CN115597078A - Flue gas treatment system - Google Patents

Abstract

The invention discloses a flue gas treatment system, which comprises a main flue unit, wherein the main flue unit comprises an air preheater, a heat exchanger, a dust remover and a wet desulphurization tower which are sequentially connected through a main flue; further comprising: the inlet of the bypass flue unit is communicated with the main flue at the upstream of the air preheater, the outlet of the bypass flue unit is communicated with the main flue between the heat exchanger and the dust remover, and an atomizing nozzle is arranged in the bypass flue unit; the water path unit comprises a first communicating pipeline and a second communicating pipeline, the heat exchanger is provided with a heat exchange tube, the first communicating pipeline is communicated with the wet desulphurization tower and the heat exchange tube, and is used for guiding desulphurization waste water into the heat exchanger, and the second communicating pipeline is communicated with the heat exchange tube and the atomizing nozzle. Above-mentioned flue gas processing system can promote desulfurization waste water's atomization degree, and then can promote the evaporation rate of droplet granule to reduce the risk of bumping wall, scale deposit, in order to guarantee the normal operating of equipment, can also reduce area simultaneously.

Description

Flue gas treatment system

Technical Field

The invention relates to the technical field of flue gas treatment, in particular to a flue gas treatment system.

Background

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 apparatus, a certain amount of wastewater containing various pollutants is discharged and needs to be treated before being discharged. At present, the desulfurization waste water bypass evaporation process is a relatively good process, and has the advantages of flexible control, easiness in maintenance, low energy consumption, small influence on a main system and the like.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an embodiment of a flue gas treatment system in the prior art.

As shown in fig. 1, the flue gas treatment system comprises an air preheater 02, a heat exchanger 03, an electric dust collector 04 and a wet desulphurization tower 05 which are sequentially connected through a main flue 01 so as to perform heat exchange, dust removal and desulphurization treatment on the flue gas; and the upstream section of the air preheater 02 is provided with a smoke taking port, the upstream section of the heat exchanger 03 is provided with a smoke returning port, and a bypass flue 06 is arranged between the smoke taking port and the smoke returning port and is used for leading out high-temperature bypass smoke (between 300 ℃ and 400 ℃). In the operation process of the system, desulfurization wastewater generated by the wet desulfurization tower 05 can be introduced into a nozzle in the bypass flue 06 after being treated by the pretreatment device 07 to be atomized and sprayed out, wastewater fog drops form dust particles after being heated, evaporated and crystallized by high-temperature flue gas, and then the dust particles can flow into the main flue 01 at the smoke return port and can enter the electric dust collector 04 to be collected.

Researches show that in the operation process of the scheme, the problems of difficulty in fog drop evaporation, fog drop wall collision, flue scaling and the like caused by incomplete wastewater atomization are solved, and the normal use of equipment is seriously influenced.

Therefore, how to provide a solution to overcome or alleviate the above drawbacks still remains a technical problem to be solved by those skilled in the art.

Disclosure of Invention

The invention aims to provide a flue gas treatment system which can improve the atomization degree of desulfurization wastewater, further improve the evaporation rate of fog drop particles, reduce the risks of wall collision and scaling, ensure the normal operation of equipment and reduce the occupied area.

In order to solve the technical problem, the invention provides a flue gas treatment system which comprises a main flue unit, wherein the main flue unit comprises an air preheater, a heat exchanger, a dust remover and a wet desulphurization tower which are sequentially connected through a main flue; further comprising: the inlet of the bypass flue unit is communicated with the main flue at the upstream of the air preheater, the outlet of the bypass flue unit is communicated with the main flue between the heat exchanger and the dust remover, and an atomizing nozzle is arranged in the bypass flue unit; the water path unit comprises a first communicating pipeline and a second communicating pipeline, the heat exchanger is provided with a heat exchange pipe, the first communicating pipeline is communicated with the wet desulphurization tower and the heat exchange pipe for leading desulfurization wastewater into the heat exchanger, and the second communicating pipeline is communicated with the heat exchange pipe and the atomizing nozzle.

