CN113996155A - Smoke whitening device, chimney and smoke whitening method - Google Patents

Abstract

The invention discloses a smoke whitening device, a chimney and a smoke whitening method. The disclosed smoke whitening device comprises a cylinder body, wherein a smoke channel is formed in the cylinder body, and at least one air introducing channel communicated with the smoke channel and the space outside the cylinder body is formed in the cylinder body so as to introduce air into the smoke channel. By utilizing the smoke whitening device, air is introduced into the smoke channel through the air introduction channel and is mixed with smoke to be treated. Because the air has low water content and is relatively dry, the humidity of the smoke to be treated can be reduced, and then the smoke to be treated can be kept in an unsaturated state, so that the condensation of water can be avoided or reduced, and the aim of eliminating or reducing the white smoke phenomenon of the smoke can be fulfilled. The smoke whitening device provided by the invention can realize smoke whitening by introducing air in advance only based on the air introducing channel on the cylinder, has a simple and reliable structure, and keeps lower cost.

Description

Smoke whitening device, chimney and smoke whitening method

Technical Field

The invention relates to an industrial flue gas treatment technology, in particular to a flue gas whitening device, a chimney comprising the flue gas whitening device and a flue gas whitening method using the flue gas whitening device.

Background

The flue gas discharged from power plant boilers, petrochemical heating furnaces and the like contains pollutants such as sulfur, nitrate and the like. In order to prevent pollution events such as acid rain and the like caused by direct emission of flue gas, the flue gas is generally purified in a proper manner at present, so that pollutants in the flue gas are reduced or removed.

At present, the common purification mode for desulfurization or denitration of flue gas is wet process, even if the flue gas contacts with the slurry containing absorbent, the pollutants in the flue gas are absorbed and separated for harmless treatment, and the purified flue gas is discharged into the atmosphere.

When the flue gas is purified by a wet process, the water content is higher, and when the flue gas is discharged into the atmosphere, the relative humidity of the flue gas is increased along with the temperature reduction (generally reduced to 50-60 ℃) and reaches a wet saturation state, namely the relative humidity reaches 100%. At the moment, when the smoke in the low-temperature and high-humidity state is discharged from the chimney and enters the atmosphere, the smoke reaches a wet saturation state, and water in the smoke is cooled and condensed to form water droplets. The small drops formed by condensation are refracted and scattered by the atmosphere to form white smoke plume which can be seen by naked eyes, namely the white smoke phenomenon of smoke occurs.

In order to eliminate or alleviate the white smoke phenomenon when the smoke is discharged, various methods are available, for example, a heating method can be adopted, namely, the smoke is heated before the smoke is discharged (a heater is arranged to directly raise the temperature of the smoke, or high-temperature gas is added to raise the temperature of the smoke), the relative humidity of the smoke is reduced, the smoke is kept in an unsaturated state, and the white smoke phenomenon is eliminated; a dehumidification method can also be adopted, namely moisture is condensed through condensation to realize flue gas dehumidification, the water content in the flue gas is reduced, the absolute moisture content of the flue gas is reduced, the flue gas is kept in an unsaturated state when being discharged, and the white smoke phenomenon is eliminated; or a dehumidification and heating method is adopted, namely, the condensation and dehumidification are firstly carried out, the absolute humidity of the smoke is reduced, and then the smoke is heated, so that the relative humidity of the smoke is reduced; and a solution dehumidification method can be adopted, namely the liquid absorbent is used for absorbing the moisture in the flue gas, and the moisture is transferred between the liquid absorbent and the flue gas by utilizing the water vapor partial pressure difference between the liquid absorbent and the flue gas, so that the latent heat of the vapor is released and absorbed and the moisture in the flue gas is recovered.

The existing method can eliminate the white smoke phenomenon during smoke emission to a certain extent, but has the defects of high cost and complex structure.

How to better eliminate or relieve the white smoke of the discharged smoke, reduce the cost and simplify the structure is a technical problem of the current technicians in the field.

Disclosure of Invention

The invention aims to provide a smoke whitening device, by which white smoke of exhausted smoke can be better eliminated or relieved, and simultaneously, the cost is lower and the structure is simple.

The invention also provides a chimney comprising the smoke whitening device and a smoke whitening method using the smoke whitening device.

