KR102059190B1 - Mist eliminator and wet flue gas desulfurization apparatus including the same - Google Patents

Abstract

The present invention is a mist eliminator (Mist Eliminator) by absorbing the mist (moisture) contained in the exhaust gas by the capillary phenomenon, the mist is effectively removed, the mist eliminator that can minimize the height of the desulfurization apparatus and wet flue gas desulfurization comprising the same Relates to a device.

Description

Mist eliminator and wet flue gas desulfurization apparatus including the same {MIST ELIMINATOR AND WET FLUE GAS DESULFURIZATION APPARATUS INCLUDING THE SAME}

The present invention relates to a mist eliminator and a wet flue gas desulfurization apparatus, and more particularly, a mist eliminator absorbs mist (moisture) contained in exhaust gas by capillary action, thereby effectively eliminating mist. It relates to a mist eliminator and a wet flue gas desulfurization apparatus including the same to minimize the height.

In the boiler, combustion is carried out by injecting fossil fuel, such as coal, and air containing excess oxygen, and as a result of combustion, fly ash, carbon dioxide (CO2), nitrogen oxides (NOx), and sulfur oxides ( By-products such as SOx), carbon monoxide (CO), and unburned carbon powder (HC) are generated together with heat, and unreacted nitrogen (N2) and oxygen (O2) remain.

As such, when the fuel containing sulfur is burned, sulfur is released to the atmosphere in the form of sulfur dioxide (SO2), except that it is attached to ash. This sulfur dioxide causes air pollution and causes acid rain on the earth, which has a detrimental effect on the environment as well as the human body and animals.

To this end, large-scale incineration plants and power plants have been usually equipped with an exhaust gas desulfurization unit, most of which are wet flue gas desulfurization units.

In a wet desulfurization process, the exhaust gas is gas-liquid contacted with an absorbing fluid containing an alkali such as lime, whereby sulfur dioxide is absorbed and removed from the exhaust gas. At this time, although the gas is classified into various types according to the gas-liquid contact method of the exhaust gas and the absorbing fluid, a spray method of contact is widely used worldwide.

As a result, sulfur dioxide absorbed from the exhaust gas forms sulfite in the absorbing fluid, which is typically oxidized by blowing air into the absorbing fluid to form gypsum as a byproduct.

That is, a wet flue gas desulfurization device is a type of so-called oxidation tank, where air is blown into the tank, where the air comes into contact with an absorbing fluid with absorbed sulfur dioxide inside the tank.

Looking at the conventional wet flue gas desulfurization apparatus disclosed in the Republic of Korea Utility Model Publication No. 1998-0030926, the exhaust gas is introduced into the absorption tower (1) through the inlet duct, the absorption tower (1) in the circulation pump (3) The absorbing liquid containing calcium carbonate supplied by the spray is sprayed in the spray nozzle 2 to make gas-liquid contact between the absorbing liquid and the exhaust gas. The absorbent liquid selectively absorbs sulfur dioxide in the exhaust gas to produce calcium sulfite, and the calcium sulfite (CaSO3) in the absorbent liquid is oxidized by oxygen in the air supplied to the absorption tower circulation tank 4 by the air suction pipe 6. To produce gypsum.

In addition, the exhaust gas in which sulfur dioxide is absorbed and removed is discharged through the outlet duct, and is discharged after the vapor (moisture) accompanying the exhaust gas is removed by the mist remover 7.

However, the conventional mist eliminator is generally made of a plate of SUS-based material, there is a limit such as the exhaust gas flow rate for preventing carry-over of the mist, to improve the moisture-gas separation efficiency of the mist eliminator Several methods are being studied.

Korean Utility Model Publication No. 1998-0030926 (August 17, 1998 release)

The present invention is a mist eliminator (Mist Eliminator) by absorbing the mist (moisture) contained in the exhaust gas by the capillary phenomenon, the mist is effectively removed, the mist eliminator that can minimize the height of the desulfurization apparatus and wet flue gas desulfurization comprising the same It is an object to provide a device.

The present invention for solving the above problems, the absorption tank containing the absorbent solution containing the alkaline absorber, the absorption tower extending to the upper portion of the absorption tank, the exhaust gas inlet duct provided on one side of the absorption tower, An exhaust gas outlet duct provided on the other side of the absorption tower, a spray installed in the absorption tower for spraying the absorption liquid, a circulation pump for supplying the absorption liquid in the absorption tank to the spray, and the absorption tank Oxygen supply pipe for supplying an oxygen-containing gas to the mist and a mist remover for removing the mist (mist) contained in the exhaust gas discharged to the outlet duct, the mist eliminator absorbs the mist by the capillary phenomenon, wet smoke Provide a desulfurization device.

