JPH0686910A - Wet-type flue gas desulfurization - Google Patents

Abstract

PURPOSE:To keep an ordinary rate of desulfurization and to reduce remarkably installation cost and operation cost by a method wherein gypsum formed in the reaction process is retained for a specified time in a reactor wherein the gypsum concn. is kept within a specified wt.% and then, the gypsum is separated by sedimentation by gravity in a separation process. CONSTITUTION:A gypsum slurry is pumped up from the bottom of a reactor 12 by means of a gypsum slurry pump 14 and is transferred into a gravity sedimentation tank 18 through a gypsum slurry pipe 16. In the gravity sedimentation tank 18, gypsum crystalline particles are of themselves settled by gravity and deposited on the bottom and the supernatant is drawn through a supernatant extracting pipe 20. In this case, in a reactor 12 wherein the gypsum concn. is kept within a range of 10-30wt.%, the gypsum formed in the reaction process is retained for 10-30 hours to grow largely the crystalline particles of the gypsum. It is possible thereby to perform sedimentation separation of the gypsum which does not need any machine but is done by gravity in a gravity sedimentation tank 18 in a separation process of the gypsum from the gypsum slurry and to make a waste water treating apparatus unnecessary by reusing the supernatant.

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 method using a calcium-containing compound as a desulfurizing agent, a so-called wet calcium-containing compound-gypsum flue gas desulfurization method, and more specifically, equipment costs and operating costs. It relates to a wet calcium-containing compound-gypsum flue gas desulfurization method which is improved so as to be significantly reduced.

[0002]

2. Description of the Related Art A wet calcium-containing compound-gypsum flue gas desulfurization method involves contacting flue gas containing sulfurous acid gas with an aqueous solution for dissolving or suspending a calcium-containing compound in the presence of oxygen in a reactor. A flue gas desulfurization method including a reaction step of fixing sulfurous acid gas as gypsum, a step of extracting gypsum produced in the reaction step as a gypsum slurry from a reactor, and further separating gypsum from the gypsum slurry.

[0003]

The conventional wet flue gas desulfurization method uses a gypsum obtained as a reaction product as an industrial raw material, and a mechanical separation means such as a centrifugal separator is used in the separation step. Since the gypsum is separated, the equipment cost and the operating cost increase, which is one of the causes of the increase in the cost required for flue gas desulfurization. In addition, since the mechanical separating means has many movable parts, a large number of experienced and skilled operators are required, and when there is a shortage of such operators, operation may be hindered. Furthermore, many malfunctions occur in the moving parts, which may lead to the interruption of operation. In addition, a wastewater treatment device was required to treat the remaining waste liquid from which the gypsum had been separated, which also required equipment costs and operating costs. For such economic and technical reasons, it has been strongly desired to realize a wet flue gas desulfurization method capable of separating gypsum by a low-cost means instead of a mechanical separation means.

In view of the above situation, an object of the present invention is to separate the generated gypsum by a low-cost means instead of a mechanical separating means, thereby maintaining the conventional desulfurization rate and reducing the equipment cost and operating cost. An object of the present invention is to provide an improved wet flue gas desulfurization method capable of significantly reducing the above.

[0005]

Means for Solving the Problems The present inventor has focused on a sedimentation separation method by gravity as an alternative to a mechanical separation means, and increases the particle size of gypsum crystal particles so that the generated gypsum can be easily separated by sedimentation. The method was studied and the present invention was devised. In order to achieve the above object, the wet flue gas desulfurization method according to the present invention comprises contacting flue gas containing sulfurous acid gas with an aqueous solution for dissolving or suspending a calcium-containing compound in the presence of oxygen in a reactor. In the wet flue gas desulfurization method, which comprises a reaction step of fixing sulfurous acid gas as gypsum, a step of extracting the gypsum produced in the reaction step as a gypsum slurry, and a step of separating gypsum from the gypsum slurry. The gypsum produced in the reaction step is retained for 10 to 30 hours in the reactor whose concentration is maintained in the range of 10 to 30% by weight, and then the gypsum is settled and separated by gravity in the separation step.