The smoke whitening device provided by the invention comprises a cylinder body, wherein a smoke channel is formed in the cylinder body, and the cylinder body forms at least one air introducing channel communicated with the smoke channel and the external space of the cylinder body so as to introduce air into the smoke channel. By utilizing the smoke whitening device, air is introduced into the smoke channel through the air introduction channel and is mixed with smoke to be treated. Because the air has low water content and is relatively dry, the humidity of the smoke to be treated can be reduced, and then the smoke to be treated can be kept in an unsaturated state, so that the condensation of water can be avoided or reduced, and the aim of eliminating or reducing the white smoke phenomenon of the smoke can be fulfilled.

By utilizing the smoke whitening device, the smoke and the air can be mixed in advance before the smoke is emptied. Compared with the prior art, the flue gas whitening device is used for dividing the mixing or contact of the flue gas and the air into two stages, and the change of flue gas parameters (temperature and humidity) in the mixing process of the flue gas and the atmosphere is changed, so that the flue gas change curve is kept outside the humidity saturation curve and in an unsaturated state, and the white smoke phenomenon during the emptying of the flue gas is reduced or eliminated.

The smoke whitening device provided by the invention can realize smoke whitening by introducing air in advance only based on the air introducing channel on the cylinder, has a simple and reliable structure, and keeps lower cost.

In a further technical scheme, the air introducing channel is vertically and obliquely arranged in the direction from outside to inside, and the oblique direction is the same as the flowing direction of the smoke in the smoke channel. Therefore, the introduced air has a component vertical to the flowing direction of the flue gas, the mixture of the introduced air and the flue gas to be treated is promoted, the controllability of the flue gas parameters is improved, and the whitening effect is improved. Similarly, in the direction from outside to inside, the air introducing channel is inclined in the circumferential direction, so that the introduced air can form a rotating flow, the mixture of the introduced air and the flue gas to be treated can be promoted, the uniformity of mixing or contact is improved, the controllability of flue gas parameters is improved, and the whitening effect is improved.

In a further technical scheme, the through-flow section of the air introducing channel is gradually increased from outside to inside, so that the flow speed of introduced air is gradually reduced, the introduced air is in softer contact with flue gas, the mixing uniformity of the introduced air and the flue gas to be treated is promoted, the controllability of flue gas parameters is improved, and the whitening effect is improved.

In an alternative embodiment, the flue gas channel forms a throat section, and the inner openings of the plurality of air introduction channels are located in the throat section. Compared with the upper or lower flue gas channel, the throat section has smaller through-flow section, and the flow speed of the throat section is higher based on the fluid through-flow principle, so that the mixing of the introduced air and the flue gas to be treated can be promoted; after passing through the throat section, the through-flow section of the flue gas channel is increased, the flow speed is reduced, and the mixing uniformity of the introduced air and the flue gas to be treated can be promoted; thus, the controllability of the smoke parameters is improved, and the whitening effect is improved.

In an alternative embodiment, a rotating blade wheel is disposed in the air intake passage. The rotary vane wheel buffers the uneven introduced air caused by the change of the external environment, thereby improving the controllability of flue gas parameters and the whitening effect. For example, the air introducing channel can be further provided with a driving device for driving the rotary blade wheel to rotate, so that the rotating speed of the rotary blades can be controlled through the driving device, the quantity of introduced air can be further controlled, the controllability of flue gas parameters is improved, and the whitening effect is improved.

In an optional technical scheme, the smoke whitening device further comprises an inner scattering cylinder, wherein the inner scattering cylinder is located in the cylinder and is opposite to an inner opening of the air introducing channel, so that air can enter the smoke channel more uniformly. The scattering inner cylinder can be provided with scattering holes, so that introduced air and smoke can be mixed more softly, the controllability of smoke parameters is improved, and the whitening effect is improved.

In an optional technical scheme, in the flue gas channel, a reducing mixing section is formed at the upper end part of the uniform dispersion inner cylinder, and the through-flow section of the reducing mixing section is smaller than the inner diameter of the uniform dispersion inner cylinder so as to promote the contact and mixing of introduced air and flue gas. Further, it forms the extension guide section to all loose inner tube upper end, the extension guide section stretches into the undergauge mixing section to the homogeneity of guide air and flue gas, improvement mixture or contact.

The chimney provided by the invention comprises a flue gas introduction port, a flue gas emptying port and any one of the above flue gas blank eliminating devices, and flue gas to be treated is discharged into the atmosphere after passing through the flue gas introduction port, a flue gas channel of the flue gas blank eliminating device and the flue gas emptying port. Due to the adoption of the smoke whitening device, the chimney also has a corresponding technical effect.