The mist eliminator may include a pair of plates and a fiber layer bonded between the pair of plates.

The fiber layer may be made of hollow fibers.

The fiber layer may be made of fibers with high hygroscopicity.

In addition, according to another embodiment of the present invention, the mist eliminator is coupled to the flat sheet-like first sheet and the first sheet to form a plurality of flow paths, and may include a corrugated second sheet made of fibers. have.

The first sheet and the second sheet may be laminated at least once.

The first sheet may be made of a metal material.

In addition, according to another embodiment of the present invention, the first sheet may be made of fibers.

The first sheet and the second sheet may be made of fibers having high hygroscopicity.

The apparatus may further include a dehydration unit for dewatering the mist absorbed by the mist eliminator.

The dewatering unit may include a blower (fan).

In addition, according to another embodiment of the present invention, the dewatering unit may vibrate or rotate the mist eliminator.

In addition, according to another embodiment of the present invention, there is provided a mist eliminator comprising a pair of plates and a fiber layer bonded between the pair of plates.

In addition, according to another embodiment of the present invention, it is provided with a mist eliminator comprising a plate-shaped first sheet and a plurality of flow paths coupled to the first sheet and comprising a corrugated second sheet made of fibers.

According to the present invention, the mist eliminator can absorb the mist contained in the exhaust gas by capillary action to quickly absorb the mist, thereby minimizing the height of the desulfurization apparatus by installing the mist eliminator near the spray of the desulfurization apparatus. can do.

The effects of the present invention are not limited to the above-described effects, but should be understood to include all the effects deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a schematic view showing a wet flue gas desulfurization apparatus according to a first embodiment of the present invention.
FIG. 2 is a front view illustrating the mist eliminator of FIG. 1 viewed from A; FIG.
3 is a perspective view showing a mist eliminator according to a second embodiment of the present invention.
4 is a perspective view showing a mist eliminator according to a third embodiment of the present invention.
5 is an enlarged view of a portion of FIG. 4.

Hereinafter, preferred embodiments of the mist eliminator and the wet flue gas desulfurization apparatus of the present invention will be described with reference to the accompanying drawings.

In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to intentions or customs of users or operators, and the following embodiments do not limit the scope of the present invention. It is merely illustrative of the components set forth in the claims.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and like reference numerals designate like elements throughout the specification. Throughout the specification, when a part is said to "include" a certain component, it means that it may further include other components, without excluding the other components unless otherwise stated.

The wet flue gas desulfurization apparatus of the present invention is for removing sulfur oxides (mostly sulfur dioxide (SO 2)) from exhaust gases such as boilers by gas-liquid contact between absorption liquid and exhaust gas.

First, with reference to Figure 1 to look at the wet flue gas desulfurization apparatus according to an embodiment of the present invention.

Wet flue gas desulfurization apparatus according to an embodiment of the present invention is largely, absorption tank 100, absorption tower 200, exhaust gas inlet duct 210, exhaust gas outlet duct 220, spray 300, circulation pump 320, an oxygen supply pipe 400, a mist remover 500, a by-product discharge unit 600, and a dehydration unit 700 may be formed.

Specifically, the absorption tank 100 is stored in the absorbent solution containing an alkaline absorbent, in this embodiment limestone (CaCO3) is used as the alkaline absorber. The absorption tank 100 may be formed to have a variety of cross-sections, such as circular or square, in the present embodiment will be described based on the square absorption tank.

The absorption tower 200 extends to the upper portion of the absorption tank 100 and may be formed integrally with the absorption tank 100.

One side of the absorption tower 200 is provided with an exhaust gas inlet duct 210 for introducing the exhaust gas, and the other side of the absorption tower 200 has an exhaust gas outlet duct 220 for discharging the purified exhaust gas. Is provided.

In the present embodiment, the inlet duct 210 is provided on the lower left side of the absorption tower 200 based on FIG. 1, and the outlet duct 220 is provided on the upper right side of the absorption tower 200. .

