JP5520525B2 - Desulfurization apparatus and exhaust gas cooling method - Google Patents

Description

The present invention relates to a desulfurization apparatus that removes SO _x in flue gas (combustion exhaust gas) and an exhaust gas cooling method that cools exhaust gas introduced into the desulfurization apparatus.

For example, in a facility that generates flue gas as combustion exhaust gas, such as a thermal power plant, desulfurization of flue gas is performed to prevent air pollution caused by flue gas containing sulfur oxides (SO _x ) such as sulfurous acid gas (SO ₂ ). A device is provided.
As one type of such flue gas desulfurization apparatus, sulfurous acid gas contained in the exhaust gases (SO _2), limestone aqueous solution dissolved or suspended (CaCO ₃₎ (sulfurous acid gas neutralizing agent slurry solution) absorption Those which are brought into contact with a liquid and react and absorb in the absorbing liquid are widely known (for example, see Patent Document 1).

  FIG. 2 shows the configuration of the main part of this type of conventional desulfurization apparatus. The absorption tower 1 that forms the main part of this desulfurization apparatus has an upper deck 3 and a lower deck 2 that are spaced apart in the vertical direction in the upper space. These decks 2 and 3 are provided as partition walls that hermetically define the internal space of the absorption tower 1, and the lower space of the lower deck 2 is the absorbent storage section (storage tank) 4, the upper deck 3, and the lower deck The space between the two is an exhaust gas introduction part 6, and the upper space of the upper deck 3 is an exhaust gas discharge part 8. Inside the absorption liquid storage section 4, an absorption liquid K made of an aqueous slurry of limestone is stored at a predetermined liquid level. In addition, an inlet duct 5 for introducing exhaust gas into the absorption tower 1 is connected to the exhaust gas introduction section 6, and an outlet duct 7 for extracting processed exhaust gas in the absorption tower 1 to the outside is connected to the exhaust gas outlet section 8. Has been. In addition, the inlet duct 5 is provided with a spray nozzle 16 for circulating and supplying a part of the absorbing liquid K from the cooling line 11 by the pump 13 and spraying the absorbing liquid as cooling water on the introduced exhaust gas for cooling. A gas cooling unit 17 is provided.

  A number of openings are formed in the lower deck 2 in a distributed manner, and the upper ends of sparger pipes (gas dispersion pipes) 9 that are suspended from the lower surface of the lower deck 2 are connected to the openings. The sparger pipe 9 extends downward, and the lower end portion is inserted into the absorbing liquid K in the absorbing liquid storage section 4 so that the exhaust gas is jetted and dispersed under the surface of the absorbing liquid K. .

Further, between the lower deck 2 and the upper deck 3, a gas riser 10 that communicates the upper space 4 a above the liquid level of the absorbent in the absorbent reservoir 4 with the exhaust gas outlet 8 passes through the exhaust gas inlet 6. It is provided in the form. Further, an air supply pipe for ejecting oxidizing air and a stirrer for stirring the absorption liquid K are provided on the bottom side of the absorption liquid storage section 4, and the base end side of the supply pipe is pumped with air. It is connected to the blower.
The absorption tower 1 is connected to a supply line for supplying a replenishing absorption liquid (limestone as an absorbent) into the absorption tower 1.
In addition, a spray nozzle 18 is disposed on the sparger pipe 9 in order to wash out gypsum adhering to the surface of the gas riser 10 and a lump of gypsum dropped from the gas riser 10 to the sparger pipe 9 as will be described later. A spray nozzle 19 is arranged around 10. And the filtrate at the time of isolate | separating gypsum from an absorbing solution is supplied to these spray nozzles 18 and 19 through piping, and it sprays intermittently.

In the absorption tower 1 having the above-described configuration, when exhaust gas is pumped from the inlet duct 5 to the exhaust gas introduction unit 6 while supplying oxygen (air) into the absorption liquid K through the supply pipe, the exhaust gas is converted into each sparger pipe. 9 is ejected from the ejection hole at the lower end of 9 and mixed vigorously with the absorbing liquid K to form a liquid phase continuous jet bubbling layer. At this time, the agitator is rotated to stir the absorbing liquid K, and the oxidizing air supplied from the supply pipe is continuously supplied into the absorbing liquid K from the nozzle at the tip of the supply pipe. As a result, highly efficient gas-liquid contact is performed in the jet bubbling layer, and it is contained in the exhaust gas as shown by SO ₂ + CaCO ₃ + 1 / 2O ₂ + H ₂ O → CaSO ₄ .2H ₂ O ↓ + CO ₂ ↑ As the sulfurous acid gas (SO ₂ ) is oxidized, a reaction that is neutralized by the limestone in the absorbent K is performed, and the sulfurous acid gas is absorbed and removed. Thus, the desulfurized exhaust gas is exhausted from the chimney to the outside through the gas riser 10, the exhaust gas outlet 8 and the outlet duct 7.

