JPH0824569A - Method for desulfurizing waste gas and device therefor - Google Patents

Abstract

PURPOSE:To economically remove sulfur dioxide in a waste gas with high efficiency by providing the device with a liq. dispersing mechanism in a riser and injecting a liq. downward as a liq. droplet from the mechanism into the ascending waste gas so that the liq. droplet flows downward and then upward. CONSTITUTION:A waste gas is brought into contact with a processing liq. L, treated, then collected in a riser 4, transferred into an upper space at a high velocity and desulfurized, and, in this case, liq. dispersing mechanisms 8 to 11, 18, 20 and 20' are arranged in the riser 4. The liq. is injected downward as a liq. droplet from the mechanisms into the ascending waste gas so that the liq. droplet flows downward and then upward. Further, a waste gas collision plate 7 is furnished above the outlet of the riser 4, and the waste gas ascending in the riser 4 and contg. the liq. droplet is made to collide with the lower face of the plate 7. As a result, the sulfur dioxide in the waste gas is easily removed with high efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a desulfurization treatment method and a desulfurization treatment apparatus for exhaust gas.

[0002]

2. Description of the Related Art Exhaust gas is introduced into a second chamber of a closed tank which is divided into three chambers, and from this second chamber, a first chamber located below the second chamber through a number of gas introducing pipes. After being introduced into the treatment liquid of (1) and treated, the treated exhaust gas passes through the first chamber to the second chamber and passes through the riser which communicates with the third chamber located above the second chamber. An exhaust gas desulfurization treatment device having a structure in which it is transferred to three chambers at high speed is known. On the other hand, regarding exhaust gas released into the air, regulations on pollutants contained therein are becoming more and more strict, and for example, it is required to keep the SO ₂ concentration in the exhaust gas at 20 ppm or less. Therefore, with the tightening of regulations on exhaust gas, there has been a strong demand for improvement in performance of the exhaust gas treatment apparatus, and many studies have been directed to the improvement of the performance. However, the improvement in performance is practically close to the limit due to economic constraints, which is a very difficult problem to solve.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a desulfurization method and a desulfurization treatment apparatus for exhaust gas, which can remove sulfurous acid gas contained in the exhaust gas with high efficiency and economically.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, in the desulfurization treatment method of exhaust gas having a step of collecting the treated exhaust gas after contacting the treatment liquid with the riser and transferring it to the upper space at high speed, a liquid dispersion mechanism is provided in the riser. When the liquid is jetted downward as droplet particles into the exhaust gas rising from the liquid dispersion mechanism, the droplet particles are jetted so as to move downward and then change the flow path upward. A method for desulfurizing exhaust gas is provided.

Further, according to the present invention, in the exhaust gas desulfurization device having a riser for collecting the treated exhaust gas after contacting it with the treatment liquid and transferring it to the upper space at high speed, in the riser where the exhaust gas rises. An exhaust gas desulfurization treatment apparatus is provided, which is provided with a liquid dispersion mechanism that ejects a liquid downward so that ejected droplet particles travel downward and then change a flow path upward. .

Next, the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic diagram of an exhaust gas desulfurization treatment apparatus of the present invention.
In FIG. 1, 1 is a closed tank that constitutes the main body of an exhaust gas treatment device, 2 is an exhaust gas supply pipe, 3 is a gas introduction pipe (sparger pipe), 4 is a riser, and 5 is between the first chamber and the second chamber. First partition plate, 6 is a second partition plate between the second chamber and the third chamber, 7 is an exhaust gas collision plate, 8 to 11 and 18, 20, 2
0'is a liquid dispersion mechanism, 12 to 15 and 19, 21 are liquid supply pipes, 16 is a gas discharge pipe, 17 is a mist eliminator,
a is the first chamber, b is the second chamber, c is the third chamber, and L is the exhaust gas treatment liquid.

