JPH10192647A - Wet type flue gas desulfurization equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high desulfurizing performance even when a boiler load, a sulfur oxide concentration in flue gas, etc., are varied by a method wherein an absorption liquid dispersing pipe is arranged in a direction whose a longitudinal direction is not horizontal, and a liquid reserving part feeding the absorption liquid is provided above the dispersing pipe. SOLUTION: A flue gas A discharged from a boiler is introduced into a desfurizing column body 1. When absorbing liquid is spray from a spray nozzle 4 and gas is brought into contact with the liquid, the absorbing liquid absorbs SO2 in the flue gas A to generate sulfurous acid. Then, the drop of the absorbing liquid drops onto a liquid reserving part 22, and the sulfurous acid is oxidized with air from an air blowing device 8 to form sulfuric acid. It is conducted to a limestone layer 19 from the dispersing pipe 17 to generate gypsum C by neutralization reaction of the sulfuric acid with the limestone. Then, through the absorbing liquid in which pH is recovered is sent to a spray nozzle 4 from an absorbing liquid extraction pipe 10, a portion thereof is sent to a dehydrator 13, and the gypsum C is recovered. Further, the limestone D is red into a circulating tank 6 from a limestone feed pipe 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet flue gas desulfurization apparatus, and more particularly, to a high desulfurization performance, which can reduce the power of crushing a solid desulfurizing agent such as limestone and economically discharge it from a boiler or other combustion apparatus. TECHNICAL FIELD The present invention relates to a wet flue gas desulfurization device for removing sulfur oxides from exhaust gas to be discharged.

[0002]

2. Description of the Related Art Sulfur oxides, particularly sulfur dioxide (SO ₂ ), in flue gas generated by the combustion of fossil fuels in thermal power plants and the like are one of the main causes of global environmental problems such as air pollution and acid rain. It is one of the causes. For this reason, SO
Research on flue gas desulfurization method to remove ₂ and development of desulfurization equipment are extremely important issues.

Various processes have been proposed as the desulfurization method, but the wet method is dominant. This wet method includes a soda method using a soda compound as an absorbent,
There are a calcium method using a calcium compound and a magnesium method using a magnesium compound. this house,
The soda method has excellent reactivity between the absorbent and SO ₂ , but the soda used is very expensive. For this reason,
In a flue gas desulfurization apparatus such as a large boiler for power generation, a method using a relatively inexpensive calcium compound such as calcium carbonate is most often employed.

[0004] Desulfurization systems using this calcium compound as an absorbing solution are roughly classified into three types, a spray system, a wet wall system and a bubbling system, depending on the gas-liquid contact method. Although each method has its own characteristics, spray methods that have a good track record and high reliability are widely used worldwide. As this spray type desulfurization system,
BACKGROUND ART Conventionally, a cooling tower for cooling and removing dust from an exhaust gas, a desulfurization tower for spraying an absorbing liquid to react with SO ₂ in the exhaust gas, and an oxidation tower for oxidizing calcium sulfite generated in the desulfurization tower have been constituted. However, in recent years, the development of a single-column desulfurization tower (oxidation method in a tank) in which the desulfurization tower has cooling and oxidation functions has been advanced, and recently, the single-column desulfurization system is becoming the mainstream of the spray method. .

FIG. 8 shows an example of a conventional single-column type desulfurization apparatus using a spray method. The single-column type desulfurization tower is mainly composed of a tower body 1, an inlet duct 2, an outlet duct 3, a spray nozzle 4, an absorption liquid pump 5, a circulation tank 6, a stirrer 7, an air blowing device 8, a mist eliminator 9, and an absorption liquid. It is composed of an extraction pipe 10, a gypsum extraction pipe 11, a limestone supply pipe 12, a dehydrator 13, and the like. A plurality of spray nozzles 4 are provided in the horizontal direction and a plurality of stages are provided in the height direction. Further, the stirrer 7 and the air blowing device 8 are installed in the circulation tank 6 at the lower part of the desulfurization tower where the absorbing liquid stays, and the mist eliminator 9 is installed in the uppermost part in the desulfurization tower or in the outlet duct 3. Exhaust gas A discharged from a boiler (not shown) is introduced into the desulfurization tower main body 1 from an inlet duct 2 and discharged from an outlet duct 3. During this time, the absorption liquid sent from the absorption liquid pump 5 is sprayed from the plurality of spray nozzles 4 through the absorption liquid extraction pipe 10 to the desulfurization tower, and the absorption liquid and the exhaust gas A are brought into gas-liquid contact. At this time, the absorbing liquid selectively absorbs SO ₂ in the exhaust gas A and generates calcium sulfite. The absorption liquid that has generated calcium sulfite stays in the circulation tank 6, and while being stirred by the stirrer 7, the calcium sulfite in the absorption liquid is oxidized by the air B supplied from the air blowing device 8 to produce gypsum C. The pH of the circulating absorbent is measured by the pH meter 21.