On the other hand, gypsum (CaSO ₄ .2H ₂ O) produced in the absorption liquid by oxidizing and neutralizing sulfurous acid gas (SO ₂ ) becomes an absorption liquid gypsum slurry by crystal growth and coarse particles, When the gypsum concentration in the absorption liquid reaches a predetermined concentration, it is extracted from the absorption tower 1 by a slurry pump and separated into mother liquor (filtrate) and gypsum. The separated filtrate is once stored in the slurry tank as a replenishing absorption liquid, and the replenishing absorption liquid passes through the supply line in accordance with the output of the liquid level meter in the absorption liquid storage section 4. 1 is supplied.
In addition, industrial water or the like is supplied as make-up water into the absorption tower 1 in order to replenish the water in the absorption liquid storage section 4 that decreases due to evaporation or the like. The exhaust gas sprayed and introduced from 14 is cooled and then flows into the absorption tower 1, and finally reaches the absorption liquid storage section 4.

According to the flue gas desulfurization apparatus using the absorption tower 1 as described above, stirring is performed by a stirrer while supplying oxidizing air into the absorbing liquid, and exhaust gas is ejected from the lower end of each sparger pipe 9 to Since the liquid-phase continuous jet bubbling layer is formed, all the steps of absorption, oxidation, neutralization and gypsum crystallization of sulfurous acid gas (SO ₂ ) in the exhaust gas can be performed in one tank, which is extremely high There is an advantage that sulfurous acid gas can be removed at a high rate.

JP-A-8-206435

By the way, in the above-mentioned desulfurization apparatus, while supplying the slurry-like absorption liquid containing gypsum to the gas cooling part of the inlet duct as described above, and spraying this absorption liquid (circulation liquid) with a spray nozzle, Humidification and cooling of the exhaust gas introduced into the absorption tower is performed.
In addition, since the exhaust gas and the absorbing liquid are corrosive to the metal in the members in the absorption tower, for example, FRP (fiber reinforced plastic) using synthetic resin or synthetic resin is lined with carbon steel (glass flakes). Many linings are used, and if high-temperature exhaust gas is introduced as it is, the FRP or glass flared lining members are affected by heat, so it is necessary to cool the exhaust gas.
In addition, the evaporation of moisture due to the introduction of high-temperature exhaust gas generates a gypsum scale based on the gypsum in the absorption liquid in the absorption tower. Is prevented.

  However, since the absorption liquid used for cooling contains a lot of particulate gypsum, the gypsum contained in the sprayed absorption liquid adheres to the surface of the gas riser of the exhaust gas introduction part when introducing the exhaust gas. There was a problem that.

  In addition, for example, when continuous operation is performed for a long time at a thermal power plant or the like, it is difficult to perform maintenance in the absorption tower, and by continuously using the desulfurization apparatus for a long time, the gas riser The gypsum adhering to the surface gradually became thicker. For example, gypsum that had become agglomerated under its own weight sometimes peeled off from the gas riser surface. In this case, the upper deck openings of the sparger pipes are arranged vertically and horizontally on the lower deck on the lower side of the gas riser, and a large number of the sparger pipes are arranged relatively close to each other. There is a possibility that the opening of one or a plurality of sparger pipes may be blocked by the lump. Further, after the gypsum lump has fallen into the sparger pipe, it could not be completely dropped and stopped in the sparger pipe, resulting in a partially clogged sparger pipe.

In this way, if the number of sparger pipes where the opening on the side of the exhaust gas inlet is clogged with gypsum or gypsum clogged inside increases with long-term continuous use, the number of sparger pipes that can introduce exhaust gas into the absorbent decreases It will be. As a result, the pressure loss of the introduced exhaust gas increases, and the running cost of the fan that introduces the exhaust gas increases.
Therefore, for example, as described above, there are cases where a spray nozzle is disposed on the sparger pipe or around the gas riser and the filtrate obtained when the above-mentioned gypsum is separated is sprayed.