The positions of the inlet duct 210 and the outlet duct 220 are not limited thereto, but after the exhaust gas flowing through the inlet duct 210 comes into contact with an absorption solution sprayed by the spray 300 to be described later. Preferably, the outlet duct 220 may be discharged through the outlet duct 220.

A spray 300 for spraying the absorption solution is installed in the absorption tower 200, and the circulation pump 320 recovers the absorption solution in the absorption tank 100 and supplies it to the spray 300. It is for.

In this embodiment, the spray 300 is provided above the inlet duct 210, the exhaust gas flowing into the absorption tower 200 through the inlet duct 210 to the upper portion of the absorption tower 200. It flows and is discharged to the outlet duct 220 through the spray 300.

Accordingly, the absorbing solution which is lifted by the circulation pump 320 and sprayed through the spray 300 and the exhaust gas introduced through the inlet duct 210 come into gas-liquid contact, and the absorbing solution is exhausted. It absorbs sulfur dioxide present in the gas.

Specifically, the absorption tower 200 is made as follows.

(1) SO2 + H2O → H + + HSO3-

In this case, the spray 300 is preferably formed uniformly at all positions in the cross section of the absorption tower 200 so that the exhaust gas passing through the absorption tower 200 does not come into contact with the absorption solution. Do.

Accordingly, the exhaust gas from which sulfur dioxide is removed is discharged through the outlet duct 220, and the absorbing solution absorbing sulfur dioxide falls back into the absorption tank 100.

At this time, the exhaust gas flowing through the spray 300 toward the outlet duct 220 contains a large amount of water (mist), the mist eliminator 500 is installed to absorb and remove it.

In the present embodiment, the mist eliminator 500 is provided between the spray 300 and the outlet duct 220 in the absorption tower 200, but is not limited thereto and is installed on the outlet duct 220. May be

In the present invention, the mist eliminator 500 is characterized in that to absorb the mist by the capillary phenomenon, the mist eliminator 500 will be described in detail below.

The absorption tank 100 is provided with an oxygen supply pipe 400 for supplying an oxygen-containing gas, in this embodiment air.

As air is supplied into the absorption solution of the absorption tank 100 by the oxygen supply pipe 400, an oxidation reaction of sulfite in the absorption tank 100, and CaSO 3 in the present embodiment, is performed as a by-product. Gypsum (CaSO 4 .2H 2 O) is formed. The gypsum thus formed is suspended in the absorbent solution and sinks to the lower side of the absorbent tank 100.

Hereinafter, in the absorption tank 100, the following reactions are made.

(2) H + + HSO3- + 1/2 O2 → 2H + + SO42-

(3) 2H + + SO42- + CaCO3 + H2O → CaSO4, 2H2O + CO2

The oxygen supply pipe 400 may be arranged to be spaced apart from each other along the circumferential direction of the absorption tank 100, inclined in the same direction along the circumferential direction of the absorption tank 100.

That is, the oxygen supply pipe 400 is not installed vertically at the tangential point at which the oxygen supply pipe 400 is installed, based on the cross section of the absorption tank 100, and is installed to have a constant angle in the same direction. Will be.

Accordingly, the absorption solution may be agitated by the air supplied through the plurality of oxygen supply pipes 400 without a separate stirrer. As such, as the rotational flow is formed in the absorption tank 100, the contact time between the air supplied through the oxygen supply pipe 400 and the absorption liquid may be further extended.

However, the present invention is not limited thereto and may include a separate stirrer for stirring the absorption solution in the absorption tank 100.

The by-product discharge part 600 for discharging the gypsum generated as described above is provided in the lower portion of the absorption tank 100. The by-product discharge unit 600 includes a discharge pump 620 and a solid-liquid separator 640, so that the absorbent solution containing gypsum is recovered by the discharge pump 620, the solid-liquid separator 640 It can be introduced into, so that the absorbed sulfur dioxide can be completely removed by separating the solid material gypsum and filtrate.

Furthermore, the filtrate may be transferred to a filtration tank (not shown), mixed with lime, and then returned to the absorption tank 100.

Hereinafter, the mist eliminator 500 will be described in detail with reference to FIG. 2.

The mist eliminator 500 may include a pair of plates 520 and a fiber layer 540 coupled between the pair of plates 520.

In this embodiment, the fiber layer 540 is made of hollow fibers (hollow fiber), the hollow fiber refers to a fiber having pores therein. That is, as shown in FIG. 2, a plurality of continuous or discontinuous hollows 542 are formed in the fiber layer 540.

