JPH07194931A - Multi-tube gas-liquid contact device - Google Patents

Abstract

(57) [Abstract] [Purpose] In a multi-tube gas-liquid contactor having a structure in which a large number of gas inlet pipes having gas outlets on the lower peripheral wall are vertically suspended in a stationary liquid, the gas outlets (EN) Provided is a device capable of preventing the occurrence of large fluctuations of a floss layer in a liquid tank due to gas ejection. [Structure] In a large liquid tank, a large number of gas introducing pipes having gas ejection holes on the lower peripheral wall are provided in a liquid-liquid contact device in which the gas ejection holes are located below the stationary liquid surface in the liquid tank. The first partition member for partitioning into a plurality of compartments A in the liquid tank and the gas introduction pipes existing in the compartment A are surrounded by one or a plurality of gas introduction pipes to introduce one or a plurality of gases. A multi-tube gas-liquid contact device characterized in that a section B is formed around the tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-tube gas-liquid contactor for contacting a gas with a liquid (including slurry liquid), and more particularly to a multi-tube gas-liquid contactor suitable as a flue gas desulfurization device. is there.

[0002]

2. Description of the Related Art A liquid is contained in a large liquid tank, and a large number of gas introducing pipes having gas ejection holes on the lower peripheral wall are vertically provided in the liquid, and the gas introduced into the gas introducing pipe is ejected. Apparatuses for ejecting gas into a liquid through a hole to make gas-liquid contact are widely known (Japanese Patent Publication No. 55-37295, Japanese Patent Publication No. 57-6375, Japanese Patent Publication No. 59-11322, etc.).

FIG. 7 shows a schematic view of a conventional gas-liquid contact device used as a flue gas desulfurization device. In FIG.
Flue gas containing SO ₂ is discharged from the gas conduit 101 to the gas introduction pipe 1
A gas jet port provided on the lower peripheral wall surface of the gas introduction pipe 103 passes through 03 and is jetted into a slurry liquid of a calcium compound such as calcium carbonate or calcium hydroxide. In this case, the gas introduction pipe 103 has a gas ejection hole 104 arranged on the lower peripheral wall surface thereof, as shown in FIG. 8 or 9. The flue gas ejected into the slurry liquid of the calcium compound in the liquid tank comes into contact with the slurry liquid, and SO ₂ contained in the flue gas reacts with the calcium compound to become CaSO ₃ . Then, this CaSO ₃ reacts with oxygen in the air introduced into the liquid from the air introduction pipe 106 at the lower part of the liquid tank to cause Ca.
It becomes SO ₄ (gypsum). Incidentally, 112 is a gas-liquid separator for capturing the liquid in the gas, 105 is a stirring blade, and 108 is a gypsum slurry withdrawal pipe. The flue gas desulfurization device shown in FIG. 9 is actually a very large device,
The inner diameter of the liquid tank 102 is 10 m or more, usually 25 m or more, and the number of the gas introducing pipes 103 is an extremely large number of 1,000 or more.

In such a gas-liquid contact device, gas is ejected into the liquid from the gas ejection holes of the gas introduction pipe, and this causes the entire floss layer (foam layer) in the liquid tank. As a result, steady and periodic large fluctuations may occur. Then, due to the fluctuation of the floss layer, the upper surface of the floss layer in the liquid tank largely changes. The steady fluctuation of the floss layer causes a problem that it becomes larger as the liquid tank becomes larger.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a multi-tube type gas-liquid contactor having a structure in which a large number of gas introduction pipes having gas ejection holes on the lower peripheral wall are suspended in a stationary liquid. It is an object of the present invention to provide an apparatus capable of preventing the occurrence of a large fluctuation of the floss layer in the liquid tank due to the gas jet into the liquid.

[0006]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, according to the present invention, in a gas-liquid contactor in which a large number of gas introduction pipes having gas ejection holes on the lower peripheral wall surface in the large liquid tank are located below the stationary liquid surface in the liquid tank, A first partition member for partitioning the inside of the liquid tank vertically and horizontally to form a plurality of compartments A in the liquid tank, and a gas introduction pipe existing in the compartment A are surrounded by one or a plurality of them, and one or Provided is a multi-tube gas-liquid contactor characterized in that a section B is formed around a plurality of gas introduction tubes.

