JP6142432B2 - Flue gas desulfurization method and flue gas desulfurization apparatus - Google Patents

Description

The present invention relates to a flue gas desulfurization by the seawater method, contacting the seawater and the exhaust gas to selectively absorb target component in the gas in the apparatus, the seawater method in which the absorption treatment to diffuse into sea water in the target component The present invention relates to a flue gas desulfurization method and apparatus .

  For example, since the combustion exhaust gas discharged from the power generation facility contains sulfur oxide, it is necessary to remove the exhaust gas before discharging it into the atmosphere. As equipment for removing sulfur oxides from exhaust gas, spray type absorption towers, perforated plate type absorption towers, packed tower type absorption towers and the like are generally known. Among these facilities, a porous plate type absorption tower (moretana type absorption tower) using “Moletana” manufactured by Kubota Kasui Co., Ltd. as a porous plate is used to make exhaust gas contact with exhaust gas on the porous plate. This is an apparatus for removing sulfur oxides therein, and has an advantage that the removal performance of sulfur oxides is higher than that of other absorption towers.

  As the contact liquid used in the perforated plate type absorption tower, those using a contact liquid such as sodium hydroxide, magnesium hydroxide, calcium hydroxide, calcium carbonate, seawater and the like are generally known. The method of using seawater in these contact liquids has the advantage that there is no by-product compared to other methods, and seawater that has absorbed sulfur oxides can be discharged into the sea.

JP 2001-129352 A

In the perforated plate type absorption tower, seawater descending from above and exhaust gas rising from below are in countercurrent contact on the perforated plate. By mixing seawater and exhaust gas on the perforated plate, sulfur oxides in the exhaust gas are removed.
Efficient contact with seawater on the perforated plate or on the surface of the packing is extremely important in order to increase the exhaust gas treatment efficiency (desulfurization efficiency).

  However, the present inventors have found that when the perforated plate type absorption tower is operated for a long period of time, the operating efficiency decreases as the operating time elapses. Furthermore, when the cause is pursued, marine life such as bivalves (for example, mussels (Mytilus galloprovincialis), green mussels (Perna viridis), etc.), fixed organisms (barnacles, etc.), etc. It was discovered that this is the reason why living organisms enter the device and stay inside the absorption tower.

Seawater used in flue gas desulfurization equipment is designed to prevent the inflow of marine organisms and foreign substances by installing a screen at the seawater intake. However, the size of larvae and juveniles of some shellfish (eg, mussels, green mussels, etc.) is as extremely small as 60-300 μm and easily passes through the screen. These adhere and grow on the inner surface of the pipe supplying seawater to the absorption tower, and shells that have left after death enter the absorption tower, causing internal clogging.
In fact, the present inventors were greatly surprised to see even large deposits of shell fragments that had detached after death on the Moretana of the flue gas desulfurization facility that had been operating for a long time.

Therefore, the main problem of the present invention is to provide a porous plate on the packing material, and to supply liquid onto the packing material through each opening of the porous plate, thereby improving the dispersibility of seawater with respect to the packing material. The purpose is to increase the efficiency of absorption treatment or the efficiency of treatment for diffusion from seawater.
Another problem is to ensure high treatment efficiency of the gas to be treated by allowing seawater to be distributed and supplied to the entire flow path of the packing material.
Furthermore, a problem peculiar to the seawater method is to prevent a decrease in contact efficiency associated with the invasion of marine organisms into the apparatus.

  The inventors of the present invention were based on the knowledge that efficient contact with seawater on a perforated plate or on the surface of a packing material is important for improving the contact efficiency (desulfurization efficiency) of exhaust gas. In order to further improve the treatment efficiency of the exhaust gas, if a porous plate is provided on the packing and seawater is supplied onto the packing through each opening of the porous plate, the dispersibility of the seawater with respect to the packing increases, and the contact efficiency of the exhaust gas is improved. I got new knowledge that it would increase.

In the present invention based on such knowledge, a regular packing having a flow passage having a substantially uniform cross-section with respect to the transverse cross section is provided in the tower facing to the side, and gas is blown into the tower below the tower, To blow up,
A porous plate having a number of substantially uniformly arranged openings above the regular packing is provided, and seawater dispersion supply means for supplying and supplying seawater to the upper surface of the porous plate is provided above the porous plate,
A flue gas desulfurization apparatus characterized in that a gas to be processed is brought into gas-liquid contact with a gas to be processed that moves upward and seawater that descends.