The reactor used in the method of the present invention is a reaction in which flue gas containing sulfurous acid gas and an aqueous solution for dissolving or suspending a calcium-containing compound are contacted in the presence of oxygen to fix sulfurous acid gas as gypsum. There is no particular restriction on the type of the reactor as long as it can be carried out, but a high throughput and compact jet bubbling reactor is preferably used. As described in detail later, a jet bubbling type reactor is typically Japanese Patent Publication No. 55-372.
95, Japanese Patent Laid-Open No. 64-18429, Japanese Patent Laid-Open No.
As disclosed in, for example, Japanese Patent Publication No. -72913, it is a reactor in which flue gas is jet-bubbled into an aqueous solution in which a calcium-containing compound is dissolved or suspended to bring them into contact with each other to cause a reaction.

In the present invention, the calcium-containing compound means a compound containing Ca, and as a typical example, limestone (CaCO ₃ ),
Examples include slaked lime (Ca (OH) ₂ ). The calcium-containing compound is brought into contact with the sulfurous acid gas in the flue gas in the reactor in the presence of oxygen to carry out the reaction shown in the following chemical formula 1.

[Chemical 1]

The gypsum produced in the reaction step in the reactor whose gypsum concentration is maintained in the range of 10 to 30% by weight is 10 to
By retaining for 30 hours, the average particle size of the gypsum crystal particles grows to a size in the range of 50 μm to 100 μm, and sedimentation separation by gravity becomes easy. Desirably, the gypsum slurry is adjusted to pH 6 to 8 and then transferred to the sedimentation separation step. As a result, V, Ni, C in the gypsum slurry
Heavy metals such as r and Fe are precipitated and separated together with gypsum by gravity, and the remaining supernatant liquid no longer contains any residue harmful to the reaction. Therefore, the supernatant liquid can be used again as water for preparing a limestone slurry. Therefore, since the water system can be configured as a closed system, wastewater treatment equipment is not required, and equipment costs and operating costs can be significantly reduced. For pH adjustment, alkaline compounds,
For example, solutions or suspensions of calcium-containing compounds are used.

Here, the residence time of gypsum is set to 10 to 30 hours, but if it is 10 hours or less, even if the gypsum concentration is high, the growth of crystal particles is insufficient and it is unsuitable for sedimentation separation by gravity. This is because even if the reactor is made to stay for 30 hours or more, it is impossible to expect further growth of gypsum crystal particles despite the increase in size of the reactor. The gypsum concentration in the reactor is set to 10 to 30% by weight because the crystal growth is inferior at 10% by weight or less, and the gypsum concentration becomes too high at 30% by weight or more and the extraction pump or the pipe may be blocked. Because there is.

By securing a volume of 10 to 30 times the amount of gypsum slurry withdrawn per hour in the lower part of the reactor, the residence time of gypsum can be maintained at 10 to 30 hours. Further, by adjusting the amount of gypsum slurry withdrawn, or by adjusting the limestone concentration of the limestone slurry so that the concentration of the gypsum slurry is 10% by weight, that is, by adjusting the amount of feed water contained in the limestone slurry. The gypsum concentration can be maintained at 10 to 30% by weight.

By growing gypsum crystals in the reactor under the above-mentioned conditions, a known gravity type sedimentation / separation device which does not require mechanical means, for example, a gravity sedimentation basin or the like is used, and a coagulant is used. Gypsum can be easily settled and separated from the gypsum slurry by gravity without the need for auxiliary agents such as. Further, to do it economically, as shown in FIG.
It is also possible to create a gravity sedimentation basin that is surrounded on all sides by a dike made of separated gypsum itself.

FIG. 1 is a simplified system diagram of an example of a suitable apparatus for carrying out the wet flue gas desulfurization method according to the present invention. In FIG. 1 showing the apparatus 10, reference numeral 12 is an underground tank type jet bubbling type reactor described later. Gypsum slurry,
It is pumped from the bottom of the reactor 12 by the gypsum slurry pump 14 and fed into the gravity settling tank 18 via the gypsum slurry pipe 16. In the gravity settling tank 18, the gypsum crystal particles naturally settle due to gravity and are deposited on the bottom of the gravity settling tank 18, and the supernatant liquid is extracted through the supernatant liquid extraction pipe 20.

FIG. 2 is a schematic explanatory view of the gravity settling tank 18. In the figure, 18a is a bank constructed with separated gypsum itself in order to surround the four sides of the pond, and 18b is the liquid surface of the gypsum slurry and also the water surface of the water after separating the gypsum from the gypsum slurry. . The gypsum slurry pipe 16 is arranged such that its tip is near the liquid surface or partially immersed in the liquid surface, and the supernatant liquid withdrawing pipe 20 overflows the remaining water in which the gypsum has settled and draws it out of the pond. Thus, the upper open end of the pipe is located at the liquid surface 18b. The gypsum slurry that has flowed in from the gypsum slurry pipe 16 flows in the direction of arrow V, and gypsum particles settle down due to gravity and gradually accumulate at the bottom of the pond. After flowing the distance d, the gypsum particles are almost completely settled and separated, and the remaining supernatant liquid is clear. The supernatant liquid overflows from the supernatant liquid discharge pipe 20 and is discharged to the outside of the gravity settling tank 18.