In order to desulfurize the exhaust gas by using the apparatus shown in FIG. 1, the exhaust gas is introduced from the exhaust gas supply pipe 2 into the second chamber b, and from the second chamber b via the gas introduction pipe 3. The exhaust gas is discharged into the treatment liquid L in the first chamber a adjacent to the lower side of the two chambers b to bring the exhaust gas into contact with the treatment liquid, and the sulfur dioxide gas in the exhaust gas is absorbed by the exhaust gas treatment liquid to be removed from the exhaust gas.
Exhaust gas from which sulfur dioxide has been removed is riser 4
Rises inside. In the riser 4, the upper end thereof projects from the surface of the second partition plate 6, and liquid is retained between the surface of the second partition plate 6 and the upper end of the riser 4. This stagnant liquid flows down from the upper end of the riser 4 along the peripheral wall thereof into the first chamber a or is discharged to the outside of the closed tank 1 through a pipe. The cross section of the riser 4 can be various shapes such as a circle, a square, and a rectangle. Liquid dispersion mechanisms (spray nozzles, etc.) 20 and 20 'according to the present invention are arranged in the riser 4, and liquid is jetted downward, and exhaust gas rising in the riser is jetted from this liquid dispersion mechanism. The riser 4 rises into the third chamber c in a state where the riser 4 is in contact with the generated droplet particles and collides with the lower surface of the exhaust gas collision plate 7 disposed above the upper end of the riser. To do. The liquid dispersion mechanism arranged in the riser 4 can be arranged in two stages as shown in FIG. 1, or can be arranged in one or three stages.

When the exhaust gas containing droplet particles collides with the exhaust gas collision plate 7, the droplet particles in the exhaust gas are separated from the exhaust gas and adhere to the lower surface of the collision plate, and a liquid film is formed on the lower surface of the collision plate. . This liquid film flows down along the lower surface of the collision plate,
It flows down from the peripheral edge of the collision plate. The exhaust gas rising in the riser collides with the lower surface of the collision plate having the liquid film thus formed on the lower surface, and comes into contact with the liquid film. Due to this collision, a trace amount of sulfurous acid gas remaining in the exhaust gas is captured by the liquid film and separated and removed from the exhaust gas.

As described above, the exhaust gas rising in the riser 4 is caused to collide with the lower surface of the collision plate having the liquid film formed on the lower surface, so that the sulfur dioxide gas remaining in the exhaust gas and the droplet particles Also, pollutants such as solid fine particles contained in the exhaust gas can be efficiently removed from the exhaust gas, thereby further improving the exhaust gas treatment effect.

In the liquid dispersion mechanisms 8 to 11 shown in FIG. 1, the liquid dispersion mechanism 10 is for spraying droplets onto the lower surface of the collision plate to constantly form a liquid film on the lower surface of the collision plate 7. is there. By disposing the liquid dispersion mechanism 10, it is possible to always form a liquid film having a constant thickness on the lower surface of the collision plate even when the amount of droplet particles in the exhaust gas that has risen from the riser is small. The liquid dispersion mechanisms 9 and 11 are for spraying a liquid into the exhaust gas rising in the riser. By the spray of the liquid by the liquid dispersion mechanisms 9 and 11, the exhaust gas rising in the riser comes into contact with the droplet particles formed by the spray of the liquid, and the pollutants such as sulfurous acid gas contained in the exhaust gas are discharged from the exhaust gas. To be removed. Further, since the droplet particles are accompanied by the exhaust gas and collide with the collision plate, they also serve to form a liquid film on the lower surface of the collision plate. Liquid dispersion mechanism 8
Is for spraying droplet particles into the third chamber c. The droplet particles sprayed in the third chamber c by the liquid dispersion mechanism 8 come into contact with the exhaust gas after colliding with the collision plate in the third chamber c, and have the action of removing pollutants from the exhaust gas. Further, the liquid dispersion mechanisms 9 and 11 can also be installed so as to spray the liquid into the exhaust gas after colliding with the collision plate. Further, the distance between the upper end of the riser and the collision plate varies depending on the flow velocity of the exhaust gas rising in the riser,
500mm is preferable. If it is less than 300 mm, the pressure loss due to the change of the flow path at the time of collision of exhaust gas is large, and it is not economical. If it exceeds 1500 mm, the effect due to the collision becomes extremely small.

