Flue gas desulfurization and fog dispersal device
Technical Field
The invention relates to the technical field of chemical engineering and environmental protection, in particular to a flue gas desulfurization and fog dissipation device.
Background
Petrochemical industry,Flue gas in industries such as electric power contains a large amount of sulfur dioxide, and the flue gas is directly discharged to pollute air and form environmental disasters such as acid rain. At present, the industrial application is provided with a desulphurization device for removing sulfur dioxide in flue gas. For example, the spray absorption tower adopts a circulating pump to spray desulfurization slurry out through a nozzle, the atomized slurry is contacted with the flue gas in a spray area, and SO in the flue gas is absorbed2And the gas falls into a bottom liquid pool at the bottom of the absorption tower. The desulfurized flue gas flows upwards to be discharged out of the tower, and the desulfurized flue gas is mixed with cold air after being discharged out of a chimney due to high temperature and high humidity, so that water vapor in the flue gas is suddenly condensed to form white smoke, visual pollution is easily caused, and the environment is influenced to be attractive. In order to reduce the visibility of the flue gas and eliminate white smoke formed above a discharge chimney, the prior art generally adopts a flue gas reheating method, or a flue gas-flue gas heat exchanger (GGH) is used, namely the heat of high-temperature flue gas before desulfurization is used for heating the desulfurized flue gas to enable the temperature of the desulfurized flue gas to be higher than 75-80 ℃; or a steam-flue gas heat exchanger (SGH) is used, namely boiler steam is used for heating desulfurized flue gas, so that the temperature of the desulfurized flue gas is higher than 80-90 ℃. The former has very expensive investment and operation cost, and can encounter the problems of acid dew point corrosion of equipment and blockage and leakage of the equipment, and the early use is more; the latter involves the problem of extra energy consumption.
Therefore, a flue gas desulfurization and fog dispersal device with more efficient and reasonable heat utilization is needed, so that energy is saved and cost is reduced.
The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
Disclosure of Invention
The invention aims to provide a flue gas desulfurization and fog dispersal device, thereby reducing the problem of energy loss in the prior art.
Another object of the present invention is to provide a flue gas desulfurization and fog dispersal device, thereby effectively recovering condensed water while dispersing fog.
In order to achieve one or more of the above objects, the present invention provides a flue gas desulfurization and defogging device, including: the device comprises a spray absorption tower, a fog dissipation cooling tower, a heat exchanger and a draught fan. The spray absorption tower comprises: the raw flue gas inlet is arranged at the lower part of the spray absorption tower; a first sprayer capable of spraying the desulfurization slurry to the raw flue gas; a bottom liquid pool which can receive and store the desulfurization slurry sprayed by the first sprayer; and the circulating pump is used for pumping the desulfurization slurry in the bottom liquid pool and conveying the desulfurization slurry to the first sprayer. Fog dispersal cooling tower, it sets up the top at fountain absorption tower, and this fog dispersal cooling tower includes: the fog dispersal filler is provided with a cold air inlet on one side and a gas collection chamber on the other side; a second sprayer capable of spraying cooling water to the defogging filler; and the purified flue gas outlet is arranged at the top end of the fog dissipation cooling tower. The heat exchanger is arranged in the bottom liquid pool, one end of the heat exchanger is communicated with the gas collection chamber, and the other end of the heat exchanger is communicated with the purified flue gas outlet. The induced draft fan is arranged on a pipeline between the gas collection chamber and the heat exchanger. Under the action of the draught fan, cold air enters the air collection chamber through the fog dispersal filler, is pressed into the heat exchanger and is discharged through the smoke purification outlet.
Further, among the above-mentioned technical scheme, flue gas desulfurization fog dispersal device still includes the blender, and it sets up in the top of second spray thrower, and this blender can mix the clean flue gas that comes from the air of heat exchanger and comes from the defogging filler.
Further, in the above technical scheme, the mixer is a venturi mixer.
Further, in the above technical solution, the mixer includes: the main pipeline is communicated with the other end of the heat exchanger; a hot air nozzle provided on the main pipeline; and a venturi ejector disposed on the hot air nozzle. The air from the heat exchanger enters the main pipeline, enters the Venturi ejector through the hot air nozzle, is mixed with the clean smoke from the fog dispersal filler, and is discharged through the clean smoke outlet.