  According to the present invention, a porous plate is provided on the regular packing, and seawater is supplied onto the regular packing through each opening of the porous plate, so that the dispersibility of the seawater relative to the packing is enhanced and the gas contact efficiency is increased. be able to.

On the other hand, the seawater dispersion supply means includes a supply pipe and a number of downward supply nozzles communicating with the supply pipe, and supplies seawater to the perforated plate. At least a part of the supply nozzle opening is perpendicular to the opening of the perforated plate. , The flow of seawater supplied to the flow path of the regular packing through the opening of the perforated plate can be formed, and when viewed as the entire cross section of the tower, it becomes substantially uniform. The liquid can be dispersedly supplied to the entire flow path of the filling material. Therefore, the gas-liquid contact apparatus which shows high contact efficiency with gas is obtained.
On the other hand, the seawater dispersion supply means includes a supply pipe and a number of downward supply nozzles communicating with the supply pipe, and the supply nozzles have a structure in which the supply nozzles are uniformly distributed at a rate of ² / m ² to 4 / m ^2. Can be used.
Further, the supply nozzle diameter of the seawater dispersion supply means is preferably 50 to 150 mm, particularly 65 to 125 mm, and the cross-sectional area of the nozzle is preferably 0.002 to 0.018 m ² / piece. Furthermore, it is preferable that the number of apertures of the perforated plate is 6 to 135, particularly 13 to 65, in the projected area from the supply nozzle.

The present invention further provides a regular packing having a substantially uniform flow passage with respect to the cross section in the tower facing the ridge, and a gas is blown into the tower below and blown up inside the tower. None, providing a porous plate having a number of substantially uniformly arranged openings above the regular packing, and providing seawater dispersion supply means for supplying seawater to the upper surface of the porous plate above the porous plate,
There is provided a flue gas desulfurization method characterized in that the gas to be treated is treated by gas-liquid contact between the gas that blows up and the seawater that descends.

Also in this seawater method flue gas desulfurization method, the seawater dispersion supply means for supplying seawater to the perforated plate includes a supply pipe and a number of downward supply nozzles communicating with the supply pipe, and at least a part of the supply nozzle opening of the perforated plate It is desirable to coincide with the opening in the vertical direction.
The aperture diameter of the perforated plate facing this is preferably 5 to 20 mmφ, particularly 8 to 12 mmφ, and the aperture ratio is preferably 25 to 60%, particularly 30 to 40%.
The numerical aperture of the perforated plate is desirably 3000 / m ^{2 to} 7800 / m ² .

  It is desirable that the flow velocity at the tip of the supply nozzle is 1.0 to 3.0 m / sec, particularly 1.5 to 2.5 m / sec.

  It is preferable that the superficial velocity of the gas blown into the tower is 2.0 m / second to 3.2 m / second, and the flow rate of seawater immediately above the regular packing is 2.0 m / second or more. It is.

In the middle of the regular packing in the height direction, there are a large number of oblique flow passages of gas blown from below, and at least at the upper end portion, the flow passage that raises the obliquely rising gas passing through the oblique flow passage upward A form having is desirable.
It is desirable that the minimum passage diameter of the flow path in the height direction of the regular packing is 10 to 30 mm.

  The above is the outline of the present invention, which is a technical matter based on knowledge obtained through various experiments and long-term operation.

  As described above, the operation efficiency cannot be stabilized without preventing the contact efficiency from being lowered due to the invasion of marine organisms into the apparatus. The present inventors consider that the size of larvae and juveniles of marine organisms is 60 to 300 μm, and it is not possible to prevent intrusion into the piping for supplying seawater to the absorption tower. We searched for a technique to prevent this.

Here, the present inventors have focused on bivalves such as mussels as marine organisms that cause a reduction in operating efficiency in the apparatus. Here, the bivalve includes, for example, mussels, green mussels, and European mussels belonging to the mussel family mussels. For example, the size of adult mussels and green mussels is about 30-50 mm. Therefore, the idea is to catch this type of shellfish mainly on the perforated plate through the supply pipe and the supply nozzle of the seawater dispersed supply means for supplying seawater to the upper surface of the perforated plate. Then, the device was designed and operated.
However, some shellfish are small, such as larvae, or small, such as cracked in piping. Therefore, the small diameter portion passing through the opening of the perforated plate is dropped through the flow path of the regular packing.
Furthermore, shellfish captured on the perforated plate are bubbled by gas that blows from below in a liquid layer of seawater formed on the perforated plate, so that the shellfish do not block or clog the opening of the perforated plate. I found out that it was important to put it in a state.