Different from the conventional design, the desulfurization wastewater in the embodiment of the invention is not directly introduced into the atomizing nozzle, but is heated by the heat exchanger. Like this, can reduce desulfurization waste water's viscosity for desulfurization waste water is by broken atomizing more easily, and, can also reduce the heat demand of bypass flue unit evaporation atomizing back waste water, and double-phase effect can promote the evaporation rate of droplet granule, and then can reduce effectively that the evaporation of droplet granule is incomplete, the droplet granule bumps risks such as wall scale deposit, is favorable to the normal operating of security equipment. Simultaneously, above-mentioned scheme also can utilize the heat of flue gas more fully to can carry out effective control to the temperature of the flue gas that gets into in the dust remover. In addition, the design that the waterway unit flows through the heat exchanger in the embodiment of the invention utilizes the original equipment space, and compared with the conventional design, the design can reduce the occupied space of the waterway unit, thereby reducing the occupied area of the flue gas treatment system provided by the invention.

In addition, after the scheme of the embodiment of the invention is adopted, the heat exchanger is added in the main flue unit and the bypass flue unit which are connected in parallel, the resistance is larger, accordingly, more flue gas can flow into the bypass flue unit, the heat supply in the bypass flue unit can be increased, the evaporation rate of fog drop particles can be improved, the complete evaporation of the fog drop particles can be ensured to a greater extent, and the risks of wall-touching scaling and the like are reduced.

Optionally, the main flue unit comprises a first section and a second section which are arranged at an included angle, the first section is provided with the air preheater, the second section is provided with a connecting end part connected with the first section, and the heat exchanger is positioned at the connecting end part; the heat exchanger has a housing with a flow area that tapers from upstream to downstream.

Optionally, the housing has a top wall, an inner wall surface of the top wall is a first inclined wall surface, and an included angle between the first inclined wall surface and the extending direction of the second segment is less than 30 degrees.

Alternatively, the number of the heat exchange tubes is gradually reduced in the upstream to downstream direction.

Optionally, the lower extreme of first section is configured with first ash bucket, first ash bucket is configured with first ash conveying pipeline, the heat exchanger is configured with the second ash bucket, the second ash bucket is configured with the second ash conveying pipeline, first ash conveying pipeline with the second ash conveying pipeline is linked together.

Optionally, the bypass flue unit includes an evaporation section, the evaporation section extends along a vertical direction, the evaporation section is provided with the atomizing nozzle and a guide grid, the guide grid is located upstream of the atomizing nozzle, the guide grid has a plurality of guide channels, and each guide channel extends along the vertical direction.

Optionally, a flow equalizing pore plate is further arranged in the evaporation section, and the flow equalizing pore plate is located at the upstream of the guide grid.

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

Optionally, the bypass flue unit still includes the export section, the export section has the connection section portion and the discharge section portion that are the contained angle setting, the connection section portion with the bottom portion of evaporation section links to each other, the part of connection section portion with the discharge section portion is located the heat exchanger and between the dust remover the main flue, the flue gas flow direction in the discharge section portion with the heat exchanger and between the dust remover flue gas flow direction in the main flue is unanimous.

Optionally, the waterway unit further comprises a flushing liquid pipe, and the flushing liquid pipe is communicated with the second communication pipeline.

Drawings

FIG. 1 is a schematic diagram of one embodiment of a flue gas treatment system of the prior art;

FIG. 2 is a schematic structural diagram of one embodiment of a flue gas treatment system provided by the present invention;

FIG. 3 is a schematic view of the first and second sections of FIG. 2;

FIG. 4 is a schematic structural diagram of a bypass flue unit, a second communicating pipeline and a third flue section;

fig. 5 is a schematic view of the structure of the guide grid.

The reference numerals in fig. 1 are explained as follows:

01 main flue, 02 air preheater, 03 heat exchanger, 04 electric dust remover, 05 wet desulphurization tower, 06 bypass flue, 07 and treatment device.