In this case, the fiber layer 540 may be made of a fiber having high hygroscopicity. For example, it can be a natural fiber, regenerated fiber, etc. with high hygroscopicity.

Accordingly, the mist accompanying the exhaust gas passing through the mist eliminator 500 may be rapidly absorbed into the fiber layer 540 through capillary action through the plurality of hollows 542.

In addition, as the mist accompanying the exhaust gas passing through the spray 300 is quickly and effectively absorbed through the fiber layer 540 of the mist eliminator, the mist eliminator 500 may be installed close to the spray 300. Therefore, the overall height of the desulfurization apparatus may be reduced as compared with the related art, and there is no limitation in the flow rate of the exhaust gas passing through the mist eliminator 500 or the limited flow rate is higher than in the related art.

Furthermore, by forming the fibrous layer with adsorbable fibers, for example, activated carbon fibers, sulfur trioxide (SO3), etc. still remaining in the exhaust gas passing through the spray 300 may be removed through adsorption.

In addition, the mist eliminator 500 may further include a dehydration unit 700 for dewatering the mist absorbed by the mist eliminator.

The dewatering unit 700 may be installed on the side facing the mist eliminator 500 or the side of the mist eliminator 500, and as shown in FIG. 1 in the present embodiment, the mist eliminator 500 is provided. It is installed inside the absorption tower 200 facing the.

The dewatering unit 700 may include a blower (fan), it is possible to dehydrate the mist absorbed in the mist eliminator 500 by blowing.

However, since the flow rate of the exhaust gas may be increased by blowing when the dewatering part 700 is formed as a blower, when wet desulfurization is not performed, that is, the exhaust gas is not introduced into the absorption tower 200. It is preferable to dehydrate the mist absorbed in the mist eliminator 500 by operating the blower.

However, the present invention is not limited thereto, and according to another exemplary embodiment, the dewatering part may be dehydrated by vibrating or twisting the mist eliminator 500.

For example, the mist eliminator 500 or the fiber layer 540 thereof is installed to vibrate or rotate in one direction in the absorption tower 200, and the dewatering part includes a driving device for vibrating or rotating the same. It can be done by.

Next, the mist eliminator 1500 according to the second embodiment of the present invention will be described with reference to FIG. 3.

The mist eliminator 1500 is coupled to the flat sheet-like first sheet 1520 and the first sheet 1520 to form a plurality of flow paths 1530, and the second sheet-shaped sheet 1540 having a corrugated shape made of fiber. It may include.

The first sheet 1520 and the second sheet 1540 may be stacked at least one or more times. In the present embodiment, as shown in FIG. 3, the plurality of first sheets 1520 and the plurality of second sheets ( 1540 are stacked alternately.

The first sheet 1520 may be made of a metal material, for example, a stainless material, but is not limited thereto. The first sheet 1520 may be made of fiber in the same manner as the second sheet 1540. It may be made of.

The second sheet 1540 is formed to have a V-shaped bend and is coupled to the first sheet 1520 to form a plurality of flow paths 1530 therebetween. In this case, the mist eliminator 1500 is installed such that the longitudinal direction of the plurality of flow paths 1530 is the same as the direction in which the exhaust gas passing through the spray 300 flows upward in the absorption tower 200. Preferably, the exhaust gas passing through the spray 300 may pass along the plurality of flow paths 1530 of the mist eliminator.

The first sheet 1520 or the second sheet 1540 may be formed of fibers having high hygroscopicity. For example, it can be a natural fiber, regenerated fiber, etc. with high hygroscopicity.

Accordingly, while the exhaust gas passing through the spray 300 passes through the plurality of flow paths 1530 of the mist eliminator, the mist accompanying the exhaust gas is capillary and thus, the first sheet 1520 and the second sheet 1540. ) Can be quickly absorbed, and the same effect as in the first embodiment can be obtained.

Further, at least one of the first sheet and the second sheet is formed of adsorbable fibers, for example, activated carbon fibers, so that sulfur trioxide (SO 3), which is still remaining in the exhaust gas passing through the spray 300, is adsorbed. Can be removed via

Next, the mist eliminator 2500 according to the third embodiment of the present invention will be described with reference to FIGS. 4 and 5.