According to the present invention, by providing a porous plate on the regular packing, and supplying seawater onto the regular packing through each opening of the porous plate, the dispersibility of the seawater with respect to the regular packing is improved, and contact with gas Efficiency can be increased.
In addition, it is possible to prevent a decrease in contact efficiency due to the invasion of marine organisms into the apparatus, and it is possible to achieve both improvement in contact efficiency and stable operation for a long time.

It is an example of installation of the flue gas desulfurization device of the present invention. It is an elevational view of an example of the flue gas desulfurization apparatus of the present invention. It is an elevation which shows the outline | summary of the gas-liquid contact apparatus of a comparative example. It is an elevation view of the other example which shows the outline | summary of the flue gas desulfurization apparatus of this invention. It is a principal part enlarged view of FIG. It is explanatory drawing of the example of flow velocity distribution. It is explanatory drawing of the example of regular packing, (a) is a perspective view, (b) is an assembly drawing of the corrugated sheet element. It is a longitudinal cross-sectional view of the example of an apparatus. It is explanatory drawing of the seawater dispersion pipe shown in a plane, and the example of nozzle arrangement. It is a perspective view which shows the other seawater dispersion | distribution supply means example. It is planar explanatory drawing which shows the example of a magnitude | size relationship between a supply nozzle and the opening of a perforated plate. It is a perspective view which shows the other example of a regular packing. It is explanatory drawing of the example of flow-down velocity distribution at the time of using the said other regular packing example. It is explanatory drawing of the example of flow velocity distribution from the perforated panel to the regular packing accompanying changing the opening shape of a perforated panel. It is explanatory drawing of the example of flow velocity distribution from the perforated panel to the regular packing accompanying change of arrangement | positioning of a perforated panel. It is explanatory drawing of the example of flow velocity distribution from the perforated plate to the regular packing accompanying change of the opening diameter of a perforated plate. It is the other example of installation of this invention.

  Hereinafter, preferred embodiments of the flue gas desulfurization apparatus of the present invention will be described with reference to the drawings. Note that the following description of the preferred embodiment is merely an exemplification, and is not intended to limit the application of the present invention or its use.

FIG. 1 shows an exhaust gas treatment facility using a flue gas desulfurization apparatus according to the present invention.
Sulfur was removed by an exhaust gas fan 51 that supplies combustion exhaust gas discharged from a thermal power plant or the like, a seawater method flue gas desulfurization device 50 that processes the exhaust gas supplied from the exhaust gas fan 51, and a seawater method flue gas desulfurization device 50 A chimney 52 that discharges gas, a seawater supply pump 53 that supplies seawater to the seawater method smoke treatment apparatus 50, a screen 54 that removes marine organisms in the seawater, and a seawater supply pipe 55 are included. Marine life is contained in the seawater supplied by the seawater supply pump 53. Among these marine organisms, small larvae that cannot be removed by the screen 54 adhere to the seawater supply pipe 55 and grow.
Seawater in the lower part of the seawater method flue gas desulfurization apparatus 50 is mixed with seawater 57 supplied separately in the wastewater treatment facility 56, and then subjected to aeration processing by an aeration blower 58 and discharged into marine seawater.

  FIG. 2 is an elevation (cross-sectional) view of the first embodiment of the flue gas desulfurization apparatus according to the present invention, which is applied as, for example, the seawater method flue gas treatment apparatus 50 of FIG.

  A supply port 2 for supplying exhaust gas (for example, combustion exhaust gas from a waste heat boiler in a power generation facility) G is provided on the lower side surface of the gas-liquid contact tower 1 as a basic component of the flue gas desulfurization apparatus. Further, on the upper surface of the gas-liquid contact tower 1, an exhaust port 6 for exhausting the treated exhaust gas TG that has undergone the treatment in the gas-liquid contact tower 1 is provided.

In addition, at the upper part of the gas-liquid contact tower 1, a supply pipe 3 for introducing fresh seawater SW as a contact liquid into the gas-liquid contact tower 1 and the fresh seawater supplied to the supply pipe 3 are connected. A number of nozzles 4 for injecting SW downward in the gas-liquid contact tower 1 are provided.
In this embodiment, “fresh seawater” SW is seawater led from the sea, and sulfur oxidation after absorption treatment performed on a perforated plate 5 in the gas-liquid contact tower 1 described later. Differentiated from seawater containing things. The fresh seawater can use the used cooling water which comes out of the condenser (condenser) of a boiler installation, and the brine which comes out of a seawater desalination installation other than what was directly taken in from the sea as mentioned above.