According to the present invention, it is essential to dispose a liquid dispersion mechanism for jetting the liquid downward in the middle portion of the riser 4, and all the liquid dispersion mechanisms 8 to 11 and 18 are required. Alternatively, a part can be omitted. Further, the exhaust gas collision plate 7 can be omitted if necessary, but in the case of the present invention, the exhaust gas collision plate 7 rises up the riser 4 and the exhaust gas introduced into the third chamber c has a considerable amount of droplet particles. Therefore, the arrangement of the collision plate is preferable from the viewpoint of separating and removing the droplet particles from the exhaust gas. When liquid is sprayed downward from the liquid dispersion mechanism installed in the riser into the rising exhaust gas in the riser, the droplet particles ejected downwards as a counterflow to the rising exhaust gas. After making a certain distance downward while contacting, the flow path is reversed, and the rising exhaust gas rises in the riser together with the exhaust gas while making contact as a parallel flow. Then, in the portion where the droplet particles advancing as the downward flow are reversed to the upward flow, a strong mixing action works on the droplet particles, coalescence of the droplet particles and division of the droplet particles (particulation).
Occurs, the surface of the droplet particles is renewed, and the droplet particles whose surface reactivity has decreased due to countercurrent contact with the exhaust gas become droplet particles with improved surface reactivity again.

The traveling distance S of the droplet particles in the downward direction (the distance from the liquid dispersion mechanism to the reversal portion of the droplet particles) is determined by the ejection speed of the liquid from the liquid dispersion mechanism and the droplet particles formed by spraying. In relation to the particle size (diameter), the jetting speed thereof is high, and the larger the particle size of the droplet particles is, the longer the traveling distance S is. In the present invention, in terms of the reversal of the droplet particle flow, which is preferable for causing coalescence or division of droplet particles, and the efficiency of trapping pollutants in the exhaust gas by the droplet particles, the traveling distance S is 50 mm or more, preferably 200 to 200
It is preferable to define it in 0 mm, more preferably in the range of 1000 to 2000 mm. Further, it is preferable that the average particle diameter of the droplet particles be fine, but from the viewpoint of easy collection of the droplet particles after jetting by the collision plate, the flow path changing member, or the like, it is 50 μm.
It is better to have m or more. On the other hand, when the droplet particles are collected by the wet electrostatic precipitator, the average particle size may be finer than 50 μm. As the traveling distance S of the droplet particles, for example, in the case of droplet particles having an average particle diameter of 800 μm, the traveling distance S of 1000 mm or more can be obtained by setting the ejection speed to 7 m / sec or more. When the particle size of the droplet particles becomes large, the traveling distance S of the droplet particles becomes long due to the added gravity of the particles, so that the ejection speed of the droplet particles is adjusted according to the particle diameter of the droplet particles. Further, the liquid ejection speed is adjusted according to the gas rising speed in the riser. As described above, the desulfurization efficiency from the exhaust gas is further improved by advancing the droplet particles in the riser as a downward flow for a predetermined distance and then changing the flow path of the droplet particles to the upward flow. be able to.