Further, in the above technical scheme, a baffle is arranged between the heat exchanger and the mixer.
Further, in the above technical scheme, the heat exchanger is a heat-taking coil.
Furthermore, in the above technical scheme, the fog dispersal filler is composed of heat exchange fins, the heat exchange fins form a cold channel and a hot channel which are arranged in a cross way and are not communicated with each other, one end of the cold channel is connected with a cold air inlet, the other end of the cold channel is communicated with a gas collection chamber, the lower end of the hot channel is communicated with a spray type absorption tower, the upper end of the hot channel is communicated with a clean flue gas outlet, a second sprayer sprays cooling water to the hot channel, and the cooling water forms a liquid film on the surface of the hot channel and flows downwards.
Further, in the above technical scheme, the heat exchange plate is made of plastic or metal.
Further, in the above technical scheme, the induced draft fan is a centrifugal fan or a roots type fan.
Further, in the above technical scheme, the fog dispersal cooling tower further comprises a distribution chamber, and the raw flue gas is desulfurized by the spray absorption tower and then is uniformly distributed into the fog dispersal filler by the distribution chamber.
Further, in the above technical solution, the spray absorption tower further includes: and the gas-liquid separator is arranged above the first sprayer.
Further, in the above technical solution, the first sprayer is multi-layered.
Further, in the above technical solution, the second sprayer is branch-shaped or ring-shaped.
Further, among the above-mentioned technical scheme, flue gas desulfurization fog dispersal device still includes: and the cooler is used for providing cooling water for the second sprayer.
Further, in the above technical scheme, the cooler is a trickle filler cooling tower, a mechanical refrigerator or an absorption refrigerator.
Compared with the prior art, the invention has the following beneficial effects:
1. the heat of the desulfurization slurry in the bottom liquid pool of the spray absorption tower is utilized to heat air after the defogging filler is hot, the air temperature is further improved, the temperature of the desulfurization slurry is reduced, and the heat in the system is effectively utilized.
2. The fog dissipation filler adopts the heat exchange sheets and the liquid film to conduct heat at intervals, eliminates the influence of dust deposition in the flue gas, and can efficiently absorb the condensed water in the flue gas.
3. Set up the blender and can discharge behind hot back air and the clean flue gas intensive mixing, simultaneously, the blender of venturi form can make full use of hot air pressure head, forms the negative pressure zone in hot air spout surrounding space, effectively produces the suction effect to clean flue gas, can reduce the whole tower pressure drop of fountain absorption tower by a wide margin, reduces the demand to flue gas pressure head, energy saving and consumption reduction.
4. The first sprayer is arranged into a plurality of layers, so that the desulfurization slurry is sprayed more uniformly, and the desulfurization effect is better.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood and to make the technical means implementable in accordance with the contents of the description, and to make the above and other objects, technical features, and advantages of the present invention more comprehensible, one or more preferred embodiments are described below in detail with reference to the accompanying drawings.
Drawings
Fig. 1 is a schematic structural diagram of a flue gas desulfurization and defogging device according to an embodiment of the invention.
Fig. 2 is a schematic structural view of a defogging filler according to an embodiment of the present invention.
FIG. 3 is a schematic cross-sectional view of a defogging filler according to an embodiment of the present invention.
Fig. 4 is a schematic structural view of a mixer according to an embodiment of the present invention.
Description of the main reference numerals:
1-a spray type absorption tower, 11-a raw flue gas inlet, 12-a circulating pump, 13-a first sprayer, 131-a first nozzle, 14-a bottom liquid pool, 15-a gas-liquid separator, 2-a fog-removing cooling tower, 21-a distribution chamber, 22-fog-removing filler, 221-a heat exchange sheet, 222-a cold channel, 223-a hot channel, 223 a-a liquid film, 23-a second sprayer, 231-a second nozzle, 232-a cooler, 24-a mixer, 241-a main pipeline, 241a hot air nozzle, 242-a venturi ejector, 25-a clean flue gas outlet, 31-a gas collection chamber, 32-an induced draft fan, 33-a heat exchanger and 34-a baffle.