However, because the amount of filtrate is limited, the filtrate could not be sprayed continuously, and because it was sprayed intermittently, the gypsum adhering around the gas riser could not be removed sufficiently. After all, there was a possibility that the thickened plaster might fall into the upper end opening of the sparger pipe.
Moreover, even if the filtrate is sprayed onto the sparger pipe, it is intermittent and the amount of liquid is low, so the plaster that falls on or inside the sparger pipe cannot be completely washed away, eliminating the clogging of the sparger pipe. It was not enough to do.
In addition, the liquid level of the absorbing liquid in the absorbing liquid storage part is managed to be substantially constant, for example, spraying more industrial water from the spray nozzle than the amount of water lost due to the evaporation amount, etc. Can not.

  That is, when the liquid level of the absorbing liquid becomes high in the absorbing liquid storage part, the part below the liquid level at the lower end of the sparger pipe becomes long, and a large pressure is required to eject the exhaust gas into the absorbing liquid. End up. In addition, when the liquid level of the absorbing liquid is lowered, the portion below the liquid level at the lower end of the sparger pipe is shortened, and the gas-liquid contact between the exhaust gas and the absorbing liquid may be insufficient, leading to a decrease in the desulfurization rate. there were. Therefore, it is necessary to keep the liquid level of the absorbent in the absorbent reservoir.

  The present invention has been made in view of the above circumstances, and provides a desulfurization apparatus and an exhaust gas cooling method in which a gas dispersion pipe is not clogged even when an exhaust liquid is circulated and cooled to exhaust gas. Objective.

In order to achieve the object, the desulfurization apparatus according to claim 1 includes an absorption liquid storage part in which an absorption liquid for desulfurization that absorbs sulfur oxide from exhaust gas is stored, and the absorption on the absorption liquid storage part. An exhaust gas introduction part that is provided separately from the liquid storage part and into which the exhaust gas is introduced, and extends from the bottom of the exhaust gas introduction part into the absorption liquid of the absorption liquid storage part, and the introduced exhaust gas is supplied to the absorption liquid storage part A plurality of gas dispersion pipes to be jetted and dispersed in the absorption liquid, and the exhaust liquid storage section, and separated from the exhaust gas introduction section and provided with desulfurized exhaust gas discharged from the absorption liquid. A desulfurization apparatus comprising: an exhaust gas deriving unit for deriving; and a gas riser that allows the upper space above the liquid level of the absorbing liquid in the absorption liquid storage unit and the exhaust gas deriving unit to communicate with each other through the exhaust gas introducing unit. And
An absorption liquid spray nozzle that is provided above the gas dispersion pipe in the exhaust gas introduction section and continuously sprays the absorption liquid on the gas dispersion pipe side in order to cool the exhaust gas; and the absorption liquid spray nozzle An absorbent supply means for supplying the absorbent in the absorbent reservoir,
The gas dispersion pipes are distributed and arranged at the bottom of the exhaust gas introduction part;
Each absorption liquid spray nozzle is arranged in correspondence with the arrangement of the gas dispersion pipe so that substantially all of the gas dispersion pipe falls within the range in which the absorption range of the absorption liquid of each absorption liquid spray nozzle is combined,
When the gypsum adhering to the surface of the gas riser penetrating the gas introduction part falls on the gas dispersion pipe, each of the absorption liquid supply means is allowed to flow the gypsum without clogging the gas dispersion pipe. The liquid amount of the absorbing liquid supplied and sprayed to the absorbing liquid spray nozzle is 0.5 to 3.0 l / Nm ³ in terms of the liquid gas ratio to the amount of exhaust gas introduced ,
And, characterized by a spray pressure in the spray nozzles for each absorbing solution and 0.5~2.0kgf / cm ^2.

According to a second aspect of the present invention, the desulfurization apparatus according to the first aspect of the invention is introduced by spraying makeup water for replenishing the absorption liquid storage section into a duct for introducing the exhaust gas from the outside into the exhaust gas introduction section. A replenishment water spray cooling mechanism for cooling the exhaust gas is provided.