The rising speed of the exhaust gas in the riser is
Usually, it is 3 to 20 m / sec, but in the present invention, the exhaust gas rising speed in the riser is set so that the droplet particle flow can be reversed from the lower direction to the upper direction at any rising speed in this range. A liquid dispersion mechanism designed to be able to invert even when small is installed. As described above, the rise rate of the exhaust gas in the riser fluctuates greatly. Therefore, in practice, the traveling distance S of the droplet particles varies depending on the rise rate, which causes a change in the desulfurization rate. Therefore, fluctuations in the exhaust gas load (such as the rising speed of the exhaust gas in the riser)
On the other hand, in order to secure stable desulfurization performance, it is preferable to dispose a plurality of liquid dispersion mechanisms in the riser (Fig. 1 shows a flue gas desulfurization device having a two-stage liquid dispersion mechanism). For example, the maximum rising speed of exhaust gas in the riser is 10
At m / sec or less, one-stage liquid dispersion mechanism, at 15 m / sec, 2
It is advisable to dispose a liquid dispersion mechanism of stages, and a liquid dispersion mechanism of 3 stages at 20 m / sec.

The liquid supplied to the liquid dispersion mechanism may be a liquid having the same composition as or a similar composition to the exhaust gas treating liquid, or may be any liquid having reactivity with sulfurous acid gas, It may be any readily available liquid such as water or seawater. In particular, the use of water is preferable because even if the sprayed droplet particles remain in the treated exhaust gas, they do not become dust. As the liquid, for example, Ca (OH) ₂
And CaCO ₃ , Mg (OH) _{2 and} other calcium and magnesium compound solutions and slurries; NaOH, K
Aqueous solution of alkali metal hydroxide such as OH; NaHC
Aqueous solution of alkali metal carbonate such as O ₃ , Na ₂ CO ₃ , KHCO ₃ and K ₂ CO ₃ ; Slurry containing gypsum produced by reaction of exhaust gas and treatment solution, mother liquor after separation of gypsum from this slurry, etc. Can be used. The amount of liquid sprayed into the exhaust gas rising up the riser is usually 0.0 / gas ratio in order to ensure the necessary minimum gas-liquid contact.
5 liter / Nm ³ or more is required, basically gas /
It is preferable that the liquid ratio is large, but practically 0.1 to
The range is 1.5.

As the liquid jetted into the riser 4,
The use of aqueous solutions containing alkali metal hydroxides is preferred.
When an aqueous solution of such a strongly alkaline alkali metal hydroxide is used, the alkali metal hydroxide absorbs CO ₂ contained in the exhaust gas and dissolves as a carbonate in the absorption liquid, and has a pH buffering action. Since the exhaust gas comes into contact with the droplet particles in a high pH condition suitable for absorbing sulfur dioxide gas, the sulfur dioxide gas in the exhaust gas is absorbed efficiently and even until the sulfur dioxide gas concentration in the exhaust gas becomes extremely low. It has the advantage that it can be removed and, in addition, it can be used in small amounts. Further, when using an aqueous solution of an alkali metal carbonate or hydroxide, it is possible to avoid the problem of scale generation on the inner surface of the pipe, which has been observed when using an aqueous solution containing a calcium compound or a slurry solution. There is also an advantage that you can.

When a liquid is supplied to the liquid dispersion mechanism 20 or 20 'in the riser, a predetermined amount of the processing liquid L in the first chamber a is extracted and used as it is or as a mother liquor obtained by filtering or centrifuging it. Can be supplied to the liquid dispersion mechanism.
Further, when the liquid ejected from the liquid dispersion mechanisms 20 and 20 ′ and the liquid dispersion mechanisms 9 to 11 and 18 are used on the surface of the second partition plate 6 which forms the floor surface of the third chamber c, those liquids are used. The liquid ejected from the dispersion mechanism is retained, but in the present invention, this retained liquid can be extracted and circulated and supplied to the liquid dispersion mechanism 20, 20 ′ arranged in the riser or another liquid dispersion mechanism. .