The reference numerals in fig. 2-5 are illustrated as follows:

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

112 second flue segment, 112a first ash hopper, 112b first ash conveying pipeline, 113 third flue segment,

114, a fourth flue section, 115, a fifth flue section, 12 air pre-heaters, 13 heat exchangers, 131 first inclined wall surfaces, 132 second ash hoppers, 133 second ash conveying pipelines, 14 dust collectors, 15 wet desulphurization towers and 16 first fans;

2, a bypass flue unit, 21 an evaporation section, 211 atomizing nozzles, 212 guide grids, 212a guide channels, 213 flow equalizing pore plates, 214 a second inclined wall surface, 22 an inlet section, 23 an outlet section, 231 connecting sections, 232 discharging sections and 24 second fans;

3 water channel units, 31 first communication pipelines, 32 second communication pipelines, 33 flushing liquid pipelines, 34 compressed air pipelines, 35 pretreatment devices and 36 water pumps.

Detailed Description

In order to make the technical solutions of the present invention better understood, the present invention is further described in detail with reference to the accompanying drawings and specific embodiments.

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

In the description of the embodiments of the present invention, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly unless otherwise explicitly specified or limited, and for example, "connected" may or may not be detachably connected; may be directly connected or indirectly connected through an intermediate.

Directional phrases used in embodiments of the present invention, such as "vertical," "horizontal," "upper," "lower," "top," "bottom," "inner," "outer," and the like, refer only to the orientation of the figures and, thus, are used in order to better and more clearly illustrate and understand embodiments of the present invention, rather than to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and, thus, should not be taken as limiting the embodiments of the present invention.

In addition, the term "a plurality" as used herein means two or more unless otherwise specified in the present application. And the use of "a number" to indicate a number of elements does not indicate a quantitative relationship between such elements.

In the description of the embodiments of the present invention, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a component of' 8230; \8230;" does not exclude the presence of another like element in a process, method, article, or apparatus that comprises the element.

Referring to fig. 2-5, fig. 2 is a schematic structural diagram of an embodiment of a flue gas treatment system provided by the present invention, fig. 3 is a schematic structural diagram of a first segment and a second segment in fig. 2, fig. 4 is a schematic structural diagram of a bypass flue unit, a second communicating pipe and a third flue segment, and fig. 5 is a schematic structural diagram of a guide grid.

As shown in fig. 2, the present invention provides a flue gas treatment system for treating sulfur-containing flue gas in the form of coal-fired flue gas, metallurgical flue gas, etc., comprising a main flue unit 1, a bypass flue unit 2, and a waterway unit 3.

The main flue unit 1 includes an air preheater 12, a heat exchanger 13, a dust collector 14, and a wet desulfurization tower 15, which are connected in this order through a main flue 11. The air preheater 12 is used for preheating air, so that the flue gas waste heat can be fully utilized; the heat exchanger 13 is used for carrying out temperature control and heat exchange on the flue gas so as to control the temperature of the flue gas entering the dust remover 14, and meanwhile, the recovery of the flue gas waste heat can also be realized; the dust collector 14 may be a dust collecting component in the form of an electric dust collector, a bag-type dust collector, a cyclone dust collector, or the like, and is configured to capture and collect dust in the flue gas; the wet desulfurization tower 15 is used for desulfurization treatment of the flue gas, and the wet desulfurization tower 15 generates desulfurization wastewater.

In the flowing process of the flue gas in the main flue unit 1, the power of the flue gas 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 the requirement of use can be met. In the embodiment of fig. 2, the first fan 16 may be disposed on the main flue 11 between the dust separator 14 and the wet desulfurization tower 15.

For convenience of description, embodiments of the present invention may name the flues 11 at various locations separately. Specifically, the main flue 11 upstream of the air preheater 12 may be referred to as a first flue section 111, the main flue 11 between the air preheater 12 and the heat exchanger 13 may be referred to as a second flue section 112, the main flue 11 between the heat exchanger 13 and the dust remover 14 may be referred to as a third flue section 113, the main flue 11 between the dust remover 14 and the first fan 16 may be referred to as a fourth flue section 114, and the main flue 11 between the first fan 16 and the wet desulfurization tower 15 may be referred to as a fifth flue section 115.