  In this 1st Embodiment, the supply pipe | tube 3 and the nozzle 4 comprise the seawater dispersion | distribution supply means of this invention. The shape of the outlet of the supply nozzle 4 is not limited to a round shape, a square shape, or a polygonal shape, but a round shape is preferable. The diameter of the supply nozzle 4 is preferably 50 to 150 mm, particularly 65 to 125 mm. The diameter of the supply nozzle 4 indicates the maximum length of the opening when the shape is a square or a polygon. The fresh seawater SW may contain solids such as shellfish and seaweed, which causes the nozzle to be blocked. Therefore, by setting the diameter of the nozzle 4 to 50 mm or more, shellfish can be passed, and seawater can be jetted while preventing the nozzle from being blocked. The diameter of the supply pipe 3 is also desirably 50 mm or more.

Further, below the supply pipe 3 and the nozzle 4 of the gas-liquid contact tower 1, a perforated plate (for example, Moretana) 5 having an aperture ratio of preferably 25 to 60%, particularly 30 to 40% is provided.
Openings 5a are formed in the perforated plate in the range of 3000 / m ^{2 to} 7800 / m ² .
The opening shape of the perforated plate is not limited to a round shape, a square shape, or a polygonal shape, but a round shape is preferable. The aperture diameter of the perforated plate is preferably 5 to 20 mm, particularly 8 to 12 mm. The opening diameter indicates the maximum length of the opening when the shape is a square or a polygon. By setting the thickness to 5 to 20 mm, impurities such as shellfish contained in fresh seawater sprayed from the seawater dispersion supply means easily fall onto the regular packing from the opening of the perforated plate, while the perforated plate 5 Therefore, it is possible to prevent the liquid from staying for a long time. Thus, by making the opening diameter on the porous plate smaller than the nozzle diameter of the seawater dispersion supply means, it becomes possible to collect impurities (particularly shellfish) contained in the seawater on the porous plate. The collected contaminants can be removed when the operation is stopped.

Many of the conventional flue gas desulfurization apparatuses using seawater simply have a structure in which a plurality of perforated plates (moretana) 5 are provided in the height direction, and are also called regular packing (also called “structural packing”. Structured packing). ) Is not provided.
On the other hand, as a gas-liquid contact device, there is also known a device in which a regular packing is provided and seawater is sprayed from above.
In the present invention, both are used together, and a regular packing 20 is provided below the perforated plate 5. Reference numeral 21 denotes a porous support member that supports the bottom surface of the ordered packing 20. The regular packing is not limited to a single stage, but a plurality of stages is desirable in order to increase the contact efficiency.

The exhaust gas G supplied from the supply port 2 installed on the lower side surface of the gas-liquid contact tower 1 is directed upward in the gas-liquid contact tower 1 through the flow path of the regular packing 20 and the opening of the porous plate 5 in order. Moving.
On the other hand, fresh seawater SW is supplied to the supply nozzle 4 through the supply pipe 3. The supply pipe 3 is also connected to a pipe for supplying a part of the seawater that has absorbed sulfur oxides stored below the gas-liquid contact tower 1, and the seawater can be circulated and used in accordance with the operation. . Fresh seawater SW sprayed downward from the supply nozzle 4 provided in the upper part of the gas-liquid contact tower 1 is formed of the exhaust gas G, the porous plate 5 provided in the middle part of the gas-liquid contact tower 1 and the regular packing 20. Counter-current contact is made in the upper end and in the flow path. Through the countercurrent contact, the sulfur oxide contained in the exhaust gas is absorbed by the fresh seawater SW and removed from the exhaust gas. The sulfur oxide that has absorbed the sulfur content in the exhaust gas is sent from the discharge port provided below the gas-liquid contact tower 1 to the wastewater treatment facility via the flow path.
At this time, the ratio (L / G) of the flow rate G (kg / m ² · hr) of the exhaust gas G to the flow rate L (kg / m ² · hr) of the fresh seawater SW is 3 or more, preferably 4 to 15 is there.
The treated exhaust gas TG from which the sulfur oxide has been removed is exhausted from an exhaust port 6 provided in the upper part of the gas-liquid contact tower 1. Further, the seawater that has absorbed the sulfur oxide falls downward in the gas-liquid contact tower 1.

  In the present invention, a regular packing 20 having a substantially uniform flow path with respect to the cross section is provided in a tower facing the vertical direction, and a gas to be treated (for example, exhaust gas G) is blown into the tower below the tower. The seawater dispersion supply means 3 and 4 for supplying the liquid in a state of being distributed with respect to the upper surface of the porous plate 5 above the porous plate 5 by providing the porous plate 5 having substantially uniform openings above the regular packing 20. The gas to be processed that blows up in the tower and the descending seawater are brought into gas-liquid contact to process the gas to be processed.