The processing liquid L in the first chamber a and the second partition plate 6
Of the accumulated liquid on the surface of the liquid through the pipes 20, 20
In the case of circulating supply to 0 ′, those liquids are first introduced into the liquid storage tank and temporarily stored therein, and then the liquid dispersion mechanism 20, 20 ′ and / or another liquid dispersion mechanism 8 via the pipe.
It is preferable to supply to 11 to 18 and the like. In this case, part of the liquid flowing in the pipe before or after entering the liquid storage tank is extracted and introduced into the processing liquid in the first chamber a,
It is preferable to supply a replenishing liquid to the liquid storage tank. In this way, when a part of the liquid is withdrawn from the pipe before or after the liquid storage tank and introduced into the processing liquid L in the first chamber a, it is supplied to the liquid dispersion mechanisms 20, 20 ′ and other liquid dispersion mechanisms. The component composition of the liquid to be treated can be always maintained within a predetermined range, and the sulfurous acid gas removal capacity remaining in the liquid can be transferred to the treatment liquid L in the first chamber a, and the sulfurous acid of the treatment liquid L can be transferred. The gas removal capacity can be enhanced.

The shape of the exhaust gas collision plate 7 may be a flat plate shape, but the central portion projects upward from the peripheral end portions so that the liquid film can be easily formed and the sulfurous acid gas in the exhaust gas can be easily separated. The shape, for example, the shape as shown in FIG. Further, with respect to the collision plate, a liquid dispersion mechanism that disperses the liquid in the form of a liquid curtain or a spray below the collision plate can be arranged at the center of the collision plate. FIG. 2 shows an example in which a liquid dispersion mechanism for dispersing the liquid in a liquid curtain shape is arranged on the collision plate. This liquid dispersion mechanism includes a liquid introduction pipe 23 that opens below the center of the collision plate, a short cylinder 24 that surrounds the opening of the liquid introduction pipe, and a liquid dispersion plate 25 that is arranged at the tip opening of the short cylinder. Composed of. The liquid dispersion plate 25 may have a structure that radially disperses the liquid, and may have, for example, the structure shown in FIGS. 3 and 4. Further, the dispersion plate 25 can be connected to a rotary motor and rotated to increase the ejection speed of the dispersed liquid. As a result, the efficiency of gas-liquid contact can be increased.

In the present invention, an exhaust gas flow path changing member may be used instead of the exhaust gas collision plate 7 arranged above the riser 4. The exhaust gas flow path changing member is composed of a hollow structure whose lower end has a gas guide wall located between the surface of the second partition plate 6 and the upper end of the riser 4. In the exhaust gas flow path changing member having such a hollow structure, the exhaust gas that has risen up the riser 4 enters the hollow molded body through the lower end opening thereof, collides with the lower surface thereof, and passes through the flow path through the gas guide wall. And is brought into contact with the liquid (retained liquid) staying on the upper surface of the second partition plate 6 forming the floor surface of the third chamber c. In the contact between the exhaust gas that has become the downward flow and the liquid that remains on the second partition plate in this case, the exhaust gas is introduced into the liquid to form bubbles and rise in the liquid.
It includes the contact made by the downflowing exhaust gas impinging on the liquid surface.

In the exhaust gas flow path changing member, the exhaust gas collision surface may be a flat surface or a curved surface, and the gas guide wall surface may be a flat surface or a curved surface. Notches can be formed. Furthermore, the gas guide wall can be formed continuously or discontinuously around the gas impingement surface. FIG. 5 to FIG. 12 show the arrangement state diagram together with the structural example. In these figures, reference numeral 26 denotes an exhaust gas flow path changing member.

The structure shown in FIG. 5 has a hollow spherical body structure having an opening at the lower end, and a central portion A of the hollow spherical body forms an exhaust gas collision portion, and a curved surface portion B extending downward from the central portion A. Form the gas guide wall. Further, in FIG.
Is a second partition plate, 4 is a riser, C is its upper end, and L ₂ is a liquid. In the exhaust gas flow path changing member shown in FIG. 5, the tip of the gas guide wall can be positioned at the same level as, or slightly below or slightly above, the liquid level of the second absorbing liquid L ₂ .

