inclined wall surface (214), and the second inclined wall surface (214) gradually inclines downward in a direction away from the inlet section (22).

6. The evaporation treatment system for desulfurization wastewater according to claim 3 is characterized in that: The bypass flue unit (2) further comprises an outlet section (23), the outlet section (23) comprising a connecting section (231) and a discharge section (232) arranged at an angle, the connecting section (231) being connected to a bottom end of the evaporation section (21), a portion of the connecting section (231) and the discharge section (232) being located in the main flue (11) between the heat exchanger (13) and the dust collector (14), and a flue gas flow direction in the discharge section (232) being consistent with a flue gas flow direction in the main flue (11) between the heat exchanger (13) and the dust collector (14).

7. The evaporation treatment system for desulfurization wastewater according to claim 1 or 2, characterized in that: The water channel unit (3) further comprises a flushing liquid pipeline (33), wherein the flushing liquid pipeline (33) is connected to the second connecting pipeline (32).

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