According to the smoke whitening method provided by the invention, by using any one of the smoke whitening devices, before the smoke to be treated is emptied, air is introduced through the air introduction channel, so that the smoke to be treated and the air are mixed for the first time, and the relative humidity of the smoke to be treated is reduced; then, the flue gas to be treated with reduced relative humidity is evacuated. For the same reason, the white smoke phenomenon at the time of smoke emission can also be reduced or eliminated.

Drawings

Fig. 1 is a schematic cross-sectional structural view of a smoke whitening apparatus according to an embodiment of the present invention.

Fig. 2 is a schematic view of the cross-sectional structure a-a in fig. 1.

FIG. 3 is a schematic diagram of the variation trajectory of the moisture content and temperature of the flue gas, including the theoretical trajectory of the evacuation of the flue gas, the trajectory of the normal evacuation of the flue gas, and the trajectory of the flue gas after mixing air according to the present invention.

Fig. 4 is a schematic vertical half-section structure diagram of a smoke whitening device according to another embodiment of the invention.

Fig. 5 is a schematic cross-sectional view of a smoke whitening apparatus according to an embodiment of the present invention.

Fig. 6 is a schematic vertical sectional structural diagram of a smoke whitening device according to an embodiment of the present invention.

Fig. 7 is a schematic vertical sectional structural view of a smoke whitening device according to another embodiment of the invention.

Fig. 8 is a schematic vertical sectional view of a smoke whitening apparatus according to another embodiment of the invention.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings.

It should be noted that:

1. in this document, the terms of orientation such as "upper", "lower", "inner" and "outer" refer to the specific application scenario of the smoke whitening device or the chimney.

2. "whitening" is understood by those skilled in the art to include, in addition to the elimination of white smoke phenomena, the reduction of white smoke phenomena.

Referring to fig. 1 and fig. 2, fig. 1 is a schematic cross-sectional view illustrating a smoke whitening apparatus according to an embodiment of the invention, wherein a smoke channel 110 extends in a vertical direction to allow smoke to flow from bottom to top. Fig. 2 is a schematic view of the cross-sectional structure a-a in fig. 1.

The smoke whitening apparatus provided by this embodiment comprises a cylinder 100, a smoke channel 110 is formed in the cylinder 100, and at least one air introducing channel 120 communicating the smoke channel 110 and the space outside the cylinder 100 is formed in the cylinder 100 to introduce air into the smoke channel 110.

With this flue gas whitening means, air is introduced into the flue gas channel 110 through said air introduction channel 120 and mixed with the flue gas to be treated.

Referring to fig. 3, fig. 3 is a schematic diagram showing the variation trace of the moisture content of the flue gas and the temperature, wherein the moisture content is the moisture content existing in a gaseous state. In the figure, a theoretical trajectory of smoke evacuation, a trajectory of smoke evacuation in normal evacuation, and a trajectory of smoke after air mixing in the present patent are illustrated. According to the theoretical trajectory (wet saturation line) of the exhaust of the flue gas, as the temperature decreases, the moisture content of the flue gas also decreases, namely the absolute moisture content in the flue gas decreases with the temperature; excess moisture will condense to form water droplets. When the smoke is normally exhausted, the change track of the smoke is intersected with the theoretical track line, the intersection points are A and B, when the smoke parameter is positioned between A and B, the moisture of the smoke exists in a supersaturated state, and part of the moisture is condensed into water drops, namely, the white smoke phenomenon occurs. By utilizing the smoke white elimination device provided by the invention, smoke is contacted with air in advance in the smoke white elimination device, the proportion of the air and the smoke is properly controlled, and the smoke parameters can be changed along the Y-H line. After passing through the smoke whitening device, the smoke is evacuated, and the evacuation process is carried out to ensure that the smoke changes along an H-C line, so that the smoke state is positioned above a theoretical trajectory line (wet saturation line), namely, the moisture in the smoke is prevented from being condensed, and the white smoke phenomenon is avoided or reduced.

The smoke white elimination device provided by the invention can realize smoke white elimination by introducing air in advance only based on the air introduction channel 120 on the cylinder body 100, has a simple and reliable structure, and keeps lower cost.