Detailed Description
The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.
Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.
Spatially relative terms, such as "below," "lower," "upper," "above," "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the object in use or operation in addition to the orientation depicted in the figures. For example, if the items in the figures are turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the elements or features. Thus, the exemplary term "below" can encompass both an orientation of below and above. The article may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative terms used herein should be interpreted accordingly.
In this document, the terms "first", "second", etc. are used to distinguish two different elements or portions, and are not used to define a particular position or relative relationship. In other words, the terms "first," "second," and the like may also be interchanged with one another in some embodiments.
As shown in fig. 1, the flue gas desulfurization and defogging device according to the embodiment of the invention comprises a spray type absorption tower 1 for original flue gas desulfurization, and a defogging cooling tower 2 is arranged at the top end of the spray type absorption tower. The lower part of the spray absorption tower 1 is provided with a raw flue gas inlet 11, and raw flue gas (flue gas to be desulfurized) can enter the spray absorption tower 1 through the raw flue gas inlet 11. The desulfurization slurry is sent to the first sprayer 13 in the upper middle portion of the spray absorber 1 by the circulation pump 12, and is sprayed out through the first nozzle 131. Illustratively, the first sprayer 13 is provided with a plurality of layers, and a plurality of first nozzles 131 are distributed on each layer. Illustratively, as shown in FIG. 1, the first injectionThe shower 13 has three layers. The atomized desulfurization slurry is contacted with the raw flue gas, and SO in the raw flue gas2Etc. are absorbed. The flue gas after spraying, cooling, desulfurizing and dedusting carries the desulfurized slurry upward to enter a gas-liquid separator 15 to remove the desulfurized slurry. Absorption of SO2The desulfurized slurry falls into a bottom liquid pool 14 at the bottom of the spray type absorption tower 1, and then is conveyed to a first sprayer 13 by a circulating pump 12 to continuously spray and absorb SO in the original flue gas2And forming the circulation of the desulfurization slurry. It should be noted that fresh desulfurization slurry is continuously added during the process, and part of the desulfurization slurry is discharged for gypsum preparation, which belongs to the prior art and is not described herein.
Further, referring to fig. 1, in one or more exemplary embodiments of the present invention, the clean flue gas (desulfurized flue gas) enters the defogging cooling tower 2 from the top end of the spray absorption tower 1. The fog dispersal cooling tower 2 is respectively provided with a distribution chamber 21, a fog dispersal filler 22, a second sprayer 23 and a clean flue gas outlet 24 from bottom to top. The spray water is cooled by the cooler 232, then is fed into the second sprayer 23, and is sprayed on the defogging filler 22 through the second nozzle 231. The purified flue gas uniformly enters the fog dispersal filler 22 upwards through the distribution chamber 21, and is discharged through the purified flue gas outlet 24 after being subjected to heat exchange and temperature reduction with spray water. The second sprayer 23 is exemplarily branched or annular, and the present invention is not limited thereto. Illustratively, the cooler 232 may be a trickle-fill cooling tower, a mechanical refrigerator, or an absorption refrigerator, but the invention is not limited thereto.
Further, referring to fig. 1, in one or more exemplary embodiments of the present invention, a cool air inlet (not shown) is provided at one side of the fog dispersal packing 22 of the fog dispersal cooling tower 2, and an air collection chamber 31 is provided at the other side, so that outside cool air can enter through the cool air inlet, and then enter the air collection chamber 31 after passing through the fog dispersal packing 22 to exchange heat with the clean flue gas. The cold air entering the air collection chamber 31 is sucked into a heat exchanger 33 arranged in the bottom liquid pool 14 by an induced draft fan 32, and the cold air exchanges heat with the desulfurization slurry in the bottom liquid pool 14 to heat. A mixer 24 is arranged between the second sprayer 23 and the clean flue gas outlet 25, and the cold air passing through the heat exchanger 33 returns to the fog dissipation cooling tower 2 along a pipeline, is mixed with the clean flue gas through the mixer 24 and is discharged from the clean flue gas outlet 25. Illustratively, the induced draft fan 32 may be a centrifugal fan or a roots-type fan. Illustratively, the heat exchanger 33 may be a heat-extracting coil. Illustratively, a flow regulating baffle 34 is provided between the heat exchanger 33 and the mixer 24.