The one shown in FIG. 6 is a box-shaped body having an opening at the lower end, and its upper plate A forms an exhaust gas collision portion, and a side wall B extending downward from the peripheral edge of the upper plate is a gas guide wall. Form. Further, in FIG. 6, 6 is a second partition plate, 4 is a riser, C is its upper end, and L ₂ is a liquid. In the exhaust gas passage changing member shown in FIG. 6, the tip of the gas guide wall can be located at the same level as the liquid surface of the liquid L ₂ or slightly below or slightly above it.

The structure shown in FIG. 7 is of a hollow structure having a lower end opened. The central portion A forms an exhaust gas collision portion, and the curved surface portion B extending downward from the central portion forms a gas guide wall. To do. This hollow structure has four curved surfaces protruding upward, and its perspective view is shown in FIG. 7 (b).
Further, in FIG. 7, 6 is a second partition plate, 4 is a riser,
C indicates the upper end and L ₂ indicates a liquid. In the exhaust gas flow path changing member shown in FIG. 7, the tip of the gas guide wall is the liquid L ₂
It can be located at the same level as, or slightly below or slightly above.

The one shown in FIG. 8 is a hollow spherical body having a lower end opened, and a central portion A forms an exhaust gas collision portion, and a curved surface portion B extending downward from the central portion forms a gas guide wall. To do. In this hollow spherical body, the tip of the gas guide wall is bent inward, so that the exhaust gas introduced into the hollow spherical body forms a vortex and the absorption liquid is wound inside the hollow spherical body. Shows the effect of raising. The action of winding up the absorbing liquid can be obtained by bending the tip end of the gas guide wall inward in the same manner as shown in FIGS. 5 to 7. In FIG. 8, 6 is a second partition plate, 4 is a riser, C is its upper end, L
₂ indicates a liquid. In the exhaust gas flow path changing member shown in FIG. 8, the tip of the gas guide wall can be positioned at the same level as the liquid surface of the liquid L ₂ or slightly below or slightly above it.

The one shown in FIG. 9 is of a hollow structure having a lower end opening and a central portion formed into a curved surface, and the central portion A forms an exhaust gas collision portion, and extends downward from the central portion. The curved surface portion B forms a gas guide wall. In this hollow structure, the tip of the gas guide wall is bent outward, and therefore, there is an advantage that the pressure loss when exhaust gas is blown out from the lower end opening of the central structure is small. Further, in FIG. 9, 6 is a second partition plate, 4 is a riser, C is its upper end, and L ₂ is a liquid. In the exhaust gas flow path changing member shown in FIG. 9, the tip of the gas guide wall can be positioned at the same level as or slightly below or slightly above the liquid level of the liquid L ₂ .

The structure shown in FIG. 10 has a hollow spherical body structure having an opening at the lower end, and the central portion A forms the exhaust gas collision portion, and the curved surface portion B extending downward from the central portion forms the gas guide wall. Form. The hollow spherical body has a large number of circular gas ejection holes P at the tip of the gas guide wall, and the exhaust gas is ejected into the liquid L ₂ from the gas ejection holes. Further, in FIG. 10, 3 is a second partition plate, 4 is a riser, C is its upper end, and L ₂ is a liquid. In the exhaust gas flow path changing member shown in FIG. 10, the tip of the gas guide wall and the gas ejection hole P are located in the liquid L ₂ .

Similar to the one shown in FIG. 10, the one shown in FIG. 11 has a hollow spherical body structure of which the lower end is opened, and the central portion A forms an exhaust gas collision portion, and the lower portion from the central portion. The curved surface portion B extending to form a gas guide wall. This hollow spherical body has a large number of cutouts Q at the tip of the gas guide wall, and the exhaust gas flows from the cutouts Q to the liquid L ₂
Gush into the inside. Further, in FIG. 11, 6 is a second partition plate, 4 is a riser, C is its upper end, and L ₂ is a liquid.
In the exhaust gas flow path changing member shown in FIG. 11, the tip of the gas guide wall and the notch Q thereof are located in the liquid L ₂ .