The distance d is a dimension having different properties depending on the particle size of the produced gypsum, and can be easily obtained by a known experimental method using an actual gypsum slurry. By digging up the gypsum deposited on the bottom of the gravity settling tank 18 by a suitable machine such as a shovel loader and stacking it on the bank 18a, the same gravity settling tank can be used for a long period of time with almost no operating cost. Also, gypsum can be used to easily provide another gravity settling basin. Desirably, a water-impermeable sheet 18c, such as a polyethylene sheet, is laid at the bottom of the gravity settling tank 18 to prevent water from permeating underground.

As described above, the supernatant liquid extracted is temporarily retained in the supernatant liquid reservoir 22 and then returned to the reactor 12 by the supernatant liquid pump 24 for reuse. The part is also sent to the limestone slurry tank 26 and used again as water for preparing the limestone slurry. In the limestone slurry tank 26, a limestone slurry is prepared from the crushed limestone and the supernatant by a conventional method, and the limestone slurry pump 28 feeds the limestone slurry into the reactor 12.
To the gypsum slurry pipe 16, a PH adjusting agent supply pipe 30 for adjusting the pH of the gypsum slurry is connected. still,
In FIG. 1, equipment not particularly related to the present invention, for example, limestone crushing equipment, a supply pipe of oxidizing air to the bottom of the reactor 12, cooling water for cooling the flue gas fed into the reactor 12 The supply pipes, chimneys, measuring instruments, etc. have been omitted.

A typical example of the jet bubbling type reactor has a structure as shown in the schematic view of FIG. In this figure, reference numeral 50 denotes a reactor, and in the upper part of this reaction tank, a smoke exhaust outlet chamber 52, a smoke exhaust inlet chamber 54, a number of smoke exhaust dispersion pipes 56, and a bottom gypsum slurry retention part 5
8 is provided with a stirrer 60 and an oxygen-containing gas ejection nozzle 62.

The flue gas inlet chamber 54 and the flue gas outlet chamber 52 are connected to a flue gas introduction duct 64 and a flue gas discharge duct 66, respectively, for introducing flue gas for desulfurization and for deriving desulfurized flue gas. Further, the flue gas inlet chamber may be provided with a cooling liquid nozzle or the like for ejecting a cooling liquid for cooling the flue gas into the flue gas, if necessary. The flue gas dispersion pipe 56 descends substantially vertically from the flue gas inlet chamber 54 and is arranged so that its lower end portion is immersed in the limestone slurry. Also, the reactor 50
Is provided with a limestone slurry supply pipe 68 below the lower end of the flue gas dispersion pipe 56 and a gypsum slurry withdrawal pipe 70 at the bottom.

The function of the conventional jet bubbling reaction tank 50 will be further described with reference to FIG. The limestone slurry is supplied from the limestone slurry supply pipe 68 to the reactor 50 and is retained in the lower portion of the reactor 50. On the other hand, the flue gas introduction 64 and the flue gas inlet chamber 54 are used to introduce flue gas containing sulfurous acid gas below the liquid surface of the limestone slurry from the lower opening end of the flue gas dispersion pipe 56. Upon introduction, flue gas is jetted out from the gas dispersion means 72 provided at the lower end opening of the flue gas dispersion pipe 56 in a jet form to bubble while being bubbled into the aqueous solution. As a result, a so-called jet bubbling layer A is generated below the liquid surface. A stirrer 60 provided in the lower part of the flue gas dispersion pipe 56 stirs the limestone / gypsum slurry in the reactor 12 to raise unreacted limestone upward and stir the generated gypsum crystals to precipitate the precipitate. Promote growth while preventing.