The inlet of the bypass flue unit 2 is communicated with the main flue 11 upstream of the air preheater 12, and the outlet of the bypass flue unit 2 is communicated with the main flue 11 between the heat exchanger 13 and the dust remover 14, that is, the bypass flue unit 2 may be communicated with the first flue section 111 and the third flue section 113 for extracting high-temperature flue gas in the first flue section 111. An atomizing nozzle 211 is provided in the bypass flue unit 2.

The waterway unit 3 includes a first communicating pipe 31 and a second communicating pipe 32. The first communicating pipe 31 is directly connected to the wet desulfurization tower 15, and is used for leading out desulfurization wastewater generated by the wet desulfurization tower 15. The first communicating pipe 31 is further provided with a pretreatment device 35 for pretreating desulfurization wastewater to obtain a byproduct gypsum; the specific structural form of the pretreatment device 35 is not limited herein, and may be determined by referring to the related art as long as it can satisfy the actual use requirement. The first communication pipe 31 may be further provided with a water pump 36 for powering the operation of the waterway unit 3; it should be understood that the water pump 36 may be disposed at other positions of the water path unit 3, as long as the operation requirement of the water path unit 3 can be met, and for example, the water pump 36 may also be disposed at the second communication pipe 32.

The heat exchanger 13 has a heat exchange pipe (not shown in the figure) to which the first communicating pipe 31 is also communicated for introducing the desulfurization waste water into the heat exchange pipe to exchange heat with the flue gas in the heat exchanger 13, so that the desulfurization waste water can be subjected to temperature raising treatment. The second communicating pipe 32 can communicate the heat exchange pipe and the atomizing nozzle 211, can guide the desulfurization wastewater after the temperature rise into the atomizing nozzle 211, and the atomizing nozzle 211 can atomize the desulfurization wastewater into mist particles and spray the mist particles into the bypass flue unit 2, and the mist particles can be evaporated under the action of high-temperature flue gas in the bypass flue unit 2, so as to realize the evaporation treatment of the desulfurization wastewater generated by the wet desulfurization tower 15.

In contrast to the conventional design (the scheme in fig. 1), the desulfurization waste water in the embodiment of the present invention is not directly introduced into the atomizing nozzle 211, but is first heated by the heat exchanger 13. Like this, can reduce desulfurization waste water's viscosity for desulfurization waste water is more easily by broken atomizing, and, can also reduce the heat demand of evaporating atomizing back waste water in the bypass flue unit 2, and double-phase effect can promote the evaporation rate of droplet granule, and then can reduce droplet granule evaporation incomplete effectively, the droplet granule bumps risks such as wall scale deposit, is favorable to the normal operating of guarantee equipment. Meanwhile, 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 remover 14. In addition, the design that the waterway unit 3 flows through the heat exchanger 13 in the embodiment of the invention utilizes the original equipment space, and compared with the conventional design, the occupied space of the waterway unit 3 can be reduced, so that the occupied area of the flue gas treatment system provided by the invention can be further reduced.

In addition, as can be seen by comparing fig. 1 and fig. 2, after the scheme of the embodiment of the present invention is adopted, the heat exchanger 13 is added to the portion of the main flue unit 1 connected in parallel with the bypass flue unit 2, the resistance is relatively large, accordingly, more flue gas can flow into the bypass flue unit 2, the heat supply in the bypass flue unit 2 can be increased, the evaporation rate of the mist droplet particles can be increased, the complete evaporation of the mist droplet particles can be ensured to a greater extent, and the risks of fouling and the like due to wall collision can be further reduced.