The one shown in FIG. 12 is a box-shaped body having an opening at the lower end, which is arranged on a riser having a rectangular cross section. Side walls B ₁ and B ₂ extending downward from the periphery of the plate form the gas guide wall. In this box-shaped body, the side wall B ₂ having a smaller surface area can be omitted if necessary. In FIG. 12, 3 is a second partition plate, 4 is a riser,
C indicates the upper end and L ₂ indicates a liquid. In the exhaust gas flow path changing member shown in FIG. 12, the tip of the gas guide wall is the liquid L.
It can be located at the same level as or slightly below or slightly above the liquid level of ₂ . Further, in the exhaust gas flow path changing member shown in FIG. 12, holes or notches for ejecting gas can be formed at the tips of the side walls B ₁ and B ₂ as shown in FIGS. 10 and 11. . In this case, the tips of the side walls B ₁ and B ₂ and the holes and cutouts for ejecting the gas are located in the liquid L ₂ .

The exhaust gas flow path changing member 26 receives the exhaust gas rising from the riser 4 on its lower surface, changes it into a downward flow by its gas guide wall, and retains the liquid L ₂ retained on the second partition plate.
It has a function of contacting with. By the action of the exhaust gas flow path changing member 26, the sulfurous acid gas contained in the exhaust gas is absorbed and removed in the liquid by the contact between the exhaust gas whose flow path has been changed and the liquid L ₂ .

For the exhaust gas flow path changing member 26, as in the case of the exhaust gas collision plate, a liquid dispersion for dispersing the liquid in the form of a liquid curtain or a spray below the exhaust gas flow path changing member in the central lower part thereof. A mechanism can be provided.

[0031]

EXAMPLES The present invention will be described in more detail by way of examples. It goes without saying that the device of the present invention is not limited to that shown in the embodiments. For example, the gas discharge pipe 16 is a third
It can also be provided so that the exhaust gas is extracted horizontally from the chamber c.

Example 1 Exhaust gas was treated using the flue gas desulfurization apparatus of the present invention having the structure shown in FIG. However, the liquid dispersion mechanisms 8 to 11 and 18 are omitted. Further, for comparison, the liquid dispersion mechanisms 20, 2
Exhaust gas was treated using an apparatus having the same structure except that the jet of liquid from 0'was directed upward. The exhaust gas treatment conditions in this case are as follows.

(1) Properties of exhaust gas supplied SO ₂ concentration: 720 ppm Gas amount: 10,000 Nm ³ / h Temperature: 90 ° C. (2) Properties of exhaust gas at riser inlet SO ₂ concentration: 57 ppm Temperature: 46 ° C. (3 ) gas velocity rises in the riser: 12m / sec (4) operating conditions feed liquid distribution mechanism 20, 20 is disposed in the riser ': a NaHCO _3, aqueous solution of 0.015 mol / l including pH7.5 Average particle diameter of droplet particles ejected from the dispersion mechanism: 500 μm Liquid ejection velocity: 6 m / sec Distance of droplet particles traveling downward S: 600 mm (5) Exhaust gas treatment liquid Slurry containing 0.5% by weight of CaCO ₃ Liquid, temperature 46 ℃

The exhaust gas was treated under the above conditions, the properties of the exhaust gas after passing through the mist eliminator 17 of the gas discharge pipe were examined, and the performance of the device of the present invention and the conventionally known device (comparative device) was compared. . Table 1 shows the results.

[0035]

[Table 1]

Example 2 In Example 1, the feed liquid was changed to the exhaust gas treatment liquid L by CaCO.
_The operation was performed under the same conditions except that ₃ was added to form a slurry having a pH of 6.5. As a result, the SO ₂ concentration in the exhaust gas after passing through the mist eliminator 17 was 18 ppm.