  According to such a form, the seawater supplied from the seawater dispersion supply means 3, 4 passes through the openings 5 a, 5 a... While diffusing in the surface direction on the porous plate 5, and each flow path 20 a of the regular packing 20. , 20a... Therefore, the dispersibility of the seawater is improved as compared with the case where the seawater is directly flowed down from the seawater dispersion supply means 3 and 4 to the respective flow paths 20a, 20a,. The gas-liquid contact efficiency is high.

Further, in the present invention, not only the gas-liquid contact on the perforated plate 5 but also the seawater supplied from the seawater dispersion supply means 3, 4 is caused to flow down to the flow paths 20 a, 20 a. A gas-liquid contact is intended.
Therefore, since the gas-liquid contact is made even in the process of passing through the respective flow paths 20a, 20a... Having long passages in the height direction of the regular packing 20, the gas-liquid contact time becomes long. High efficiency.

However, when the seawater supplied from the seawater dispersion supply means 3, 4 is caused to flow down to the flow paths 20 a, 20 a. There is a risk of creating a flow path 20a that does not pass.
On the other hand, when a large number of nozzles 4 are arranged, the cost of the seawater dispersion supply means 3 and 4 becomes high. However, in the present invention, when supplying seawater from each of the supply nozzles 4, the seawater supply position is set in advance in a state of diffusing in the surface direction on the perforated plate 5, thereby dispersing the regular filler 20. Supply is possible, and it is configured to smoothly pass through each of the flow paths 20a, 20a. As a result, even if the number of nozzles 4 is reduced, sufficient diffusibility of seawater is ensured.

In the example of FIG. 2, the configuration of the present invention, that is, a regular packing, a perforated plate having openings, and a seawater dispersion supply means for supplying seawater are provided in the example of FIG. 2. A plurality of stages can be provided at intervals.
The example of FIG. 4 shows an example in which a seawater dispersion supply means for supplying regular packing and seawater is provided, and further, a regular packing, a perforated plate having openings, and a seawater dispersion supply means for supplying seawater are provided thereabove. It was. In the example of FIG. 4, since the sea water flows uniformly in the upper regular packing by the sea water dispersion supply means and the perforated plate for supplying sea water in the upper stage, the perforated hole having an opening in the lower stage is intentionally provided. There is no need to install additional plates, and there is also a meaning to prevent pressure loss.

Next, a comparative experiment on gas-liquid contact efficiency was performed based on the following experimental conditions.
Experimental equipment: Absorption tower dimensions 1500mm x 1500mm and height 3000mm
Filling: Regular resin packing (300 mm height / module)
Filling height: 1-stage supply gas flow rate: 24,000 m ³ / H
Supply gas component: Air supply liquid flow rate: 144 m ³ / H
<Experiment 1>: No porous plate above the regular packing (configuration of FIG. 3)
<Experiment 2>: Perforated plate above the regular packing (configuration in FIG. 2)
Based on the results of this experiment, the number of nozzles required to obtain a predetermined gas-liquid contact efficiency was calculated.
According to the calculation result, in the case of Experiment 1, it was necessary to arrange about 20 nozzles / m ^2, whereas in the case of Experiment 2, the arrangement of about 4 nozzles / m ² is sufficient. I found out.

  Next, another embodiment of the absorption tower is shown in FIGS. Also in this example, a plurality of seawater dispersion supply means 3 and 4 can be provided in the height direction. FIG. 9 is a plan view of the seawater dispersion supply means. As shown in FIG. 8, the seawater dispersion supply means of this structure is provided with a supply pipe 3 for carrying seawater supplied from the outside, and a number of downward supply nozzles 4 communicating with this. The supply pipe 3 communicates with the supply liquid supply nozzle X on the lower side surface of the absorption tower body, extends horizontally toward the center of the flat section of the absorption tower body, and extends upward from the vicinity of the center. Moreover, after extending | stretching above the regular packing filled in the absorption tower, it branches in a horizontal direction and the downward supply nozzle 4 is provided in each branched piping.

The supply nozzle is preferably dispersedly arranged at a rate of 1 / m ^{2 to} 100 / m ² , more preferably 2 / m ^{2 to} 6 / m ² . If the number of supply nozzles is excessively increased, the weight of the seawater dispersion supply means will increase. In particular, since the seawater dispersion supply means is installed above the absorption tower, the center of gravity of the entire absorption tower is increased, and a large-sized foundation is required.
Another example of a sea water dispersion feeding means, as shown in FIG. 10, includes an upper opening conduit, the outlet weir openings formed in its side wall, the weir opening two / m ² to 50 pieces / It may have a structure in which it is distributed at a ratio of m ² .