Referring to fig. 2 and 3, in one or more embodiments of the present invention, the defogging filler 22 is formed by arranging the heat exchange fins 221 to form a cold channel 222 and a hot channel 223 which are arranged in a crossed manner, and the two channels are not communicated with each other. Illustratively, hot aisle 223 and cold aisle 222 extend in mutually perpendicular directions. Illustratively, the heat exchanger fins 221 are made of plastic or metal. The hot channel 223 of the defogging filler 22 receives the spraying of the second sprayer 23, the spraying water forms a liquid film 223a on the surface of the heat exchange plate 221 of the hot channel 223 and flows downwards, and the damp-heat clean smoke flows upwards.
Referring to FIG. 4, in one or more embodiments of the invention, the mixer 24 includes a main pipeline 241, a plurality of hot air jets 241a are provided on the main pipeline 241, and a venturi ejector 242 is provided on each hot air jet 241 a. The air heated by the heat exchanger 33 is sprayed into the venturi ejector 242 through the hot air nozzle 241a, and is first necked down and accelerated, and then decelerated and depressurized to generate suction force, and the surrounding clean flue gas is sucked into the venturi ejector 242 to be uniformly mixed with the air and then discharged from the clean flue gas outlet 25.
In one or more embodiments of the present invention, referring to fig. 1 to 4, at an ambient temperature of about 30 ℃, an ambient humidity of about 65%, and a high-temperature to-be-desulfurized and dust-removed catalytic flue gas (raw flue gas) of about 180 ℃ enters the spray absorption tower 1 from the raw flue gas inlet 11, the first nozzle 131 of the first sprayer 13 sprays desulfurized slurry onto the raw flue gas, the raw flue gas is desulfurized and dust-removed, and the temperature is reduced to about 60 ℃, and the flue gas enters the gas-liquid separator 15 to remove the desulfurized slurry carried in the flue gas. Purified saturated flue gas at about 60 ℃ flows upwards from the spray absorption tower 1 through the distribution chamber 21 of the defogging cooling tower 2 and is uniformly distributed into the hot channel 223 of the defogging filler 22. The spray water is cooled to about 30 ℃ by the cooler 232, and is sprayed onto the hot channel 223 of the defogging filler 22 through the second nozzle 231 of the second sprayer 23, and a liquid film 223a is formed on the surface of the heat exchange sheet 221 in the hot channel 223. The liquid film 223a flows from top to bottom along the surface of the heat exchange plate 221, and is in countercurrent contact with the purified saturated flue gas, the purified saturated flue gas is reduced to about 50 ℃, and the temperature of the liquid film 223a is increased to more than 45 ℃. In the process, the liquid film 223a and the contact surface of the flue gas have mass and heat transfer effects, and saturated water is separated out after the temperature of the flue gas is reduced and is captured and absorbed by the liquid film 223 a. After the temperature of the liquid film 223a rises, the heat is transferred to the cold air in the cold channel 222 through the heat exchange plate 221, and the cold air flowing through the fog dispersal filler 22 is heated to about 40 ℃ under the action of the induced draft fan 32 and enters the air collection chamber 31. The induced draft fan 32 sucks the cold air in the air collection chamber 31 and presses the cold air into a heat exchanger 33 positioned in the bottom liquid pool 14. The desulfurization slurry falls into a bottom liquid pool after absorbing sulfur components and dust in the original flue gas, and the temperature is about 60 ℃. The temperature of the air pressed by the draught fan 32 is further raised to above 45 ℃ through the heat transfer of the heat exchanger 33. After the flow is adjusted by the baffle 34, the air enters the mixer 24, is mixed with the clean flue gas at about 50 ℃ from the defogging filler 22, and is discharged from the clean flue gas outlet 25.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. Any simple modifications, equivalent changes and modifications made to the above exemplary embodiments shall fall within the scope of the present invention.