The air introduction passage 120 may be provided in plurality, and the plurality of air introduction passages 120 may be uniformly provided. According to the position, the climate and the wind direction of the place, the device can also be arranged unevenly so as to ensure the mixing and the contact of the introduced air and the flue gas. Of course, the air introducing channels 120 may be arranged in sequence in the flow direction of the flue gas, so that the flue gas is contacted twice, three times or more before being emptied, so as to change the variation track of the flue gas parameters, so that the flue gas state is located above the theoretical trajectory line (wet saturation line), the unsaturated state is maintained, the white smoke phenomenon is avoided, or the white smoke phenomenon is reduced.

The air introduction passage 120 may be a through hole perpendicular to the center of the flue gas passage 110 and may have a corresponding inclination angle. As shown in fig. 4, the figure is a schematic vertical half-section structure diagram of a smoke whitening device provided by another embodiment of the invention. The air introduction passage 120 may be vertically inclined in the outside-in direction, the inclined direction being the same as the flow direction of the flue gas in the flue gas passage 110. Therefore, the introduced air has a component vertical to the flowing direction of the flue gas, the mixture of the introduced air and the flue gas to be treated is promoted, the controllability of the flue gas parameters is improved, and the whitening effect is improved. In this embodiment, in the direction from outside to inside, the through-flow cross section of the air introducing passage 120 may be gradually increased, so that the flow speed of the introduced air may be gradually decreased, the introduced air may be in softer contact with the flue gas, the mixing uniformity of the introduced air and the flue gas to be treated may be promoted, the controllability of the flue gas parameters may be improved, and the whitening effect may be improved. Of course, the flow cross section of the air introduction channel 120 can be made to have a suitable flow cross section or a suitably shaped flow cross section to meet the actual requirements.

In addition, as shown in fig. 5, a schematic diagram of a transverse cross-sectional structure of a smoke whitening apparatus according to an embodiment of the present invention is provided. In the direction from outside to inside, the air introducing channels 120 may be inclined in the circumferential direction, and then the introduced air forms a rotational flow through the plurality of air introducing channels 120, which may also promote the mixing of the introduced air and the flue gas to be treated, improve the uniformity of mixing or contact, improve the controllability of flue gas parameters, and improve the whitening effect.

Fig. 6 is a schematic vertical sectional view of a smoke whitening apparatus according to an embodiment of the invention, in which the smoke channel 110 forms a throat section 111, i.e. a portion with a relatively small flow cross section, and the upper flow cross section and the lower flow cross section of the smoke whitening apparatus are both larger than the flow cross section of the portion. Throat section 1111) has a minimum flow cross-sectional area of 40% -85% of the upper flow cross-sectional area, and the lower flow cross-sectional area may be equal to the upper flow cross-sectional area. Wherein the inner openings of the plurality of air introduction channels 120 are located at the throat section 111, and preferably, the inner openings of the plurality of air introduction channels 120 are all located at the smallest cross-sectional flow area of the throat section 111. Based on the fluid through-flow principle, the through-flow section of the throat section 111 is smaller, the smoke flow speed is higher, and the pressure is lower, so that the mixture of introduced air and smoke to be treated can be promoted; after passing through the throat section 111, the through-flow section of the flue gas channel 110 is increased, the flow speed is reduced, and the mixing uniformity of the introduced air and the flue gas to be treated can be promoted; thus, the controllability of the smoke parameters is improved, and the whitening effect is improved.

In a preferred embodiment, a rotary blade wheel is disposed in the air introduction passage 120. When the external atmospheric pressure is suddenly increased, the rotary vane wheel can overcome the flowing of external air to rotate, so that the buffer effect is achieved; when external atmospheric pressure suddenly reduces, because the inertia effect of rotating vane wheel, can produce the suction effect, and then improve and introduce the air homogeneity, and then improve the controllability of flue gas parameter, improve the effect of eliminating white. For example, the air introducing passage 120 may further include a driving device for driving the rotary blade wheel to rotate, so that the driving device may control the rotation speed of the rotary blades, and further may control the amount of the introduced air, thereby improving the controllability of the flue gas parameters and the whitening effect.

Fig. 7 is a schematic vertical sectional view of a smoke whitening apparatus according to another embodiment of the invention. In this white device of flue gas disappears, the white device of flue gas disappears still includes and all looses inner tube 200, it is located all to loose inner tube 200 in barrel 100, and with the internal orifice of air introduction passageway 120 is relative, so that the clearance entering flue gas passageway between the outer wall of introducing the air through air introduction passageway 120 through all loosing inner tube 200 and the inner wall of barrel 100 to all loose inner tube 200 upper end 360 degrees within ranges and mix with the flue gas, and then more evenly get into flue gas passageway 110. The scattering inner cylinder 200 can be provided with scattering holes, so that introduced air can be mixed with smoke more softly through the scattering holes, the controllability of smoke parameters is improved, and the whitening effect is improved.