A desulfurizing agent such as limestone D is supplied from a limestone supply pipe 12.
It is added to the absorption liquid in the circulation tank 6. Part of the absorption liquid in the circulation tank 6 where limestone D and gypsum C coexist,
The absorbent pump 5 sends the absorbent to the spray nozzle 4 again from the absorbent extraction pipe 10, and a part of the gypsum extraction pipe 11.
The gypsum C is collected by being sent to the dehydrator 13. Also,
Of the absorbing liquid atomized by the spray nozzle 4 and atomized, those having a small droplet diameter are accompanied by the exhaust gas A, but are collected by the mist eliminator 9 provided at the upper part of the desulfurization tower.

However, the prior art shown in FIG. 8 uses finely ground limestone, and has the following problems. (I) The absorbent contains not only calcium carbonate (limestone) that absorbs SO ₂ but also a large amount of gypsum that does not contribute to the absorption. To improve desulfurization performance, the proportion of limestone in the absorbent is reduced. If increased, the quality of the gypsum deteriorates and the gypsum becomes unavailable. (Ii) There is much power for grinding limestone.

The present inventors have tried to solve these problems and have used a limestone having an average particle size of 0.5 mm or more, and separated limestone and gypsum, thereby achieving high desulfurization performance without deteriorating the quality of the gypsum. (For example, Japanese Patent Application No. 7-40316). FIG. 5 shows an example of an apparatus flow of this process. As in the prior art desulfurization tower shown in FIG. 8, the tower body 1, the inlet duct 2, the outlet duct 3,
Spray nozzle 4, absorbent pump 5, circulation tank 6, stirrer 7, air blowing device 8, and mist eliminator 9
In the embodiment according to the present invention, the fallen absorbent is further collected to form a flow that flows from the bottom to the top of the layer of limestone particles at the lower portion of the circulation tank 6, and the limestone particles flow in the absorbent. Liquid collecting plate 14, introduction pipe 1
5, a branch pipe 16 (see FIG. 6B) and a dispersion pipe 17.

Exhaust gas A discharged from the boiler is introduced into the desulfurization tower main body 1 through the inlet duct 2 and discharged through the outlet duct 3. During this time, the absorbing liquid sent from the pump 5 is sprayed from the plurality of spray nozzles 4 into the desulfurization tower, and gas-liquid contact between the absorbing liquid and the exhaust gas A is performed. At this time, the absorbing liquid selectively absorbs SO ₂ in the exhaust gas A and generates sulfurous acid. The absorbing droplets that have generated sulfurous acid fall on the liquid collecting plate 14 provided on the circulation tank 6. The absorbing liquid on the collecting plate 14 is collected and led to the bottom of the circulation tank 6 through the introduction pipe 15. Sulfurous acid is oxidized into sulfuric acid by the oxidizing air blown from the air blowing device 8 on the way. At the bottom of the introduction pipe 15, a dispersion pipe 17 for uniformly raising the absorption liquid.
Is attached. FIG. 6 shows an example of the structure.

FIG. 6 is a sectional view of the tank side (FIG. 6 (a)) and a sectional view of the tank bottom (FIG. 6 (b)). Is adopted so as to rise uniformly. That is, the dispersion pipe 17 is uniformly arranged at the bottom of the circulation tank 6,
The absorption liquid guided from the introduction pipe 15 enters the branch pipe 16 and is further guided to the dispersion pipe 17. The dispersion pipe 17 is provided with a plurality of dispersion holes 18 through which the absorbing liquid and air are uniformly and violently ejected to form an upward flow. Gypsum is generated in the flowing limestone layer 19 by the reaction between sulfuric acid and limestone.