The exhaust gas G supplied from the supply port 2 installed on the lower side surface of the gas-liquid contact tower 1 is directed upward in the gas-liquid contact tower 1, opening of the porous support member 21 (see FIG. 8), regular packing The 20 flow paths and the opening of the porous plate 5 are moved in order.
On the other hand, fresh seawater SW sprayed downward from the supply nozzle 4 provided in the upper part of the gas-liquid contact tower 1 is exhaust gas G, on the perforated plate 5 provided in the middle part of the gas-liquid contact tower 1 and regularly packed. Countercurrent contact is made in the upper end of 20 and in the flow path. Through the countercurrent contact, the sulfur oxide contained in the exhaust gas is absorbed by the fresh seawater SW and removed from the exhaust gas. As shown in FIG. 8, an eliminator 22 for removing mist in the treated exhaust gas G is preferably provided above the nozzle 4.

In the case of the seawater flue gas desulfurization apparatus, the superficial velocity of the gas to be treated that blows up inside the tower 1 is set to 2.0 m / sec to 3.2 m / sec in relation to the required gas processing amount and the apparatus size. desirable.
This factor creates new problems. That is, at first, the present inventors finally distribute the seawater discharged from the seawater dispersion supply means 3 and 4 on the perforated plate 5, so that the nozzle may be discharged upward. I thought.
However, because the superficial velocity of the rising gas is high, if even a slight gas drift occurs in the cross section above the perforated plate, the seawater will be affected by the gas drift and drift down with respect to the cross section. It was discovered that
Therefore, it is desirable to supply seawater by installing the supply nozzle downward. When applied as a seawater method flue gas desulfurization apparatus, it is desirable that the flow rate of seawater immediately above the regular packing 20 is 2.0 m / second or more, particularly 2.5 m / second or more.

As a result of further various studies, the present inventors have found that as shown in FIG. 6, many liquid flows (centers) flowing down with respect to the upper surface of the porous plate 5 supplied by the seawater dispersion supply means 4 It was found that it is desirable to substantially coincide with the center of the opening 5a in the vertical direction.
Seawater flowing down from the seawater dispersion supply nozzle 4 diffuses in the surface direction while rebounding on the perforated plate 5. Usually, since the ratio (L / G) of the flow rate G (kg / m ² · hr) of the exhaust gas G to the flow rate L (kg / m ² · hr) of fresh seawater SW is 4 to 15, the seawater perforated plate 5 to form a liquid layer. The depth of the liquid layer at this time is 5 mm to 200 mm in a state where the exhaust gas G is not supplied. Further, the liquid layer is fluidized violently due to the rise of exhaust gas. Furthermore, the clogging of the opening 5a of the perforated plate 5 is prevented while fluidizing impurities such as shellfish.
However, when the position of the liquid flow flowing down from the seawater dispersion supply nozzle 4 with respect to the upper surface of the porous plate 5 substantially coincides with the position of the opening 5a of the porous plate 5 in the vertical direction, the kinetic energy of the flowing-down liquid is There is a clear advantage over the rising gas energy.
As a result, a peak is shown at a position that substantially coincides with the center of the opening 5a of the perforated plate 5 in the vertical direction as in the flow velocity distribution shown in FIG.
Then, when a large number of peaks are shown in the cross section where the flow velocity distribution is present, the kinetic energy of the flowing liquid is much more dominant than the rising gas flow at the peak position. Thus, the liquid starts flowing down from the flow path, and the liquid surely flows into the flow path 20a of the regular packing 20. Moreover, since the liquid flows from the perforated plate 5 not only at the positions of the openings 5a but also in a dispersed state, the liquid flows into the flow paths 20a of the regular packing 20 and flows down. Become.

  The minimum passage diameter of the flow path in the height direction of the regular packing 20 is preferably 10 to 30 mm. A part of the foreign substance floating on the perforated plate 5 is preferably dropped through the opening 5a, passes through the regular packing 20, and flows down from the lower end. For this reason, it is preferable that the minimum passage diameter of the oblique flow passage 20A, the flow passage 20B, and the flow passage 20C of the regular packing 20 described below is 10 to 30 mm. When the minimum passage diameter is 10 to 30 mm, the aperture diameter of the perforated plate is greatly related to 5 to 20 mmφ. However, since most of the foreign substances are floating and staying on the perforated plate 5, The diameter is set as a diameter that allows the contaminants that have passed through to flow smoothly.