The material of the first and second partition members used in the present invention can be plastic, ceramic or the like in addition to metal. Further, the partition member can be a porous body (such as a wire mesh or a porous plate) or a corrugated plate.

FIG. 1 is an explanatory view of a compartment A formed by vertically and horizontally partitioning the inside of the liquid tank by the first partition member. Figure 1
1A is an explanatory plan view thereof, and FIG. 1B is a perspective view of a main part thereof. In FIG. 1, 10 denotes a liquid tank wall, 3 denotes a first partition member, and A denotes a partition formed by the partition member 3 (compartment A). In FIG. 1B, 1 indicates a gas introduction pipe, and 2 indicates a gas ejection hole. First partition member 3
Is made of a plate having a predetermined height, and the whole can be a lattice-shaped structure integrally formed. The height from the lower end to the upper end is 150-500m
m, preferably 200 to 400 mm, and its thickness is 100 to 300 mm, preferably 150 to 200 mm. The vertical / horizontal length ratio (n /
m) is 0.5 to 2.0, preferably 0.75 to 1.5
It is better to set the range. The length m or n of the longer side of the quadrilateral formed by the vertical length n and the horizontal length m of the section A is 0.5 to 2 m, preferably 0.75 to 1 ．
It is good to set it in the range of 5 m. A large number of gas introduction pipes are present in the compartment A, and the number thereof is usually 10 to 60, preferably 20 to 40, and more preferably 25 to 35. The lower end of the first partition member 3 may be located at the same level as the gas ejection hole 2 of the gas introduction pipe 1 or in the vicinity thereof (slightly above or slightly below the level of the gas ejection hole 2) or below the gas ejection hole 2. it can. The upper end of the first partitioning member 3 is above the upper surface of the floss layer described below in detail, at the same level as the upper surface of the floss layer or in the vicinity thereof (slightly above or slightly below the level of the upper surface of the floss layer) or below the upper surface of the floss layer. It can be located, but is preferably near the top of the floss layer.

The second partition member is for surrounding the gas introducing pipes existing in the section A shown in FIG. 1 one by one or a plurality of gas introducing pipes, and surrounds the one or a plurality of gas introducing pipes. A section B smaller than the section A is formed in the.

As the second partition member used in the present invention, a plate-like shape or a cylindrical shape may be used as long as it can divide a large number of gas introducing pipes suspended in the liquid into a single pipe or a plurality of pipes. Although any shape can be used, it is preferably a lattice-shaped structure integrally formed as a whole. In Figure 2,
The explanatory view of the division B formed by partitioning a large number of gas introduction pipes one by one using the second partition member is shown. In FIG. 2, 1 is a gas inlet pipe, 2 is a gas ejection hole formed in the lower peripheral wall surface, 13 is a second partition member, 4 is a stationary liquid surface in the liquid tank, and 5 is a floss layer in the liquid tank. The upper surface (expanded liquid surface), 6 is a floss layer formed from the level of the gas ejection holes 2 and above the gas ejection holes 2 and consisting of a mixture of bubbles and liquid. B is a section B formed by the partition member 13 and includes the gas introduction pipe 1 therein.