According to a third aspect of the present invention, there is provided a method for cooling an exhaust gas, wherein an absorption liquid storage part storing an absorption liquid for desulfurization that absorbs sulfur oxide from the exhaust gas is separated from the absorption liquid storage part on the absorption liquid storage part. An exhaust gas introduction part into which the exhaust gas is introduced and the bottom part of the exhaust gas introduction part extending into the absorption liquid of the absorption liquid storage part, and the introduced exhaust gas is jetted into the absorption liquid of the absorption liquid storage part A plurality of gas dispersion pipes to be dispersed, and an exhaust gas derivation unit that communicates with the absorption liquid storage unit and that is provided separately from the exhaust gas introduction unit, and that derives desulfurized exhaust gas discharged from the absorption liquid; An exhaust gas cooling method performed in a desulfurization apparatus including a gas riser that connects an upper space above the liquid level of the absorption liquid in the absorption liquid storage section and the exhaust gas outlet section through the exhaust gas introduction section. There,
The desulfurization device is provided above the gas dispersion pipe in the exhaust gas introduction unit, and sprays the absorption liquid to cool the exhaust gas, and stores the absorption liquid in the absorption liquid spray nozzle. And an absorption liquid supply means for supplying the absorption liquid of the portion , and in the desulfurization apparatus, the gas dispersion pipe is arranged dispersedly at the bottom of the exhaust gas introduction section, and the absorption nozzles absorb the absorption liquid. Each absorbing liquid spray nozzle is arranged corresponding to the arrangement of the gas dispersion pipe so that substantially all of the gas dispersion pipe falls within the range in which the spray range of the liquid is combined,
The absorption liquid is continuously sprayed from the absorption liquid spray nozzle to the gas dispersion pipe side,
In this spraying, when the gypsum adhering to the surface of the gas riser penetrating the gas introduction part falls on the gas dispersion pipe, the absorbent liquid is used to flow the gypsum without clogging the gas dispersion pipe. The liquid amount of the absorbing liquid supplied from the supply means to each absorbing liquid spray nozzle and sprayed is 0.5 to 3.0 l / Nm ³ in terms of the liquid gas ratio to the amount of exhaust gas introduced ,
And, characterized by a spray pressure in the spray nozzles for each absorbing solution and 0.5~2.0kgf / cm ^2.

The exhaust gas cooling method according to claim 4 is the invention according to claim 3 , wherein a supply water spray cooling mechanism is provided in a duct for introducing exhaust gas from the outside to the exhaust gas introduction part of the desulfurization device,
The replenishing water spray cooling mechanism cools the exhaust gas introduced by spraying replenishing water for replenishing the absorption liquid storage section.

In the first and third aspects of the invention, the spray nozzle for cooling the exhaust gas is disposed not above the inlet duct portion for introducing the exhaust gas into the exhaust gas introduction portion but above the gas dispersion pipe in the gas introduction portion. Has been. The spray nozzle is sprayed with an absorption liquid to be circulated.
Therefore, even if the amount of liquid sprayed for circulation is increased, there is almost no effect on the liquid level of the liquid absorption in the absorption liquid storage part. Therefore, it is possible to spray the absorbing liquid.

As a result, the exhaust gas is reliably humidified and cooled.
Further, since the absorbing liquid is sprayed on the gas dispersion pipe portion, the communicating portion (for example, the outer surface of the gas riser) between the absorbing liquid storage portion and the exhaust gas outlet portion is larger than the case where the absorbing liquid is sprayed on the inlet duct portion. Gypsum adhesion can be reduced.

  In addition, due to continuous use for a long time, gypsum adheres to the gas riser, and the gypsum thickens and falls into the gas dispersion pipe part in a lump state to block the top opening of the gas dispersion pipe or clog the inside of the gas dispersion pipe Even if it is in a wet state, the absorption liquid is always sprayed continuously toward the gas dispersion tube with a sufficient amount of liquid, so it is possible to wash even plastered gypsum, It is possible to prevent the gas dispersion pipe from being clogged and causing pressure loss.

Moreover , the absorption liquid is sprayed on almost all gas dispersion pipes, but it is sufficient that the liquid volume of the sprayed absorption liquid is 0.5 to 3.0 l / Nm3 in terms of the liquid gas ratio to the amount of exhaust gas introduced. It is possible to increase the cooling of exhaust gas with a small amount of liquid, to wash off clogging of gas dispersion pipes with gypsum, and to prevent the cost of power related to the circulation of absorption liquid from increasing. Can do.
At this time, by setting the spray pressure at the spray nozzle for absorbing liquid to 0.5 to 2.0 kgf / cm 2 (which is a gauge pressure), the absorbing liquid is surely sprayed as a fine droplet within a predetermined range. Thus, the exhaust gas can be cooled and humidified and gypsum can be removed from the gas dispersion pipe, and the cost of power required for circulating the absorbing liquid can be prevented from increasing.