As described in the second embodiment, the mist eliminator 2500 is coupled to the flat sheet-like first sheet 2520 and the first sheet 2520 to form a plurality of flow paths 2530. The second sheet 2540 having a corrugated shape may be formed.

However, the second sheet 2540 is formed to have a U-shaped bend and is coupled to the first sheet 2520 to form a plurality of flow paths 2530 therebetween.

Furthermore, as shown in FIG. 5, minute unevenness 2542 is formed in the second sheet 2540 to increase the surface area. As a result, an area in contact with the exhaust gas passing through the plurality of flow paths 2530 is increased. It's getting wider.

Accordingly, the same effects as those of the second embodiment can be obtained, and as the surface area of the second sheet 2540 is wider, the absorption efficiency of mist is increased.

In the present invention, the structure of the mist eliminator is not limited to the above embodiment, and may be formed in various structures for absorbing mist by capillary action such as a corrugated structure and a honeycomb structure.

According to the present invention, the mist eliminator can absorb the mist contained in the exhaust gas by the capillary phenomenon, so that the mist can be quickly absorbed, thereby minimizing the height of the desulfurization apparatus by installing the mist eliminator at a position close to the spray of the desulfurization apparatus. can do.

In the above embodiment, the mist eliminator has been described based on the application to the wet flue gas desulfurization apparatus, but the present invention is not limited thereto. The mist eliminator of the present invention may be any apparatus for removing mist (moisture) contained in gas. Can be applied.

The present invention is not limited to the above-described specific embodiments and descriptions, and various modifications can be made by those skilled in the art without departing from the gist of the present invention claimed in the claims. Such variations are within the protection scope of the present invention.

100: absorption tank 200: absorption tower
210: exhaust gas inlet duct 220: exhaust gas outlet duct
300: spray 320: circulation pump
400: oxygen supply pipe 600: by-product discharge unit
620: discharge pump 640: solid-liquid separator
700: dehydration part
[First Embodiment]
500: mist eliminator 520: a pair of plates
540: fiber layer 542 hollow
Second Embodiment
1500: mist eliminator 1520: first sheet
1530: plurality of flow paths 1540: second sheet
Third Embodiment
2500: mist eliminator 2520: first sheet
2530: plurality of flow passages 2540: second sheet
2542: unevenness

Claims (20)

An absorption tank in which an absorbing solution containing an alkaline absorbent is stored;
An absorption tower extending to an upper portion of the absorption tank;
An exhaust gas inlet duct provided at one side of the absorption tower;
An exhaust gas outlet duct provided on the other side of the absorption tower;
A spray installed in the absorption tower to spray the absorption solution;
A circulation pump for supplying the absorption liquid in the absorption tank to the spray;
An oxygen supply pipe for supplying an oxygen-containing gas to the absorption tank; And
And a mist eliminator for removing mist contained in exhaust gas discharged through the outlet duct.
The mist eliminator absorbs mist by capillary action,
The mist eliminator is
A flat sheet-shaped first sheet; And
And a second sheet having a corrugated shape formed of fibers, coupled to the first sheet to form a plurality of flow paths through which the exhaust gas passing through the spray passes.
Wet flue gas desulfurization apparatus, wherein the first sheet and the second sheet are laminated at least once. delete delete delete delete delete The method of claim 1,
The first sheet is made of a metal material, wet flue gas desulfurization apparatus. The method of claim 1,
The first sheet is made of fibers, wet flue gas desulfurization apparatus. The method of claim 8,
The first sheet and the second sheet is a wet flue gas desulfurization apparatus made of a fiber having high hygroscopicity. The method of claim 1,
A dewatering part for dewatering the mist absorbed by the mist eliminator;
Further comprising, a wet flue gas desulfurization apparatus. The method of claim 10,
The dehydration unit comprises a blower (fan), wet flue gas desulfurization apparatus. The method of claim 10,
The dewatering unit vibrates or rotates the mist eliminator, wet flue gas desulfurization apparatus. delete delete delete A flat sheet-shaped first sheet; And
And a second sheet having a corrugated shape formed of a fiber, the plurality of flow paths being coupled to the first sheet to allow a gas containing moisture to pass therethrough.
Wherein said first sheet and second sheet are laminated at least once. delete The method of claim 16,
The first sheet is made of a metal material, mist eliminator. The method of claim 16,
And said first sheet is made of fibers. The method of claim 19,
Wherein said first sheet and second sheet are made of fibers with high hygroscopicity.

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