The seawater dispersion supply means includes a supply pipe 3 and a number of downward supply nozzles 4 communicating with the supply pipe 3, and the supply nozzles are dispersedly arranged at a rate of ² / m ² to 50 / m ² as an example. Can be mentioned. In addition, the supply nozzle diameter of a seawater dispersion | distribution supply means is 50 mm-150 mm, More preferably, it is 65 mm-125 mm.
FIG. 11 shows an example of the size of the supply nozzle 4 aperture and the aperture 5a of the perforated plate 5 and the positional relationship of the aperture 5a of the perforated plate 5 on the flow-down projection area with respect to one supply nozzle 4 aperture.
A positional relationship in which 6 to 135 apertures of the perforated plate are included in the projected flow area of one supply nozzle 4 is preferable, and a positional relationship in which 13 to 63 apertures are included is particularly preferable. FIG. 11 shows about 13 examples. Since a plurality of apertures of the perforated plate are included in the flow-down projected area of one supply nozzle 4, even if one of the openings 5a of the perforated plate 5 located below the supply nozzle 4 is closed, the remaining aperture 5a Since at least one of these will show the peak of a flow-down speed, seawater can be reliably supplied to the regular packing 20.

On the other hand, as shown in FIG. 10, the seawater dispersion supply means includes an upper opening conduit 40 and an outflow weir opening 40B formed in the side wall 40A, and the weir opening 40B is 2 / m ² to 50 / m. ^It may be a form that is distributed at a ratio of ² .

As the regular packing of the present invention, for example, the regular packing 20 shown in FIG. 7 can be used. When this is described, a large number of corrugated sheets A and B having different wave crest directions of 90 degrees are used. By alternately stacking layers, a large number of channels whose continuous directions differ by 90 degrees are formed. Note that the crossing angle may be another angle (for example, 45 or 60 degrees), or a channel whose channel is not inclined can be used.
As such an appropriate volume size, the regular packing 20 is spread in the tower 1, and this spread can be performed in one stage or in appropriate plural stages. When the regular packing 20 is spread, the directionality can be changed for each single regular packing 20 so that the flow path direction becomes more random.

  On the other hand, as shown in FIGS. 12 and 13, in the middle of the regular packing 20 in the height direction, there are a large number of oblique flow passages 20A for gas blown from below, and at least at the upper end portion, the oblique flow passages. It can be set as the form which has the flow path 20B which raises the diagonally ascending gas which passes through 20A to the soot direction. A flow path 20 </ b> C that guides upward in the heel direction can also be provided at the lower end portion.

In the case of this mode, as described above, since the blown gas rises regularly in a vertical direction, it is possible to prevent the drifting of the descending seawater. An example of the flow velocity distribution when the other regular packing examples are used is shown in FIG.
The regular packing is not limited to the listed examples, and various commercially available or known regular packings can be used.

  In addition, as the relationship between the flow-down cylinder portion of the seawater of the supply nozzle 4 and the opening 5a of the perforated plate, the number of openings 5a immediately below the supply nozzle 4 is reduced as shown in FIG. A technique such as reducing the diameter of the opening 5a immediately below the supply nozzle 4 in FIG. 16 can be appropriately employed to determine the flow mode of the flow-down liquid into the regular packing.

  FIG. 17 shows a marine desulfurization apparatus as another installation example of the flue gas desulfurization gas-liquid contact tower. In this example, the exhaust gas discharged from the ship engine 61 mounted on the ship 60 is processed using the flue gas desulfurization tower 50A of the present invention. A marine engine (diesel engine tower) that drives the marine vessel 1, a seawater flue gas desulfurization tower 50A that processes exhaust gas from the marine engine 61, a water absorption pump 62 that supplies seawater to the seawater flue gas desulfurization tower 50A, marine organisms in the seawater A screen 63 that removes the exhaust gas, an exhaust gas fan 68 that discharges the exhaust gas treated in the flue gas desulfurization tower 50A to the atmosphere, a chimney 64, a seawater storage tank 65 that stores seawater that has absorbed sulfur oxides in the seawater flue gas desulfurization tower 50A, A wastewater treatment device 66 for removing impurities therein and an outflow pipe 67 are provided.

The seawater flue gas processing tower has the same structure as the first embodiment. By contacting the combustion exhaust gas of the diesel engine with seawater, sulfur oxides in the combustion exhaust gas are absorbed into the seawater.
Seawater that has absorbed sulfur oxides is discharged into the sea through the discharge pipe 67.