In the invention according to claim 2 and claim 4 , the exhaust gas introduced by spraying the replenishment water for replenishing the absorption liquid storage portion into the duct for introducing the exhaust gas from the outside to the exhaust gas introduction portion is cooled. Therefore, the temperature of the exhaust gas before coming into contact with the liquid sprayed by the above-described absorbing liquid spray nozzle can be reduced, and the temperature of the portion where the exhaust gas is introduced from the duct can be prevented from becoming too high. .
In other words, the absorption liquid sprayed from the absorption liquid spray nozzle sufficiently cools the exhaust gas at a position slightly above the gas dispersion pipe of the exhaust gas introduction section, but in the portion above it, the cooling is insufficient. There is a possibility that the temperature of the upper part of the exhaust gas introduction part can be surely kept within an allowable range by cooling the duct part. In addition, although the liquid quantity which can be sprayed decreases by using replenishment water for cooling, it can suppress that gypsum becomes a lump in an exhaust gas introduction part like the past.

  According to the present invention, in a desulfurization apparatus that uses an absorption liquid containing a large amount of gypsum particles and ejects exhaust gas into the absorption liquid through a gas dispersion pipe, the absorption liquid is used to cool the exhaust gas. It is possible to prevent the gas dispersion pipe from being clogged with gypsum.

It is the schematic which shows the desulfurization apparatus which concerns on embodiment of this invention. It is the schematic which shows the conventional desulfurization apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing a desulfurization apparatus according to an embodiment of the present invention.
The desulfurization apparatus of this example is characterized by the exhaust gas cooling mechanism and cooling method, and the other configurations and functions are the same as those of the conventional configuration and functions described above. Therefore, in the following, the features of this embodiment will be described. Mainly mentioned, the other parts will be simply described with the same reference numerals as in FIG.

As shown in FIG. 1, the inside of the absorption tower of the desulfurization apparatus is divided into upper and lower three layers by providing decks 2 and 3 in two upper and lower stages, as in the conventional desulfurization apparatus. The absorption liquid storage unit 4 is provided. Further, an exhaust gas introduction unit 6 is provided between the lower deck 2 and the upper deck 3, and an upper side of the upper deck 3 is an exhaust gas deriving unit 8.
In addition, an inlet duct 5 is connected to the exhaust gas introduction part 6, and an outlet duct 7 is connected to the exhaust gas outlet part 8.

The lower deck 2 has an upper end projecting from the exhaust gas introduction section 6 on the lower deck 2, and a lower end is below the liquid level of the absorbent K in the absorbent storage section 4 below the lower deck 2. A sparger pipe 9 extending up to is provided.
In addition, a gas riser 10 is provided from the lower surface side of the lower deck 2 to the upper surface side of the upper deck 3. It is communicated.
Although not shown in the figure, as in the prior art, a mechanism for supplying oxygen to the absorbent, a mechanism for supplying the absorbent, and a solid for extracting the absorbent and separating solids such as gypsum from the absorbent. A liquid separation mechanism is provided.

  In the desulfurization apparatus of this example, a replenishment water spray cooling mechanism 21 that sprays replenishment water and cools the exhaust gas introduced from the outside through the entrance duct 5 is provided on the inlet duct 5 of the exhaust gas introduction unit 6. . The makeup water spray cooling mechanism 21 is supplied with, for example, industrial water or the filtrate separated by the above-described solid-liquid separation as makeup water, and is sprayed from the makeup water spray nozzle 22. The amount of liquid that can be sprayed from the makeup water spray cooling mechanism 21 is limited in order to maintain the liquid level of the absorbing liquid in the absorbing liquid storage unit 4 substantially constant, but the exhaust gas temperature has heat resistance as a resin. It is possible to make the temperature lower than the temperature that affects the member made of FRP or the flame lining inside the absorption tower.

Further, in this example, there is no gas cooling part for cooling the exhaust gas by spraying the conventional absorption liquid on the inlet duct 5, and no absorption liquid is used for cooling in the inlet duct 5. In the duct 5, only makeup water is used for cooling the exhaust gas.
In the exhaust gas treatment apparatus, heat exchange is performed between the introduced exhaust gas and the derived exhaust gas to reduce the temperature of the introduced exhaust gas and increase the temperature of the treated exhaust gas to be derived. When the temperature of the exhaust gas to be introduced can be lowered to a level that does not affect the FRP or flake lining members in the absorption tower by providing the heat exchanger Further, a configuration in which the makeup water spray cooling mechanism 21 is not provided may be employed.

As described above, the amount of water that can be introduced into the absorption tower is limited in order to maintain the liquid level of the absorption liquid in the absorption liquid storage unit 4 to be substantially constant. By doing so, it becomes possible to use makeup water for other purposes.
For example, the outlet duct 7 is provided with a mist eliminator to remove minute droplets accompanying the desulfurized exhaust gas. However, the use of makeup water for cleaning the mist eliminator prevents the mist eliminator from becoming dirty. It is possible to prevent and reduce the work required for maintenance.