The absorbing solution neutralized in this way and having recovered the pH is sent to the spray nozzle 4 again through the absorbing solution extracting pipe 10 from the outlet 20 at the upper part of the circulation tank 6, and
Selectively absorbs SO _2. Part of the absorbing solution is dehydrated 13
And the gypsum C is collected. The limestone D is supplied from the limestone supply pipe 12 into the circulation tank 6.

This process is characterized in that limestone pulverizing equipment and power are not required, and the quality of the produced gypsum is high. However, in order to uniformly eject the absorbing liquid from any of the dispersion holes 18, the branch pipe 16 and the dispersion pipe 1 are required.
It is necessary to install a resistor inside 7. Installing a resistor increases the pressure loss in the piping, which not only requires extra pump power, but also reduces the amount of circulating absorbent in the wet flue gas desulfurization unit due to changes in boiler load and sulfur oxide concentration in exhaust gas. When changed, the liquid flow rate in the branch pipe 16 and the dispersion pipe 17 becomes non-uniform, and the amount of the absorbent ejected from the dispersion holes 18 becomes non-uniform, so that the pH of the neutralized absorbent becomes a predetermined value. There was a problem that it was lower.

[0013]

The above-mentioned invention requires an extra pump power, and when the boiler load or the sulfur oxide concentration in the exhaust gas changes, the absorption liquid after neutralization is changed. There was a problem that the pH was lower than a predetermined value. An object of the present invention is to solve the above problems and propose a desulfurization apparatus that is economical and can achieve high desulfurization performance even when the boiler load or the sulfur oxide concentration in exhaust gas changes.

[0014]

The object of the present invention is achieved by the following constitution. That is, a wet flue gas desulfurization device that treats sulfur oxides in exhaust gas by bringing exhaust gas discharged from a combustion device such as a boiler into contact with an absorbent, wherein the pH of the absorbent is reduced due to the absorption of the sulfur oxides. A structure in which a solid desulfurizing agent is selectively retained at a site where neutralization is performed, and a solid product or water generated from sulfur oxide is selectively discharged from the neutralizing site. In a wet flue gas desulfurization apparatus having a function of flowing particles in an absorbent, an absorbent dispersion pipe having an open end for sending to a site for neutralizing the absorbent is arranged in a direction in which the longitudinal direction is not horizontal, and the dispersion is performed. This is a wet type flue gas desulfurization apparatus provided with a liquid storage section at the upper part of a pipe for supplying an absorption liquid to the dispersion pipe.

The solid desulfurizing agent used in the present invention (eg, limestone)
Has a weight average particle size (hereinafter, referred to as an average particle size) of 0.1.
It is preferably at least 5 mm, and the average particle size is 0.5 m
If it is less than m, separation from a solid product such as gypsum as a desulfurizing agent becomes difficult, and the solid desulfurizing agent such as limestone after pulverization may be pulverized in a process of being conveyed to a flue gas desulfurization device. More preferably, the average particle size of the solid desulfurizing agent is 1.0 mm
That is all. When the average particle size of the solid desulfurizing agent exceeds 10 mm, the reaction activity of neutralizing the absorbing solution that has absorbed SO ₂ in the exhaust gas decreases, and the solid desulfurizing agent connected to the neutralizing section of the flue gas desulfurization device The supply pipe may be worn. Therefore, the solid desulfurizing agent of the present invention preferably has an average particle size of 0.5 mm to 10 mm. In the present invention, the solid desulfurizing agent has a particle size of 0.5
Particles having a particle size of less than 1 mm may be included, and the average particle size is only a rough guide and does not mean an exact particle size.

Limestone is a typical example of the solid desulfurizing agent of the present invention. Limestone in the present invention refers to a sedimentary rock containing calcium carbonate as a main component, and those containing magnesium carbonate are also used in the present invention. It is assumed that. Therefore, dolomite (main component CaCO ₃ · MgCO ₃ )
Are also included in the limestone of the present invention. In addition, for example, since limestone contains impurities, the impurities affect the desulfurization reactivity, and such impurities can be pulverized to expose highly reactive CaCO ₃ on the solid surface. desirable. However, even if the desulfurization reactivity is high, the fine particulate solid desulfurizing agent is mixed into a solid product such as gypsum, so that the fine particles need to be separated and removed. If the particle size is too large, the solid desulfurizing agent supply section may be damaged. Therefore, it is preferable to provide a filter or a cyclone in the solid desulfurizing agent supply section to classify the solid desulfurizing agent.