  The seawater method flue gas desulfurization apparatus disclosed in the present invention is not only a desulfurization process that absorbs sulfur in exhaust gas, but also equipment that absorbs hydrogen chloride into water and recovers hydrochloric acid, and nitrogen oxides in exhaust gas into seawater. It can be applied to a known absorption process such as a facility for absorbing and removing. Further, it can be applied to a diffusion process in which organic substances in wastewater are diffused into gas by air or steam.

DESCRIPTION OF SYMBOLS 1 ... Gas-liquid contact tower 2 ... Supply port 3 ... Supply pipe 4 ... Nozzle 5 ... Perforated plate (Moretana)
5a ... Open 6 ... Exhaust port 20 ... Regular packing (structure packing)
G ... exhaust gas TG ... treated exhaust gas SW ... fresh seawater

Claims (8)

A regular packing having a substantially uniform flow path with respect to the cross section is provided in the tower facing toward the ridge, and the gas to be treated is blown into the tower below and moved upward in the tower. None ,
A porous plate having a number of substantially uniformly arranged openings above the regular packing is provided, and seawater dispersion supply means for supplying and supplying seawater to the upper surface of the porous plate is provided above the porous plate,
The aperture diameter of the porous plate is 5 to 20 mm, and the aperture ratio is 25 to 60%.
The seawater dispersion supply means includes a supply pipe and a plurality of supply nozzles communicating with the supply pipe, and the diameter of the supply nozzle is 50 to 150 mm.
The superficial velocity of the gas to be treated is more than 2.0 m / second to 3.2 m / second,
The ratio (L / G) of the flow rate G (kg / m ² · hr) of the gas to be treated and the supply flow rate L (kg / m ² · hr) of seawater is 4 to 15,
On the perforated plate, a liquid layer is formed with seawater, and the gas to be processed and the descending seawater are brought into gas-liquid contact,
In the flow path of the regular packing, gas to liquid contact the gas to be processed that moves upward and the seawater that descends,
The flue gas desulfurization method, wherein the gas to be treated is treated. The flue gas desulfurization method according to claim 1 , wherein the numerical aperture of the perforated plate is 3000 / m ^{2 to} 7800 / m ² . The seawater dispersion supply means has a plurality of openings for supplying seawater to the perforated plate, and at least a part of the openings is such that the center of the opening coincides with the opening of the perforated plate in the vertical direction. Flue gas desulfurization method . ^2. The flue gas according to claim 1 , wherein the seawater dispersion supply means includes a supply pipe and a number of downward supply nozzles communicating with the supply pipe, and the supply nozzles are dispersedly arranged at a rate of ² / m ² to 50 / m ^2. Desulfurization method. The seawater dispersion supply means includes a supply pipe and a number of downward supply nozzles communicating with the supply pipe. The supply nozzle has a diameter of 50 to 150 mm, and the aperture of the perforated plate is 6 in the flow-down projected area from one supply nozzle. 2. The flue gas desulfurization method according to claim 1 , wherein the flue gas desulfurization method is installed at a position where 1 to 135 pieces are included, and the flow velocity at the tip of the supply nozzle is 2.0 to 3.0 m / second. In the middle of the regular packing in the height direction, there are a large number of oblique flow passages of gas blown from below, and at least at the upper end portion, the flow passage that raises the obliquely rising gas passing through the oblique flow passage upward The flue gas desulfurization method according to claim 1 . The flue gas desulfurization method according to claim 1 , wherein a minimum passage diameter of the flow path in the height direction of the regular packing is 10 to 30 mm. A regular packing having a substantially uniform flow path with respect to the cross section is provided in the tower facing toward the ridge, and the gas to be treated is blown into the tower below and moved upward in the tower. None ,
A porous plate having a number of substantially uniformly arranged openings above the regular packing is provided, and seawater dispersion supply means for supplying and supplying seawater to the upper surface of the porous plate is provided above the porous plate,
The aperture diameter of the porous plate is 5 to 20 mm, and the aperture ratio is 25 to 60%.
The seawater dispersion supply means includes a supply pipe and a plurality of supply nozzles communicating with the supply pipe, and the diameter of the supply nozzle is 50 to 150 mm.
On the perforated plate, a liquid layer is formed with seawater, and the gas to be processed and the descending seawater are brought into gas-liquid contact,
In the flow path of the regular packing, gas to liquid contact the gas to be processed that moves upward and the seawater that descends,
A flue gas desulfurization apparatus for performing the method according to any one of claims 1 to 7, which is configured to treat the gas to be treated.

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