Here, in the lower deck 2 that is the bottom of the exhaust gas introduction section 6, a plurality of sparger pipes 9 are arranged in the main section that is substantially the entire lower deck 2 vertically and horizontally (front and rear, left and right), and arranged at substantially equal intervals. As a whole, a large number of sparger pipes 9 are arranged. For example, 20 or more sparger pipes 9 are arranged within a range of about 1 m ² , and depending on the amount of exhaust gas and the area of the lower deck 2 corresponding thereto, several hundred or more sparger pipes 9 as a whole are arranged in the lower deck. 2 are distributed substantially evenly.

  Moreover, the gas riser 10 is arrange | positioned for every sparger pipe 9 for every predetermined number. The gas riser 10 is formed to have a larger cross-sectional area than the sparger pipe 9, and the sparger pipe 9 cannot be arranged at the arrangement position of the gas riser 10. The vertical and horizontal intervals are wide.

However, the number of sparger pipes 9 arranged for each predetermined area (per unit area) is substantially the same, and the same number of sparger pipes 9 is arranged for each predetermined area.
Note that the sparger pipe 9 may be arranged in any way as long as the exhaust gas can be efficiently introduced into the absorption liquid in the absorption liquid storage section 4 from the exhaust gas introduction section 6 and dispersed. Within the range where the two sparger pipes 9 are arranged, approximately the same number of sparger pipes 9 are arranged for each predetermined area.

  Further, a plurality of gas risers 10 are arranged side by side in the vertical and horizontal directions, and approximately the same number of gas risers 10 are arranged for each predetermined area. It is running low. The gas riser 10 is configured to remove the exhaust gas that has been smoothly desulfurized without causing a large pressure loss from the gas layer portion above the liquid level of the absorption liquid in the absorption liquid storage section 4 to the exhaust gas discharge section 8 above the upper deck 3. If it can flow, the number and arrangement can be freely set.

  As described above, the exhaust gas introduction part 6 in which the sparger pipe 9 and the gas riser 10 are arranged is introduced into the exhaust gas introduction part 6 using an absorption liquid that is circulated between the absorption liquid storage part 4 and used. An exhaust gas cooling mechanism for cooling the exhaust gas is provided.

  The exhaust gas cooling mechanism includes an absorption liquid spray nozzle 31 disposed above a sparger pipe 9 disposed in a state where the upper end portion projects from the lower deck 2 serving as the bottom of the exhaust gas introduction section 6, and the absorption liquid spray. Absorption liquid 32 for allowing the absorption liquid to flow out to the nozzle 31 and the absorption liquid that sucks the absorption liquid from the absorption liquid reservoir 4 and supplies the absorption liquid to the spray nozzle 31 via the absorption liquid pipe 32. And a pump 33.

The absorption liquid pipe 32 and the absorption liquid pump 33 serve as absorption liquid supply means for supplying the absorption liquid in the absorption liquid storage section 4 to the absorption liquid spray nozzle 31.
The absorbing liquid spray nozzle 31 sprays the absorbing liquid as fine droplets so as to spread in a substantially conical shape, and has a substantially circular shape having a diameter corresponding to the distance from the absorbing liquid spray nozzle 31. The absorbent is sprayed onto the area.

The absorbing liquid spray nozzles 31 are distributed and arranged on the lower deck 2 so that the liquid droplets of the absorbing liquid sprayed directly on almost all the sparger pipes 9 arranged on the lower deck 2 are hit. .
In this example, a plurality of spray nozzles 31 for absorbing liquid are arranged side by side at substantially equal intervals in the vertical and horizontal directions corresponding to the arrangement of the sparger pipe 9.

Further, the adsorbing liquid spray nozzles 31 adjacent to each other are arranged at a distance closer to the radius of the spraying range corresponding to the distance from the height position of the absorbing liquid spray nozzle 31 to the height position of the sparger pipe 9. .
In other words, the absorption liquid spray nozzles 31 arranged above the sparger pipe 9 are configured such that a part of the spray range of the adjacent absorption liquid spray nozzles 31 overlaps.

As a result, within the range in which the sparger pipe 9 of the lower deck 2 is provided, most of the portion on the lower deck 2 is included in any of the spray ranges of the spray nozzle 31 for absorbing liquid, and almost all of the sparger. The pipe 9 is disposed within the spray range of the absorbing liquid spray nozzle 31.
For example, sparger pipe 9 is much arranged one by twenty within approximately 1 m ² range, as described above, Gasuraiza 10 is disposed extent one by one in a slightly larger range or than approximately 1 m ² range, spray absorption solution As with the gas riser 10, the nozzles 31 are also arranged approximately one by one in a range of about 1 m ² or a little wider than that.