[0037]

According to the present invention, a high desulfurization rate, which is difficult to achieve by the conventional method, can be obtained with low power consumption without requiring an increase in the treatment cost, and its industrial significance is great. .

[Brief description of drawings]

FIG. 1 shows a schematic diagram of the device of the present invention.

FIG. 2 is a schematic diagram of a collision plate provided with a liquid dispersion mechanism.

FIG. 3 shows a perspective view of one example of a dispersion plate.

FIG. 4 is a perspective view of another example of the dispersion plate.

5A and 5B are a structural explanatory view and an arrangement state diagram of one example of an exhaust gas flow path changing member.

FIG. 6 is a structural explanatory view and an arrangement state diagram of another example of the exhaust gas flow path changing member.

FIG. 7 is a structural explanatory view and an arrangement state diagram thereof regarding still another example of the exhaust gas flow path changing member.

FIG. 8 is a structural explanatory view and an arrangement state diagram thereof regarding still another example of the exhaust gas flow path changing member.

9A and 9B are a structural explanatory view, an arrangement state diagram and an arrangement state diagram of still another example of the exhaust gas flow path changing member.

FIG. 10 is a structural explanatory view and an arrangement state diagram thereof regarding still another example of the exhaust gas flow path changing member.

FIG. 11 is a structural explanatory view and a layout state diagram thereof regarding still another example of the exhaust gas flow path changing member.

FIG. 12 is an explanatory diagram of an exhaust gas flow path changing member provided with a liquid dispersion mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed tank 2 Exhaust gas supply pipe 3 Gas introduction pipe 4 Riser 5 1st partition plate 6 2nd partition plate 7 Exhaust gas collision plate 8-11, 18, 20 Liquid dispersion mechanism 12-15, 19, 21, 23 Liquid supply pipe 16 Gas exhaust pipe 17 Mist eliminator 25 Liquid dispersion plate 26 Exhaust gas flow path changing member

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location B01D 53/18 E 53/34 ZAB B01D 53/34 125 C (72) Inventor Iwasaki Mamoru 2-12-1, Tsurumi Chuo, Tsurumi-ku, Yokohama-shi, Kanagawa Chiyoda Kakoh Construction Co., Ltd. (72) Inventor Eiji Awai 2-1-1, Tsurumi Chuo, Tsurumi-ku, Yokohama-shi, Kanagawa Chiyoda Kakoh Construction (72) Inventor Dai Takeda 2-12-1, Tsurumi-Chuo, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Chiyoda Kakoh Construction Co., Ltd.

Claims (5)

[Claims] 1. A desulfurization treatment method for exhaust gas, which comprises a step of collecting the treated exhaust gas after contacting the treatment liquid with a riser and transferring it to an upper space at high speed, wherein a liquid dispersion mechanism is provided in the riser. When ejecting liquid as droplet particles downward into the exhaust gas rising from the liquid dispersion mechanism, the droplet particles are ejected so as to flow downward and then flow upward to change the flow path. Exhaust gas desulfurization method. 2. An exhaust gas collision plate or an exhaust gas flow path changing member is disposed above an outlet of the riser, and exhaust gas containing droplet particles that has risen in the riser is made to collide with a lower surface of the collision plate or the exhaust gas flow path changing member. The method of claim 1. 3. The method according to claim 1, wherein the liquid is an aqueous solution of an alkali metal hydroxide. 4. An exhaust gas desulfurization apparatus having a riser for collecting the treated exhaust gas after contacting it with a treatment liquid and transferring it to the upper space at high speed. Droplet particles ejected into the riser where the exhaust gas rises. An exhaust gas desulfurization treatment apparatus, characterized in that a liquid dispersion mechanism for ejecting a liquid downward is arranged so as to change the flow path upward after progressing downward. 5. The apparatus according to claim 4, wherein an exhaust gas collision plate or an exhaust gas flow path changing member is arranged above the outlet of the riser.