From another perspective, the bypass flue unit 2 may actually cause heat overflow because the heat requirement for evaporating the atomized wastewater in the bypass flue unit 2 is reduced, and the bypass flue unit 2 can introduce more heat. Therefore, when the system is designed, the volume of the bypass flue unit 2 is less, which can further reduce the floor area of the flue gas treatment system provided by the invention, and further reduce the cost of the equipment.

Here, the embodiment of the present invention does not limit the specific structural form, number and the like of the atomizing nozzles 211, and in practical applications, a person skilled in the art may set the atomizing nozzles according to specific needs as long as the requirements of use can be met. For example, the atomizing nozzle 211 may be a two-fluid nozzle, in this case, the water path unit 3 may further include a compressed air pipe 34, in addition to the second communication pipe 32, for introducing compressed air into the atomizing nozzle 211 to break up the wastewater particles and form an atomization; in addition, the atomizing nozzle 211 may be a pressure atomizing nozzle, a rotary atomizing nozzle, a bubble atomizing nozzle, or the like.

In some alternative embodiments, as shown in fig. 3, 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 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 a corner junction of the first section 1a and the second section 1b; the heat exchanger 13 may have a housing, the flow area of which may be tapered from upstream to downstream. The extending directions of the first section 1a and the second section 1b are not limited herein, and in practical application, a person skilled in the art can design according to specific needs as long as the person can meet practical use requirements; in the embodiment shown in fig. 3, the first segment 1a may extend in a vertical direction, and the second segment 1b may extend in a horizontal direction, in which case the first segment 1a and the second segment 1b may form an included angle of 90 degrees.

By adopting the scheme, the corner positions of the first section 1a and the second section 1b and the arrangement position of the heat exchanger 13 are integrated in the same region, the resistance at the corner positions and the resistance of the heat exchanger 13 can be combined in the same region, then the turning angles 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, the resistance level in the main flue unit 1 can be greatly reduced, and the technical effects of resistance reduction and energy saving are achieved; and, through the convergent design of heat exchanger 13 casing, can be with the velocity of flow control of flue gas in heat exchanger 13 at the velocity of flow window of preferred, this not only can promote heat exchange efficiency of heat exchanger 13, simultaneously, can also reduce the deposition problem in the heat exchanger 13 to a great extent.

Furthermore, in the embodiment of the invention, a flared section of the housing of the heat exchanger 13 is omitted, as compared with the conventional design (solution in fig. 1), and the design of the heat exchanger 13 can also be relatively simple.

The cross-sectional shape of the casing of the heat exchanger 13 may be rectangular, and in combination with fig. 3, the casing may have a top wall, an inner wall surface of the top wall may be a first inclined wall surface 131, and an extending direction of the first inclined wall surface 131 and the second section 1b may be set at an included angle, so as to form the aforesaid tapered design, and the top wall may further guide the flue gas in the first section 1a, so as to smooth a turning angle between the first section 1a and the second section 1b, and further reduce the flow resistance of the flue gas. It should be understood that, in the case that the top wall of the casing of the heat exchanger 13 is of an equal thickness, the whole top wall may be arranged at an angle to the extending direction of the second section 1b; on the other hand, if the top wall is an unequal thick plate, only the configuration of the inner wall surface of the top wall may be limited.

The size of the included angle between the first inclined wall surface 131 and the extending direction of the second section 1b is not limited herein, and in practical applications, a person skilled in the art may design the included angle according to specific needs as long as the included angle can meet the requirements of use. For example, the included angle may be set to be smaller than 30 °, and at this time, the change of the flow area of the shell is relatively smooth, which is more beneficial to reducing the flow resistance, so as to achieve the technical effects of reducing drag and saving energy.

It should be understood that the tapered housing constructed by the first inclined wall 131 is only an exemplary illustration of the embodiment of the present invention, and is not intended to limit the scope of the flue gas treatment system provided by the present invention, and other configurations can be adopted if they are satisfactory. For example, the cross section of the shell may be circular, in which case, the shell may be a circular table structure; alternatively, the first inclined wall 131 may be provided not on the top wall of the housing but on another wall of the housing, as long as the finally formed housing exhibits a tapered design in its flow area; in addition, the first inclined wall surface 131 is not limited to a plane, and may be a curved surface, such as an arc surface.