[0017]

The main reactions in the desulfurizer based on the method of the present invention are shown below. Here, limestone (CaCO 2) is used as the solid desulfurizing agent.
An example using ( ₃ ) will be described. Absorbent (main component:
(Water) absorbs SO ₂ in the exhaust gas to produce H ₂ SO ₂ , which is oxidized by air to H ₂ SO ₄ (dilute sulfuric acid).
H ₂ SO ₄ is the limestone is neutralized by (CaCO ₃₎ gypsum _{(CaSO 4 · 2H 2 O)} . (Absorption _{reaction) H 2 O + SO 2 =} H 2 SO 3 ( oxidation _{reaction) H 2 SO 3 + 1 /} 2O 2 = H 2 SO 4 ( neutralization _{reaction) H 2 SO 4 + CaCO 3} + H 2 O = CaSO
₄ · 2H ₂ O + CO ₂

As shown in FIG. 6, an example of the structure of H ₂ SO
_{4 The} absorption liquid containing (dilute sulfuric acid)
8, the limestone flows upward while fluidizing the limestone, and the neutralization reaction occurs to increase the pH of the absorbing solution. However, simply disposing a plurality of dispersion holes 18 in one dispersion pipe 17 does not cause the liquid to be uniformly ejected from the dispersion holes 18. In order to uniformly eject the absorbing liquid, the dispersion pipe 17 must be made thinner toward the tip as shown in FIG. This is apparent from the Bernoulli equation shown below that if p (pressure) and z (height from the reference water surface) are constant, v (flow velocity) must also be constant. p / γ + v ² / 2g + z = H (constant) where γ: specific gravity of fluid g: gravitational acceleration

For this reason, extra pump power is required to uniformly eject the liquid from the dispersion holes 18. Also,
If the boiler load or the sulfur oxide concentration in the exhaust gas changes to change the circulating amount of the absorbing liquid, the flow rate of the liquid ejected from the dispersion holes 18 tends to be uneven. When the flow rate of the liquid ejected from the dispersion holes 18 becomes non-uniform, a certain portion of the limestone layer does not flow, so that the pH of the entire absorbent after neutralization is lower than that when the liquid is ejected uniformly from the dispersion holes 18.

On the other hand, in the neutralization tank of the present invention shown in the embodiment of FIG. 1 and FIG. 2, a dispersion hole 18 is provided at the tip of a dispersion tube 17 whose longitudinal direction is installed substantially vertically, and Since the liquid storage part 22 connected to the pipe 17 is provided at the upper part of the pipe 17, the pressure applied to the dispersion hole 18 is determined by the difference between the liquid level of the neutralization tank and the liquid level of the liquid storage part 22, and the pressure is , The dispersion holes 18 are equal. Therefore, the dispersion tube 17 of the present invention does not need to be provided with a throttle unlike the dispersion tube 17 shown in FIG. 7, so that an extra pump power is not required and the dispersion can be performed by making the inside diameters of the dispersion tubes 17 equal. Hole 18
PH after neutralization because the flow rate of liquid discharged from
(Desulfurization performance) is increased.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the following examples, but is not limited to the following examples. Embodiment 1 An embodiment according to the present invention is shown in FIG. The desulfurization tower according to the present invention shown in FIG. 1 has a tower main body 1, an inlet duct 2, an outlet duct 3, a spray nozzle 4, an absorbing liquid, similarly to the desulfurization tower based on the invention method of the prior application by the present inventors shown in FIG. It is composed of a pump 5, a circulation tank 6, a stirrer 7, an air blowing device 8, a mist eliminator 9, and the like. In this embodiment, a limestone layer 19 is further provided in the circulation tank 6, and the limestone layer 19 is provided. Is disposed in such a manner as to penetrate the liquid in the vertical direction, and a liquid storage part 22 is provided on the upper part thereof. The pH of the circulating absorbent is measured by the pH meter 21.