The second partitioning member 13 constitutes a partitioning wall in the section B and can be a cylindrical body, or a cylindrical body having a rectangular cross section such as a triangle or a quadrangle produced by combining plate bodies. Can be The lower end of the second partition member 13 is
The gas introduction pipe 1 is arranged so as to be positioned at the same level as the gas ejection holes 2 or in the vicinity thereof (slightly above or slightly below the level of the gas ejection holes 2) or below. Second partition member 1
The upper end of 3 is located above the upper surface 5 of the floss layer, at an intermediate portion between the gas ejection hole 2 and the floss layer, that is, at an arbitrary position between the gas ejection hole 2 and the upper surface 5 of the floss layer, for example, the start of operation of the apparatus. Between the front stationary liquid level 4 and the upper surface 5 of the floss layer, in the vicinity of the stationary liquid level 4, or in the intermediate portion between the gas ejection hole 2 and the stationary liquid surface 4, between the gas ejection hole 2 and the upper surface 5 of the floss layer. It can be arranged at a position such as a central portion between them. The distance between the outer peripheral surface of the gas introduction pipe 1 and the inner wall surface of the second partition member 13 is not particularly limited, but generally it may be 5 times or less the outer diameter of the gas introduction pipe 1. When the lower end of the second partition member 3 is located slightly above the gas jet 2, the position of the lower end is
The height from the level of the gas ejection holes 2 is 7.5 cm or less, preferably 0 to 5 cm. FIG. 3 shows an explanatory view of section B in an example in which the upper end of the second partition member 13 is arranged between the gas ejection hole 2 and the stationary liquid surface 4. In this case, the height of the upper end of the second partition member 13 from the level of the gas ejection hole 2 is 25 to 100%, preferably 40 to the distance between the gas ejection hole 2 and the stationary liquid surface 4. ~ 85%
It is better to position it so that Generally, the upper end is at a height from the level of the gas ejection hole 2 and is 5 to 50c.
m, preferably 10 to 30 cm. If the cross-sectional area of the section B is reduced, the lift effect due to the jetted gas in the section B is increased, the effect of sinking the liquid into the section B is increased, the circulation of the liquid is improved, and the stirring power of the liquid is increased. It also saves

FIGS. 2 and 3 are explanatory views of a bubble passage section formed by partitioning a large number of gas introduction pipes by using the second partition member 13 one by one, but one gas introduction pipe is shown. It is not necessary to partition each, and multiple partitions can be partitioned. This type of gas-liquid contactor is large in size, and the number of gas introduction pipes arranged in the liquid tank is as large as several thousand. In the present invention,
These gas introduction pipes are plural, for example, 2 to 16,
It is preferable to partition every 4 to 9 pieces.

According to the present invention, the second partition member 13 arranged so as to surround the gas introduction pipe in the compartment A can be supported in the liquid tank by any method. For example, a support may be provided above or below the stationary liquid level in the liquid tank and supported by the support, or in the form of a grid to support the gas introduction pipes in the liquid tank. It can be supported by a support.

The second partition member 13 used in the present invention is the first
It can be supported by the partition member 3, whereby the gas introduction pipe can be fixed at the same time. 4 and 5 are explanatory views of this case. FIG. 4 shows the second partition member 1.
It is explanatory drawing at the time of supporting 3 by the 1st partition member 3.
In this figure, 14 is a support body for supporting and fixing the second partition member 13 to the first partition member 3. This support 1
4, the lower end is joined to the second partition member 13, and the upper end is bent at a right angle, and the supporting member 13 is supported by placing the bent portion on the upper end surface of the first partition member 3. It is a thing. The second partitioning member 13 is formed in an integral lattice-shaped structure as a whole, and its perspective view is shown in FIG.

FIG. 5 is an explanatory plan view of the section A. Reference numeral 3 (1) to 3 (4) in FIG. 5 is a first partition member. As the first partition member, a conventional gas-liquid contactor is used to support a grid-like gas introduction pipe support. It is possible to use a main beam, a minor beam, and an auxiliary beam that are vertically and horizontally arranged in the liquid tank. For example, a main boom may be used as the first partition 3 (1), an auxiliary beam may be used as the first partition member 3 (2), and a minor boom may be used as the first partition members 3 (3) and 3 (4). it can. Each of the beams vertically and horizontally arranged in the liquid tank is wholly located entirely within the floss layer formed in the liquid tank, or at least 50 times the height of the floss layer.
It has been confirmed that at least 100% is reliably located in the floss layer and sufficiently functions as the first partition member 3 used in the present invention.

The principle of the gas-liquid contactor of the present invention will be described with reference to FIG. 2. When a gas is introduced into the gas introduction pipe 1 and the gas is ejected from the gas ejection holes 2 of the gas introduction pipe 1, The fine bubbles generated by the gas ejection move upward after the ejection and enter the compartment B formed by the second partitioning member 13 and rise in the compartment B, and the gas ejection holes 2 of the compartment B Above the level, a floss layer 6 composed of a mixture of bubbles and a liquid is generated above the level, and the upper surface of the floss layer is located above the stationary liquid level. In FIG. 2, 4 indicates a static liquid level before introducing gas into the gas introducing pipe 1, and 5 indicates
The upper surface (expansion liquid level) of the floss layer formed after introducing gas into the gas introducing pipe 1 is shown. The liquid in the liquid tank is sucked into the compartment B from the lower end opening of the compartment B formed by the second partition member 13, rises together with the bubbles in the compartment B, and is discharged from the upper end opening of the compartment B. It The gas jetted into the liquid tank becomes fine bubbles and efficiently contacts the liquid while rising in the section B and above the section B. And
Since the gas bubbles ejected from the gas ejection holes 2 of the gas introduction pipe 1 are gathered in the compartment B and rise in the compartment B, the kinetic energy of the liquid flow generated when the bubbles rise is in the compartment B. And is prevented from being transmitted to other parts, and as a result, the occurrence of large shaking of the floss layer in the liquid tank is prevented.