In some alternative embodiments, the number of heat exchange tubes may gradually decrease in the upstream to downstream direction within the housing of the heat exchanger 13.

It should be understood that the flue gas flow area = shell flow area-heat exchange tube blocking area in the heat exchanger 13, and that the greater the number of heat exchange tubes, the greater the blocking area of the heat exchange tubes. As mentioned earlier, from the upper reaches to the low reaches, the flow area of casing can dwindle gradually, on this basis, reduces the quantity of heat exchange tube, can guarantee to a certain extent in the heat exchanger 13 the uniformity of flue gas flow area, can stabilize the inside flue gas velocity of flow in heat exchanger 13 at the velocity of flow window of aforesaid preferred to do benefit to and improve heat exchange efficiency and reduce the deposition problem.

Here, the decreasing amplitude of the number of the heat exchange tubes is not limited in the embodiment of the present invention, and in practical applications, a person skilled in the art may determine the decreasing amplitude in combination with specific use requirements as long as the corresponding technical effect can be achieved. Illustratively, from upstream to downstream, a plurality of heat exchange tube sets may be arranged in the heat exchanger 13, and the number of heat exchange tubes in the downstream heat exchange tube set may be reduced by 1 to 3 compared with the number of heat exchange tubes in the adjacent heat exchange tube set.

In some alternative 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 pipe 112b for discharging the dust in the first section 1 a; the heat exchanger 13 may be configured with a second ash hopper 132, and the second ash hopper 132 may be configured with a second ash conveying pipeline 133 for discharging the dust in the heat exchanger 13, so as to effectively avoid or reduce the problem of ash deposition in the heat exchanger 13.

Further, the first ash conveying pipeline 112b and the second ash conveying pipeline 133 may be communicated to improve the integration of the pipelines, facilitate the centralized processing of the dust, and reduce the cost of adding the ash conveying pipeline.

With reference to fig. 4, the bypass flue unit 2 may include an evaporation section 21, the evaporation section 21 may extend in a vertical direction, the atomizing nozzle 211 may be disposed in the evaporation section 21, and the evaporation process of the mist particles substantially occurs in the evaporation section 21.

The evaporation section 21 may also be provided with a guide grate 212, which guide grate 212 may be located upstream of the atomizing nozzle 211 for guiding the flue gas flowing towards the atomizing nozzle 211. Specifically, the guide grid 212 may have a plurality of guide channels 212a, and each guide channel 212a extends in the vertical direction, so that the flue gas substantially flows in the vertical direction, thereby creating a good flow field condition for evaporation of the mist droplet particles, and preventing the mist droplet particles from colliding against the inner wall of the evaporation section 21 in the process of spraying, thereby reducing the risk of fouling due to collision against the wall.

The structural form of the grating plate 212 may be adjusted as required, and is not limited herein as long as it can meet the use requirement. Illustratively, as shown in fig. 5, the ratio of the height H and the pitch L of the guide channels 212a (i.e., the grid apertures) of the grid plate 212 may be in the following range: H/L <3, and is used for improving the verticality of the airflow.

In some optional embodiments, a flow equalizing pore plate 213 may be further disposed in the evaporation section 21, and the flow equalizing pore plate 213 may be located upstream of the guide grid 212 for improving the uniformity of the flow of the flue gas in the evaporation section 21.

Similarly, the structural form of the equalizing pore plate 213 can be adjusted as required as long as it can meet the use requirement. For example, the flow equalizing pore plate 213 may be a steel plate with circular holes, and the diameter of the circular holes may be no greater than 50mm; of course, the shape of the holes formed in the flow equalizing hole plate 213 is not limited to circular holes, and rectangular holes, triangular holes, or other types of holes may be used.