  The gas riser 10 and the absorbent spray nozzle 31 are arranged side by side at substantially equal intervals in the vertical and horizontal directions. In one of the vertical and horizontal directions, the row of the gas risers 10 and the absorbent spray nozzle 31 columns are arranged so as to overlap each other, and in each vertical column, the gas risers 10 and the absorbent spray nozzles 31 are alternately arranged one by one.

  In the other of the vertical and horizontal directions, the rows of gas risers 10 and the rows of spray nozzles 31 for absorbing liquid do not overlap each other. In the rows of gas risers 10, only the gas risers 10 are arranged in a row. In the row of the absorbing liquid spray nozzles 31, only the absorbing liquid spray nozzles 31 are arranged in a line, and the rows of the gas risers 10 and the rows of the absorbing liquid spray nozzles 31 are alternately arranged.

  The absorbing liquid spray nozzle 31 is arranged at a position between the gas risers 10, and almost all the sparger pipes 9 are included in the spraying range of the absorbing liquid spray nozzle 31 as described above. If so, the arrangement of the spray nozzle 31 for absorbing liquid may be any, and it is not necessary to be arranged so as to substantially correspond to the gas riser 10 on a one-to-one basis.

  Further, since the absorbent liquid spray nozzle 31 is a gypsum slurry, it is necessary to use an absorbent liquid that is highly wear-resistant and difficult to clog. For example, a ceramic spray nozzle or a metal spray nozzle It is preferable to use a spray nozzle having a double structure in which the inner side is ceramic. Further, it is preferable to use a spray nozzle having a relatively large pore diameter (diameter of the narrowest inner diameter) for the slurry. Moreover, it is preferable to use the nozzle whose outer diameter of the external thread part for a connection or internal diameter of an internal thread part is 25 mm-40 mm as a size of a spray nozzle. If the size is smaller than 25 mm, the passage diameter of the spray nozzle becomes small and there is a risk of clogging with gypsum. If the size is 40 mm or more, the number of spray nozzles decreases, so that the absorbing liquid is not sufficiently dispersed. There is a possibility that cooling of the exhaust gas may be insufficient, and a cleaning ability described later may be insufficient.

The above-described absorbent liquid pipes 32 are, for example, arranged on the lower deck 2 at a position higher than the sparger pipe 9 and in parallel with each other at equal intervals, that is, in a stripe shape.
The absorbent liquid spray nozzle 31 is attached to the absorbent liquid pipe 32. As described above, the absorbing liquid spray nozzles 31 are attached to the absorbing liquid pipes 32 arranged in stripes at substantially equal intervals, and the absorbing liquid spray nozzles 31 are attached to the attaching parts.

  Further, the attachment portion may be a branch pipe that extends at right angles along the substantially horizontal direction from the absorbent liquid pipe 32 arranged as described above. Moreover, the attachment part as a branch pipe is good also as what extends in the right-and-left both directions from the piping 32 for absorption liquids, and good also as what extends to either one of right and left. Further, when the attachment portion extends from the absorbent liquid pipe 32 in both the left and right directions, it may extend from substantially the same position to the left and right, or may alternately extend from different positions.

Moreover, it is good also as a structure where the gas riser 10 supports the absorption liquid pipe 32 and the branch tubular attachment part, or a structure where the gas riser 10 supports the absorption liquid pipe 10 in an auxiliary manner.
In the desulfurization apparatus (exhaust gas cooling mechanism) as described above, the liquid gas with respect to the amount of exhaust gas introduced from the absorbing liquid supply means to the absorbing liquid spray nozzles 31 to be introduced and sprayed. The ratio (volume ratio) is 0.5 to 3.0 l / Nm ³ .

Here, if the liquid-gas ratio between the total amount of the absorbing liquid sprayed from all the absorbing liquid spray nozzles 31 and the amount of exhaust gas introduced into the desulfurization apparatus is less than 0.5 / Nm ³ , for example, each absorbing liquid The spray pressure in the spray nozzle 31 for use will become lower than the range mentioned later. Therefore, in order to set the spray pressure of each spray nozzle 31 for absorbing liquid within the range described later, the number of spray nozzles 31 for absorbing liquid that can be arranged is reduced.
Basically, the number and arrangement of the sparger pipes 9 and the area of the lower deck 2 (area where the sparger pipes are arranged) are determined based on the amount of exhaust gas to be introduced. The number of the spray nozzles 31 for absorbing liquid per unit area or per sparger pipe 9 is determined by the ratio of the liquid gas to the amount of exhaust gas.