In the gas-liquid contactor of the present invention, when the upper end of the second partition member 13 is located at the intermediate portion between the gas ejection hole 2 and the floss layer upper surface 2 (see FIGS. 2 and 3), the liquid tank The upper part of the floss layer can be connected horizontally. By connecting the upper portion of the floss layer in the horizontal direction in this manner, the flow of the floss layer can be performed not only in the one section B but also in the other section B, and thus in the liquid tank. It is possible to make the concentrations of the dissolved components contained in the liquid contained in the whole uniform.
Further, even when the upper portion of the floss layer is connected in the horizontal direction in this manner, a partition wall by a partition member exists near the gas ejection holes, and the liquid generated suddenly when gas is ejected from the gas ejection holes Since the transfer of the flow energy to other parts is prevented, the occurrence of large fluctuations of the floss layer in the liquid tank is prevented. Further, in the present invention, since the first partition member 3 forms the compartment A surrounding the plurality of compartments B in the liquid tank, the gas ejected from the gas ejection holes 2 is formed into fine bubbles. The transfer of the rapid flow energy of the liquid to other parts when it rises as
The partition member 3 also prevents transmission to other parts.
Therefore, in the case of the present invention, the provision of the first partition member 3 more effectively prevents the occurrence of large fluctuations of the floss layer in the liquid tank.

[0018]

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Comparative Example 1 Inner diameter of 9.
Sulfurous acid gas (SO ₂ ) 55 discharged from a coal-fired boiler in an 8 m limestone gypsum multi-tube flue gas desulfurizer
When the flue gas containing 0 ppm was treated, the outlet SO ₂
A concentration of 26 ppm (desulfurization rate: 95.2%) was obtained, but in this case, a swaying phenomenon of a period of about 3.4 seconds was observed in the floss layer.

Example 1 In the apparatus shown in Comparative Example 1, in order to obtain the apparatus of the present invention, a beam (height 280 mm, thickness 150 mm) provided in the apparatus as the first partition member was used. Used as is. As a result, a total of 33 compartments A were formed in the device. Next, as a second partition member, the grid-like structure shown in FIG. 6 is lowered between the compartments A so that the lower end thereof is located 30 mm above the level of the gas ejection holes 2, and at this position, as shown in FIG. The beam was supported as shown in FIG. In this case, the height from the lower end to the upper end of the lattice structure shown in FIG. 6 was 100 mm. When the flue gas was treated in the same manner as in Comparative Example 1 using the device of the present invention having the compartment A and the compartment B thus formed, in this case, the occurrence of fluctuating floss layer was completely prevented, At the same time, the desulfurization rate improved to 97.0% and the SO ₂ concentration at the outlet decreased to 16 ppm.

[0021]