Sulfurous acid gas reacts with limestone in a limestone slurry in the presence of an oxygen-containing gas blown from an oxygen-containing gas jet nozzle 62 arranged at the bottom of the reaction tank, for example, air, and is fixed as gypsum. Gypsum hydrates and crystallizes. The flue gas from which the sulfurous acid gas has been removed rises up from the slurry level, passes through the flue gas inlet chamber penetrating portion (gas slicer) 74 that passes through the flue gas inlet chamber 54, and from the flue gas outlet chamber 52 to the flue gas outlet duct. It is discharged to the outside of the system through 66. on the other hand,
The gypsum slurry in which the crystallized gypsum is suspended is sent to the next separation step by the gypsum slurry pump 14 via the gypsum slurry withdrawing pipe 70.

In the method of the present invention, the residence time of gypsum is 10 to
Since it is necessary to secure a volume equal to 10 to 30 times the amount of gypsum slurry withdrawn per hour in order to maintain it for 30 hours, the size of the reactor becomes larger than the conventional one. Therefore, a preferable reactor for carrying out the method of the present invention is a jet bubbling type reactor,
A lower part for retaining an aqueous solution for dissolving or suspending the calcium-containing compound, and introducing flue gas on the lower part,
An upper part to be led out, the lower part is formed as an underground tank or a semi-underground tank consisting of a reactor wall made of concrete, and the reactor wall of the upper part is made of metal, FRP, or synthetic resin or rubber. The upper part of the upper part is supported by slidably abutting the lower end of the reactor wall of the upper part on a supporting surface provided on the top of the lower part of the reactor wall. The lower end portion of the reactor wall and the supporting surface of the lower portion of the reactor wall are characterized by being sealed by a water sealing mechanism.

In the above-mentioned preferred reactor, the lower wall of the reactor wall supporting the upper wall of the reactor wall is sealed by the water seal mechanism so that the lower wall of the reactor wall and the upper wall of the upper wall of the reactor wall are sealed. This is because the materials of the reactor walls are different from each other, and when they are directly joined, the joints are broken due to the difference in thermal expansion. In order to solve such a problem, in the present invention, the difference in thermal expansion is absorbed by sealing with a water sealing mechanism as shown in FIG.

In FIG. 3, 40 indicates a concrete wall forming the reactor wall of the lower portion, and 42 indicates a reactor wall of the upper portion. A step is provided on the inside of the concrete wall 40 along the entire length of the circumference thereof, and the lower end of the reactor wall 42 in the upper portion is attached to the upper surface 4 of the step via a slide base 44.
6 slidably abuts on and is supported by the upper surface 46. The slide base 44 is a commonly used plate-like member called a so-called shoe, which is made of a smooth material that slides easily, such as metal. The upper surface 46 is set to a position lower than the liquid level inside the reactor, and the height of the step is higher than the liquid level by at least the liquid column height of the internal pressure of the reactor (B in the figure). Is set. Thereby, the reactor can be water-sealed with the liquid between the step of the concrete wall 40 and the reactor wall 42. On the other hand, the reactor wall 42 is free to thermally expand by sliding on the upper surface 46 of the concrete wall 40, so that no breakage occurs at the supporting portion. In other words, the invention of such a water-sealing mechanism made it possible to realize this preferred example of the reactor.

By forming the lower part of the reactor with a concrete wall, the lower part of the reactor can be economically made into an underground tank or a semi-underground tank. As a result, not only the equipment cost of the reactor itself can be significantly reduced, but also the height of the reactor is lowered, so that the cost of lifting equipment such as stairs and stages above the reactor can be reduced. Furthermore, it is possible to install the reactor in the lower part of the flue gas stack, which can significantly reduce the length of the flue gas flue duct.

Another preferred example of an economical reactor for carrying out the method of the present invention is a flue gas inlet chamber in which the reactor is connected to a flue gas introducing duct for introducing flue gas, and a flue gas inlet chamber. A smoke exhaust outlet chamber disposed on the upper part, and the ceiling wall of the smoke exhaust inlet chamber also serves as a bottom plate of the smoke exhaust outlet chamber as a partition wall that defines the smoke exhaust inlet chamber and the smoke exhaust outlet chamber. In the formed jet bubbling type reactor, the partition wall is inclined downward from the side connected to the smoke exhaust introduction duct toward the opposing container wall to reduce the cross-sectional area of the smoke exhaust inlet chamber. It is characterized by that.

In the conventional typical jet bubbling type reactor, as shown in FIG. 5, the partition wall 76 defining the smoke exhaust inlet chamber 54 and the smoke exhaust outlet chamber 52 is the bottom plate 7 of the smoke exhaust inlet chamber 54.
8 was provided in parallel with each other, that is, both were horizontal, and the cross-sectional area of the smoke exhaust inlet chamber 54 in the advancing direction of smoke was constant. In the flue gas inlet chamber 54, flue gas proceeds from the side of the connection port 80 with the flue gas introduction duct 64 to the side opposite thereto, to the side where the flue gas derivation duct 66 is provided in FIG. While being dispersed in the slurry from the smoke exhaust dispersion pipe 56, the flow rate decreases.