As shown in fig. 4, the bypass flue unit 2 may further include an entrance section 22, the entrance section 22 may be connected to a top end portion of the evaporation section 21, an inner wall surface of a top wall of the evaporation section 21 may be a second inclined wall surface 214, and the second inclined wall surface 214 may be gradually inclined downward along a direction away from the entrance section 22 to smooth a turning angle between the entrance section 22 and the evaporation section 21, so as to reduce a flow resistance of the flue gas, and achieve a technical effect of reducing drag and saving energy. It will be understood that in the case where the top wall of the evaporation section 21 is of an equal thickness, the top wall as a whole may appear to be gradually downwardly inclined; on the other hand, if the top wall is an unequal thick plate, only the configuration of the inner wall surface of the top wall may be limited.

The second inclined wall surface 214 may be a plane or a curved surface, and in the case of the curved surface, the second inclined wall surface 214 may be an arc-shaped surface, similar to the first inclined wall surface 131. The angle of inclination of the second inclined wall surface 214 is also not limited herein.

It should be understood that the above description of the connection between the inlet section 22 and the evaporation section 21 via the second inclined wall 214 is only an exemplary illustration of the embodiment of the present invention, and is not intended to limit the scope of the implementation of the flue gas treatment system provided by the present invention, and that the connection between the inlet section 22 and the evaporation section 21 may be implemented in other configurations if the functions are satisfied. Illustratively, the inlet section 22 and the evaporation section 21 may be connected by an elbow pipe + divergent pipe structure, as shown in fig. 1.

In some optional embodiments, the bypass flue unit 2 may further include an outlet section 23, the outlet section 23 may have a connection section 231 and a discharge section 232 arranged at an included angle, and the connection section 231 is connected to the bottom end of the evaporation section 21, specifically, may be in transition connection through a reducer; the portion of the connection section 231 and the exhaust section 232 may be located within the third flue segment 113, and the flue gas flow direction within the exhaust section 232 may coincide with the flue gas flow direction within the third flue segment 113. By adopting the scheme, the flue gas in the bypass flue unit 2 can be prevented from disturbing the distribution state of the flow field in the third flue section 113 to a greater extent, and further the influence on the dust removal efficiency of the dust remover 14 due to the change of the flow field can be avoided.

Similar to the operation of the main flue unit 1, the operation of the bypass flue unit 2 may also be performed by means of a fan, and for the sake of convenience, the fan disposed in the bypass flue unit 2 may be referred to as a second fan 24, and the second fan 24 may be disposed at any position of the bypass flue unit 2 as long as the function thereof can be achieved. In the embodiment of fig. 2, the second fan 24 may be disposed at the inlet section 22.

In some optional embodiments, the waterway unit 3 may further include a rinsing liquid pipe 33, and the rinsing liquid pipe 33 may be communicated with the second communication pipe 32 to introduce a rinsing liquid into the atomizing nozzle 211, and the rinsing liquid may clean the atomizing nozzle 211, so as to reduce the risk of the atomizing nozzle 211 being blocked.

The composition of the washing liquid can be selected according to the composition of the desulfurization wastewater, and generally, the washing liquid can be acid liquid or alkali liquid. The valve of the flushing-liquid duct 33 can be in a closed state during normal operation of the system, and when a certain operating condition occurs, the valve of the flushing-liquid duct 33 can be opened in order to introduce the flushing liquid into the atomizing nozzle 211 in a timely manner.

The situation of the specific working condition is not limited herein, and may be determined by combining the actual device operation condition. The following are exemplary: 1) When the bypass flue unit 2 is switched from off to on, namely, each time the device is started, the atomizing nozzle 211 can be flushed by flushing liquid; 2) When the monitoring variable is abnormal and the atomizing nozzle 211 is judged to be possibly blocked, under the working condition, the valve of the desulfurization wastewater can be closed firstly to block the introduction of the desulfurization wastewater, and then the valve of the flushing fluid pipeline 33 is opened; the monitored variable may be a parameter such as differential pressure, flow rate, etc.