Exhaust gas A discharged from the boiler is introduced into the desulfurization tower main body 1 from the inlet duct 2 and discharged from the outlet duct 3. During this time, the absorbing liquid sent from the pump 5 is sprayed from the plurality of spray nozzles 4 into the desulfurization tower, and gas-liquid contact between the absorbing liquid and the exhaust gas A is performed. At this time, the absorbing liquid selectively absorbs SO ₂ in the exhaust gas A and generates sulfurous acid. The absorbing droplets that have generated sulfurous acid fall on the liquid storage part 22 installed on the circulation tank 6, and the sulfurous acid is oxidized by the oxidizing air blown from the air blowing device 8 to become sulfuric acid. The absorption liquid containing sulfuric acid in the liquid storage section 22 is guided to the bottom of the limestone layer 19 through the dispersion pipe 17.

A dispersion hole 18 is formed at the tip of the dispersion pipe 17, and the absorbing liquid and air are uniformly and vigorously jetted from the dispersion hole 18 to form an upward flow. Gypsum is generated in the flowing limestone layer 19 by the reaction between sulfuric acid and limestone.

The neutralized absorption liquid whose pH has been restored in this way is sent from the upper outlet 20 of the circulation tank 6 to the spray nozzle 4 again through the absorption liquid extraction pipe 10 and the SO ₂
Is selectively absorbed. Part of the absorbing liquid is sent to the dehydrator 13, and the gypsum C is collected. The limestone D is supplied from the limestone supply pipe 12 into the circulation tank 6.

FIG. 2 is an enlarged view of the neutralizing section. FIG.
FIG. 2A is an enlarged cross-sectional view as viewed from the side, and FIG. 2B is a view taken along the line XX of FIG. 2A. In the flowing limestone layer 19, gypsum is generated by the reaction between sulfuric acid and limestone. However, since gypsum particles are less than limestone particles, only the gypsum particles or water are used to ascend and the outlet 2 at the top of the circulation tank 6 is raised.
From 0, the limestone is discharged to the outside of the circulation tank 6, and the limestone selectively stays in the circulation tank 6.

The average diameter is 1 mm by the apparatus according to this embodiment.
A limestone was used for a desulfurization test. However, the SO ₂ concentration in the exhaust gas A at the inlet of the desulfurization tower is 1000 ppm.
The curve (a) in FIG. 3 shows the relationship between L / G (the ratio between the absorbing solution and the exhaust gas) and the desulfurization rate in this example.

Comparative Example 1 The desulfurization performance was examined using the apparatus shown in FIG. 5 under the same conditions as in Example 1. The result is shown in a curve (b) of FIG. Compared with Example 1, the decrease in the desulfurization rate when L / G decreased was large. This is presumably because the flow rate of the absorbing liquid ejected from the dispersion holes 18 becomes non-uniform when L / G (the liquid amount is constant because the gas amount is constant).

In the first embodiment, the limestone is selectively retained inside the neutralization device by utilizing the difference in the sedimentation speed due to the difference in the particle diameter between limestone and gypsum. However, other methods, such as sieving and inertia force, are used. It is also possible to separate limestone and gypsum by a method using the difference.

The first embodiment is directed to a desulfurization tower having a structure in which exhaust gas is introduced from the lower part of the desulfurization tower and discharged from the upper part, and in which the absorbent is sprayed into the exhaust gas by spraying. Is effective irrespective of the flow direction of the exhaust gas or the contact system between the exhaust gas and the absorbing liquid (such as a wet wall type absorption device).

Embodiment 2 In the above-mentioned embodiment 1, the apparatus structure has a neutralization section installed inside the desulfurization tower. As shown in FIG. 4, a neutralization tank (circulation tank 6-2) is provided separately from the tower body. Installed, circulation tank 6-1
Can also be connected with the connecting pipe 24.

The desulfurization tower of this embodiment shown in FIG.
It is composed of an inlet duct 2, an outlet duct 3, a spray nozzle 4, an absorbent pump 5, a circulation tank 6-1, a stirrer 7, an air blowing device 8, a mist eliminator 9, and the like.
In the present embodiment, the circulation tank 6 is formed by a circulation tank 6-1 provided at a lower portion of the tower main body 1 and the circulation tank 6-1.
Circulation tank 6-2 with limestone layer 19 connected by 4
Consists of

A limestone layer 19 is provided in the circulation tank 6-2, and a dispersion pipe 17 for absorbing liquid is disposed so as to penetrate the limestone layer 19 in the vertical direction. The solution is neutralized. Further circulation tank 6
The liquid storage part 22 is provided in the upper part of -2. Dispersion tube 1
The absorption liquid containing sulfuric acid in the liquid storage unit 22 is dispersed by the dispersion tube 1.
It is led through 7 to the bottom of the limestone layer 19.