As shown in fig. 8, a schematic vertical sectional structure of another smoke whitening apparatus is provided, in a smoke channel 110 of the smoke whitening apparatus, a reducing mixing section 112 is formed at an upper end portion of the scattering inner cylinder 200, and a through-flow cross section of the reducing mixing section 112 is smaller than an inner diameter of the scattering inner cylinder 200 to promote contact and mixing of the introduced air and the smoke. The upper end of the dispersing inner barrel 200 can be formed with an extension guide section 300, and the extension guide section 300 extends into the diameter-reducing mixing section to guide the mixing of air and flue gas and improve the uniformity of mixing or contact.

The chimney provided by the invention comprises a flue gas introduction port, a flue gas emptying port and any one of the above flue gas blank eliminating devices, and flue gas to be treated is discharged into the atmosphere after passing through the flue gas introduction port, a flue gas channel 110 of the flue gas blank eliminating device and the flue gas emptying port. Due to the adoption of the smoke whitening device, the chimney also has a corresponding technical effect. The cylinder 100 of the smoke and white elimination device can be integrally formed with a chimney or assembled with the chimney through installation.

According to the smoke whitening method provided by the invention, any one of the smoke whitening devices can be utilized, before the smoke to be treated is emptied, air is introduced through the air introducing channel 120, so that the smoke to be treated and the air are mixed for the first time, and the relative humidity of the smoke to be treated is reduced; then, the flue gas to be treated with reduced relative humidity is evacuated, even if the flue gas and the air are mixed and contacted for two times or more, the parameters of the flue gas are kept above the temperature saturation trajectory, namely, the flue gas is kept in an unsaturated state, and then the white smoke phenomenon during flue gas emission is reduced or eliminated, and the specific principle is not repeated.

The foregoing has outlined rather broadly the embodiments of the present invention. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the core concepts of the present invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims (10)

1. A smoke whitening apparatus comprising a barrel (100), a smoke channel (110) being formed in said barrel (100), characterized in that said barrel (100) is formed with at least one air introduction channel (120) communicating said smoke channel (110) and a space outside said barrel (100) to introduce air into said smoke channel (110).

2. The flue gas whitening device according to claim 1, wherein the air introduction channel (120) is vertically inclined in the outside-in direction, the direction of inclination being the same as the flow direction of the flue gas in the flue gas channel (110); and/or the first and/or second light sources,

in the outward-inward direction, the air introduction passage (120) is circumferentially inclined.

3. The flue gas whitening device according to claim 1, characterized in that the through-flow cross-section of the air introduction channel (120) increases gradually in the outward-inward direction.

4. The smoke whitening device according to claim 1, wherein said smoke passage (110) forms a throat section (111), and inner mouths of a plurality of said air introduction passages (120) are located at said throat section (111).

5. The smoke whitening device according to claim 1, characterized in that a rotating vane wheel is provided in the air introduction channel (120).

6. The smoke whitening device according to any one of claims 1 to 5, further comprising a scattering inner cylinder (200), wherein said scattering inner cylinder (200) is located inside said cylinder (100) and is opposite to the inner opening of said air introduction channel (120).

7. The smoke whitening device according to claim 6, characterized in that the scattering inner cylinder (200) is provided with scattering holes.

8. The smoke whitening device according to claim 7, wherein a reduced diameter mixing section (112) is formed in the upper end portion of the scattering inner cylinder (200) in the smoke channel (110), and the through-flow cross section of the reduced diameter mixing section (112) is smaller than the inner diameter of the scattering inner cylinder (200).

9. A chimney comprising a flue gas introduction port and a flue gas evacuation port, characterized by comprising the flue gas whitening apparatus of any one of claims 1 to 8, wherein flue gas to be treated is evacuated to the atmosphere after passing through the flue gas introduction port, a flue gas channel (110) of the flue gas whitening apparatus and the flue gas evacuation port.

10. A smoke whitening method is characterized by comprising the following steps:

with the smoke whitening apparatus as defined in any one of claims 1 to 9, introducing air through said air introduction passage (120) before the smoke to be treated is evacuated, so that the smoke to be treated is subjected to a first mixing with the air, and the relative humidity of the smoke to be treated is reduced; then, the flue gas to be treated with reduced relative humidity is evacuated.

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