In summary, the flue gas treatment system provided by the embodiment of the invention adopts a series of complementary and mutually-promoted measures, so that the risks of blockage of the atomizing nozzle 211, collision of fog drops on the wall and scaling of the flue can be greatly reduced, the problems of dust accumulation of the heat exchanger 13, insufficient extraction amount of bypass flue gas and the like can be greatly solved, meanwhile, the system occupies a smaller area, is more stable in operation, and makes great technical progress compared with the prior art.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.

Claims (10)

1. The utility model provides a flue gas processing system, includes main flue unit (1), main flue unit (1) includes air preheater (12), heat exchanger (13), dust remover (14) and wet flue gas desulfurization tower (15) that connect gradually through main flue (11), its characterized in that still includes:

the inlet of the bypass flue unit (2) is communicated with the main flue (11) at the upstream of the air preheater (12), the outlet of the bypass flue unit (2) is communicated with the main flue (11) between the heat exchanger (13) and the dust remover (14), and an atomizing nozzle (211) is arranged in the bypass flue unit (2);

waterway unit (3), including first communicating pipe (31) and second communicating pipe (32), heat exchanger (13) have the heat exchange tube, first communicating pipe (31) intercommunication wet flue gas desulfurization tower (15) with the heat exchange tube for with desulfurization waste water leading-in heat exchanger (13), second communicating pipe (32) intercommunication the heat exchange tube with atomizing nozzle (211).

2. The flue gas treatment system according to claim 1, wherein the main flue unit (1) comprises a first section (1 a) and a second section (1 b) arranged at an angle, the first section (1 a) being provided with the air preheater (12), the second section (1 b) having a connection end to the first section (1 a), the heat exchanger (13) being located at the connection end;

the heat exchanger (13) has a housing, the flow area of which is arranged tapering from upstream to downstream.

3. The flue gas treatment system according to claim 2, wherein the housing has a top wall, an inner wall surface of the top wall being a first inclined wall surface (131), an angle between the first inclined wall surface (131) and an extension direction of the second section (1 b) being smaller than 30 degrees.

4. The flue gas treatment system of claim 2, wherein the number of heat exchange tubes decreases in an upstream to downstream direction.

5. The flue gas treatment system according to claim 2, wherein the lower end of the first section (1 a) is provided with a first ash hopper (112 a), the first ash hopper (112 a) is provided with a first ash conveying pipeline (112 b), 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 (112 b) and the second ash conveying pipeline (133) are communicated.

6. The flue gas treatment system according to any one of claims 1-5, wherein 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 grate (212), the guide grate (212) being located upstream of the atomizing nozzle (211), the guide grate (212) having a number of guide channels (212 a), each guide channel (212 a) extending in a vertical direction.

7. The flue gas treatment system according to claim 6, wherein a flow equalizing aperture plate (213) is further disposed in the evaporation section (21), and the flow equalizing aperture plate (213) is located upstream of the guide grid (212).

8. The flue gas treatment system of claim 6, wherein the bypass flue unit (2) further comprises an inlet section (22), the inlet section (22) being connected to a top end portion of the evaporation section (21), an inner wall surface of a top wall of the evaporation section (21) being a second inclined wall surface (214), the second inclined wall surface (214) being gradually inclined downwards in a direction away from the inlet section (22).

9. The flue gas treatment system according to claim 6, wherein the bypass flue unit (2) further comprises an outlet section (23), the outlet section (23) has a connection section (231) and a discharge section (232) arranged at an included angle, the connection section (231) is connected with the bottom end of the evaporation section (21), the connection section (231) and the discharge section (232) are located in the main flue (11) between the heat exchanger (13) and the dust remover (14), and the flow direction of the flue gas in the discharge section (232) is consistent with the flow direction of the flue gas in the main flue (11) between the heat exchanger (13) and the dust remover (14).

10. The flue gas treatment system according to any of claims 1 to 5, wherein the water circuit unit (3) further comprises a flushing liquid pipe (33), the flushing liquid pipe (33) being in communication with the second communication duct (32).

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