A dispersion hole 18 (see FIG. 2) is formed at the tip of the dispersion pipe 17, and the absorbing liquid and air are jetted uniformly and vigorously from the dispersion hole 18 to form an upward flow. Gypsum is generated in the flowing limestone layer 19 by the reaction between sulfuric acid and limestone. The absorption liquid pump 5 is a circulation tank 6
-2 is connected via an absorption liquid extraction pipe 10
The limestone D is supplied from the limestone supply pipe 12 to the circulation tank 6-2.
Supplied within.

The absorbent which has been neutralized in the circulation tank 6-2 and has recovered its pH is sent from the upper outlet 20 of the circulation tank 6 to the spray nozzle 4 again through the absorbent extraction pipe 10 to remove SO ₂ . Selectively absorb. Part of the absorbing liquid is sent to the dehydrator 13, and the gypsum C is collected.

The procedure for treating the exhaust gas A discharged from the boiler in the desulfurization tower of this embodiment is the same as that of the first embodiment, but the circulation tank 6-2 is installed separately from the tower main body 1. Repair and maintenance are easy.

[0036]

According to the present invention, even when the circulation amount of the absorbent changes, the decrease in desulfurization performance is small, and high desulfurization performance can be obtained with less pump power.

[Brief description of the drawings]

FIG. 1 is a one-column wet-type flue gas desulfurization column of an embodiment according to the present invention.

FIG. 2 is a detailed view of a neutralization section of the single-column wet flue gas desulfurization tower of FIG.

FIG. 3 shows experimental data relating to desulfurization methods of Example 1 of the present invention and Comparative Example 1.

FIG. 4 is a one-column wet flue gas desulfurization tower according to another embodiment of the present invention.

FIG. 5 is a conventional single-column wet-type flue gas desulfurization tower.

FIG. 6 is a structural view of a portion for neutralizing an absorbing liquid and a structural view of an absorbing liquid dispersion pipe in a conventional technique.

FIG. 7 is a structural view of a portion for neutralizing an absorbing liquid and a structural view of an absorbing liquid dispersion pipe in the related art.

FIG. 8 shows a single-column wet-type flue gas desulfurization tower according to the prior art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Tower main body 2 Inlet duct 3 Outlet duct 4 Spray nozzle 5 Absorbent pump 6 Circulation tank 7 Stirrer 8 Air blowing device 9 Mist eliminator 10 Absorbent extraction pipe 12 Limestone supply pipe 13 Dehydrator 17 Dispersion pipe 18 Dispersion hole 19 Limestone layer 20 Circulation tank upper outlet 22 Liquid reservoir

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shigeru Nozawa 6-9 Takaracho, Kure-shi, Hiroshima Babcock-Hitachi Kure Factory

Claims (3)

[Claims] 1. A wet flue gas desulfurization unit for treating sulfur oxides in exhaust gas by bringing exhaust gas discharged from a combustion device such as a boiler into contact with an absorbent, wherein the pH is lowered by the absorption of the sulfur oxides. The structure in which the solid desulfurizing agent is selectively retained at the site where the absorbed liquid is neutralized, and the solid product or water generated from the sulfur oxide is selectively discharged from the site where the neutralization is performed. In a wet flue gas desulfurization device having a function of flowing solid desulfurization agent particles in an absorption liquid, an absorption liquid dispersion pipe having an open end for sending to a site for neutralizing the absorption liquid is arranged in a direction in which the longitudinal direction is not horizontal. And a liquid storage unit for supplying an absorbing liquid to the dispersion tube above the dispersion tube. 2. A dispersing tube for sending an absorbing solution to a site for neutralizing the absorbing solution,
2. The wet flue gas desulfurization apparatus according to claim 1, wherein the apparatus has the same diameter in the longitudinal direction. 3. The wet flue gas desulfurization apparatus according to claim 1, wherein an average diameter of the solid desulfurization agent is 0.5 mm or more.