According to the present invention, the partition A of the liquid tank is formed by the first partition member, and the partition B surrounding the gas introduction pipe is further formed by the second partition member in the partition A. The abrupt flow energy of the liquid that occurs when the gas is ejected into the liquid from the gas ejection holes of the gas introduction pipe is temporarily sealed in those compartments B and A,
The flow energy of the liquid is much less transferred to the other compartments, and as a result the occurrence of large fluctuating froth layers in the liquid tank is prevented. In the conventional gas-liquid contact device, the flow energies of the liquid that occur when the gas is ejected into the liquid from the gas ejection holes of the gas introduction pipes do not interfere with each other because there is no partition member. However, there is a problem in that, as a whole, a large periodic fluctuating floss layer is generated and the upper surface of the floss layer is fluctuated so that the gas-liquid contact efficiency is deteriorated. As described above, since the compartment A and the compartment B are formed in the liquid tank, the rapid flow energy of the liquid caused by the gas ejection from the gas ejection holes is sealed in the compartment A and the compartment B, and the like. Since the transmission to the bubble passing section is prevented, the above-mentioned problems as found in the conventional gas-liquid contact device can be solved at once. In addition, in the section B, since the lift effect due to the jetted gas is obtained, the fresh liquid existing under the gas introduction pipe is swept upward in the section B and mixed with the bubbles in the section. There is an advantage. The gas-liquid contactor of the present invention is used as a reaction apparatus involving various gas-liquid contacts, for example, contact between an exhaust gas containing sulfurous acid gas and an alkaline liquid such as a slurry liquid of a calcium compound such as calcium carbonate or calcium hydroxide. It is preferably applied as a flue gas desulfurization device for performing the above, a carbon dioxide gas device for contacting an exhaust gas containing carbon dioxide with an alkaline liquid, and the like.
In particular, the device of the present invention can be advantageously used as a large-scale flue gas desulfurization device having a liquid tank diameter of 10 m or more, particularly 20 m or more.

[Brief description of drawings]

FIG. 1 is an explanatory view of an example of a section A formed by a first partition member. a: Plan view b: Perspective view of main part

FIG. 2 is an explanatory view of an example of a section B formed by a second partition member.

FIG. 3 is an explanatory diagram of another example of a section B formed by a second partition member.

FIG. 4 is an explanatory view when the second partition member is supported by the first partition member.

5 is an explanatory plan view of the inside of section A shown in FIG.

FIG. 6 shows a perspective view of a lattice-like structure used as a second partition member.

FIG. 7 shows a schematic view of a conventional gas-liquid contact device used as a flue gas desulfurization device.

FIG. 8 is a structural explanatory view of an example of a gas introduction pipe.

FIG. 9 is a structural explanatory view of another example of the gas introduction pipe.

[Explanation of symbols]

 1, 103 Gas introduction pipe 2, 104 Gas ejection hole 3 First partition member 4 Still liquid surface 5 Upper surface of floss layer 6 Floss layer 13 Second partition member 14 Support body 101, 102 Liquid tank 105 Stirring blade 106 Air introduction pipe 108 Gypsum slurry extraction pipe A Partition formed by the first partition member B Partition formed by the second partition member

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B01D 53/77 B01J 10/00 104 8822-4G B01D 53/34 125 Q

Claims (9)

[Claims] 1. In a liquid-liquid contacting device, wherein a large number of gas introducing pipes having gas ejection holes on a lower peripheral wall surface of a large liquid tank are located below a stationary liquid level in the liquid tank, A first partition member for partitioning the container into vertical and horizontal partitions to form a plurality of compartments A in the liquid tank, and a gas introduction pipe existing in the compartment A.
A multi-tubular gas-liquid contactor comprising a second partition member that surrounds each or a plurality of gas introduction pipes and forms a section B around one or a plurality of gas introduction pipes. 2. The apparatus according to claim 1, wherein the height from the lower end to the upper end of the second partition member is lower than the height from the lower end to the upper end of the first partition member. 3. The upper end of the first partition member is located near the upper surface of the floss layer formed in the liquid tank, the lower end thereof is located near the gas ejection holes of the gas introduction pipe, and the upper end of the second partition member. The apparatus according to claim 1 or 2, wherein is located between the upper surface of the floss layer formed in the liquid tank and the gas ejection hole of the gas introduction pipe. 4. The vertical / horizontal length ratio of the section A formed by the first partition member is in the range of 0.5 to 2.0.
The device according to any one of to 3. 5. The device according to claim 1, wherein the length / width ratio of the section A formed by the first partition member is in the range of 0.75 to 1.5. 6. The device according to claim 1, wherein the length of the long side of the quadrilateral section A formed by the first partition member is in the range of 0.5 to 2 m. 7. The device according to claim 1, wherein the length of the long side of the quadrilateral section A formed by the first partition member is in the range of 0.75 to 1.5 m. 8. The device according to claim 1, wherein the first partition member is a lattice-shaped structure. 9. The second partition member comprises a lattice-shaped structure, and the structure is supported by the first partition member.
The device of any one of to 8.