Therefore, the cross-sectional area of the flow path required for letting in the flue gas, that is, the cross-sectional area of the flue gas inlet chamber 54 in the direction orthogonal to the advancing direction of the flue gas, can be reduced accordingly. is there. On the other hand, the cross-sectional area of the flow path necessary for discharging the smoke exhaust, that is, the cross-sectional area of the discharge outlet chamber 52 in the direction orthogonal to the discharge direction of the smoke exhaust is opposite to the cross-sectional area of the smoke exhaust inlet chamber. Increasing toward the direction of smoke emission, that is, toward the side where the smoke exhaust duct 66 is provided. With this in mind, the present inventor has invented the present preferred embodiment of the reactor.

In the present preferred embodiment, as shown in FIG. 4, the partition wall 76 which defines the smoke exhaust outlet chamber 52 in the upper part of the reactor and the smoke exhaust inlet chamber 54 provided in contact therewith is a smoke exhaust inlet. Duct 6
4 is inclined downward from the connection port 80 side to the opposite side. The required height of the partition wall 76 from the reference position on the side of the connection port 80 is the same as the conventional one, while the required height of the partition wall 76 from the reference position at the end on the opposite side is, to be exact, Although it can be easily obtained by a known designing method, there is practically no problem with the height being the same as that of the bottom plate 78 of the smoke exhaust inlet chamber 54 as shown in FIG.

As a result, the height of the upper portion of the jet bubbling type reactor can be reduced to about half that of the conventional jet bubbling type reactor, and the material cost can be reduced accordingly.

[0029]

EXAMPLES The method of the present invention was carried out as described below using the apparatus for carrying out the method of the present invention shown in FIG. Example 1 Reactor 12 adjusted to have a gypsum concentration of 20% by weight
The gypsum was allowed to stay in the reactor for 20 hours, and then the gypsum slurry was withdrawn from the reactor 12 and poured into the gravity settling tank 18. The distance between the gypsum slurry injection port of the gravity settling tank 18 and the overflow port of the supernatant liquid extraction pipe 20 is about 20 m.
Met. While the gypsum slurry moved from the gypsum slurry injection port to the overflow port of the supernatant liquid withdrawing pipe 20, gypsum crystal particles were precipitated, and the supernatant liquid was clear enough to be reused. The average particle size of the gypsum crystal particles in the gypsum slurry was 80 μm.

Example 2 A lime slurry having a concentration of 20% was poured into a gypsum slurry,
Gypsum was settled and separated from the gypsum slurry in the gravity settling tank 18 in the same manner as in Example 1 except that the pH was changed to 7. As in Example 1, the supernatant liquid was clear and the content of heavy metals was 1 ppm or less. Example 3 The gypsum was settled and separated from the gypsum slurry in the gravity settling tank 18 in the same manner as in Example 1 except that the residence time of the gypsum was 10 hours and the gypsum concentration was 15% by weight. As a result, the supernatant liquid became clear. It has been confirmed that Example 4 As a result of sedimentation and separation of gypsum from a gypsum slurry in the gravity settling tank 18 in the same manner as in Example 1 except that the residence time of gypsum was 30 hours and the gypsum concentration was 25% by weight, the supernatant liquid became clear. It has been confirmed that

Comparative Example 1 Gypsum was separated from the gypsum slurry in the gravity settling tank 18 in the same manner as in Example 1 except that the residence time of gypsum was 5 hours. The liquid extracted from the supernatant liquid extraction tube 20 was not clear but was observed to be suspended by fine gypsum crystal particles. The average particle size of the gypsum crystal particles in the gypsum slurry was 30 μm. Comparative Example 2 Gypsum was separated from the gypsum slurry in the gravity settling tank 18 in the same manner as in Example 1 except that the gypsum concentration was 5% by weight. The liquid extracted from the supernatant liquid extraction tube 20 was not clear, but the suspension of fine gypsum crystal particles was observed.

[0032]

According to the present invention, the gypsum concentration is 10 to 30.
In the separation step of separating the gypsum from the gypsum slurry by allowing the gypsum produced in the reaction step to stay for 10 to 30 hours in the reactor maintained in the range of wt% to largely grow the gypsum crystal particles. Instead of a mechanical separation means that is expensive and difficult to operate, it enables sedimentation separation of gypsum by gravity in a gravity settling tank that does not require a machine, and reuses the supernatant liquid to install a wastewater treatment device. It is unnecessary. By using the wet flue gas desulfurization method according to the present invention, the equipment cost and operating cost of the flue gas desulfurization apparatus can be significantly reduced while maintaining the conventional desulfurization rate. Further, by improving the jet bubbling type reactor used as the reactor, the wet flue gas desulfurization method can be carried out more economically.

[Brief description of drawings]

FIG. 1 is a system diagram of an example of an apparatus for carrying out the method of the present invention.

2 is a schematic cross-sectional view of a gravity settling tank of the apparatus shown in FIG.

FIG. 3 is an explanatory view showing a water sealing mechanism of a suitable reactor for carrying out the method of the present invention.

FIG. 4 is an illustration of another suitable reactor for carrying out the process of the invention.

FIG. 5 is an explanatory view of a conventional typical jet bubbling type reactor.

[Explanation of symbols]

 10 Apparatus for carrying out the method of the present invention 12 Reactor 14 Gypsum slurry pump 16 Gypsum slurry pipe 18 Gravity sedimentation tank 20 Supernatant extraction pipe 22 Supernatant liquid reservoir 24 Supernatant liquid pump 26 Limestone slurry tank 28 Limestone slurry pump 30 PH adjusting agent supply pipe 40 Concrete wall 42 Reactor wall in the upper part of the reactor 44 Sliding table 52 Smoke exhaust outlet chamber 54 Smoke exhaust inlet chamber 64 Smoke exhaust introduction duct 76 Partition wall

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akenori Ide 2-12-1, Tsurumi Chuo, Tsurumi-ku, Yokohama City Chiyoda Kako Construction Co., Ltd. (72) Shinichi Shimizu 12-12, Tsurumi-chuo, Tsurumi-ku, Yokohama No. 1 Chiyoda Kakoh Construction Co., Ltd.

Claims (4)

[Claims] 1. A reaction step in which flue gas containing sulfurous acid gas and an aqueous solution in which a calcium-containing compound is dissolved or suspended are contacted in the presence of oxygen in a reactor to fix the sulfurous acid gas as gypsum. A wet flue gas desulfurization method comprising a step of extracting gypsum produced in the reaction step as a gypsum slurry from the reactor, and further separating gypsum from the gypsum slurry, wherein the gypsum concentration is in the range of 10 to 30% by weight. A wet flue gas desulfurization method, characterized in that the gypsum produced in the reaction step is retained in the maintained reactor for 10 to 30 hours, and then the gypsum is settled and separated by gravity in the separation step. 2. The wet flue gas desulfurization method according to claim 1, wherein the gypsum slurry is adjusted to pH 6 to 8 and then the gypsum is separated from the gypsum slurry by gravity in the separating step. 3. The reactor is a jet bubbling type reactor, wherein a lower part for retaining an aqueous solution in which the calcium-containing compound is dissolved or suspended is retained, and the flue gas is introduced onto the lower part. , An upper part to be led out, the lower part is formed as an underground tank or a semi-underground tank consisting of a reactor wall made of concrete, and the reactor wall of the upper part is made of metal, FRP, or synthetic resin. Or made of rubber-coated metal, and supported by slidably abutting the lower end of the reactor wall of the upper part on a supporting surface provided on the top of the reactor wall of the lower part. The wet drainage according to claim 1 or 2, wherein the lower end portion of the reactor wall of the upper portion and the supporting surface of the reactor wall of the lower portion are sealed by a water sealing mechanism. Smoke desulfurization method. 4. The upper part of the reactor is provided with a flue gas inlet chamber connected to a flue gas introducing duct for introducing flue gas, and a flue gas outlet chamber arranged above the flue gas inlet chamber, Furthermore, a jet bubbling type reactor in which a ceiling wall of the smoke exhaust inlet chamber is formed as a partition wall that also serves as a bottom plate of the smoke exhaust outlet chamber to define the smoke exhaust inlet chamber and the smoke exhaust outlet chamber, 4. The partition wall is inclined downward from the connection side with the smoke exhaust introduction duct toward the opposing container wall to reduce the cross-sectional area of the smoke exhaust inlet chamber. The wet flue gas desulfurization method according to any one of 1.