Here, the absorbing liquid sprayed from the sparger pipe 9 is not only used for cooling the exhaust gas, but also the sparger pipe 9 when gypsum adhering to the surface of the gas riser 10 falls as a lump as will be described later. It is designed to prevent clogging.
That is, since the absorbing liquid is sprayed from the sparger pipe 9, there is a possibility that gypsum adheres to the inner wall surface of the gas riser 10 or the exhaust gas introduction part, and the adhering gypsum with the elapse of a long period of time is less There is a risk that it will become thick and fall as usual.

In this case, since the absorbing liquid is continuously sprayed from the absorbing liquid spray nozzle 31 on the sparger pipe 9, it becomes possible to wash away the gypsum that has become a mass, and the clogging of the sparger pipe is eliminated. be able to.
However, if the spray pressure of the absorbing liquid from the sparger pipe 9 is too low or the number of arrangements per unit area of the sparger pipe 9 is too small, it may be difficult to wash away the plaster that clogs the sparger pipe 9. . In particular, when the amount of the absorbing liquid sprayed varies greatly depending on the sparger pipe 9, the sparger pipe with the relatively small amount of the absorbing liquid sprayed may remain clogged.

Therefore, it is necessary that the liquid amount of the absorbing liquid sprayed as described above is 0.5 l / Nm ³ or more in terms of the liquid gas ratio with respect to the amount of exhaust gas introduced.
Further, when the liquid amount of the absorbed liquid to be sprayed is larger than 3.0 l / Nm ³ in terms of the liquid gas ratio with respect to the amount of exhaust gas introduced, the liquid amount increases more than necessary and the absorption liquid pump 33 is applied. The power cost increases, resulting in inefficiency and cost increase.

In order to operate the desulfurization apparatus more efficiently and at low cost, it is preferably 2.0 l / Nm ³ or less, and more preferably 1.0 l / Nm ³ or less.
In this example, the spray pressure in each spray nozzle 31 for absorbing liquid is set to 0.5 to 2.0 kgf / cm ² .
If the spray pressure is less than 0.5 kgf / cm ² , spraying as a spray is not performed sufficiently, and there is a risk that the sprayed droplets may be too large or the spray range may be narrowed. May be insufficient, or the above-mentioned ability to clean the dropped gypsum lump may be insufficient.

On the other hand, if the spray pressure is 2.0 kgf / cm ² or higher, the power cost of the absorbing liquid pump 33 increases due to the pressure increase, and the running cost becomes high.
In order to operate the desulfurization apparatus more efficiently and at low cost, the spray pressure is preferably set to 1.0 kgf / cm ² or less.

In the desulfurization apparatus as described above, the absorbing liquid is sprayed from the absorbing liquid spray nozzle 31 when the desulfurizing apparatus is in operation. Then, the arrangement of the absorption liquid spray nozzle 31 is set as described above, and the liquid amount of the absorption liquid supplied from the absorption liquid supply means to the respective absorption liquid spray nozzles 31 and sprayed is liquid with respect to the exhaust gas amount introduced. By setting the gas ratio to 0.5 to 3.0 l / Nm ³ and the spray pressure in the spray nozzle 31 for absorbing liquid to 0.5 to 2.0 kgf / cm ² , the exhaust gas introduction section 6 has sufficient exhaust gas. It is possible to cool with increased humidity.

Furthermore, even if the gypsum adhering to the inner wall surface of the gas riser 10 or the exhaust gas introduction unit 6 falls and clogs the sparger pipe 9, the absorbing liquid is continuously sprayed with the above-described liquid amount and spray pressure. This makes it possible to wash away the dropped plaster.
Moreover, since the spray nozzle 31 for absorption liquid is arrange | positioned so that substantially all the sparger pipes 9 may enter into the spraying range, it is possible to eliminate clogging of almost all of the sparger pipes 9 due to the plaster. It is possible to prevent an increase in the number of sparger pipes 9 that are clogged with progress.

  Further, even if the absorption liquid in the absorption liquid storage section 4 is sucked and extracted by the absorption liquid pump 33, it is sprayed again by the exhaust gas introduction section 6 and then returns to the absorption liquid storage section 4. Even if the amount of the absorbing liquid sprayed from the nozzle 31 is increased, the liquid level of the absorbing liquid in the absorbing liquid storage unit 4 does not change greatly. Therefore, as described above, the amount of liquid sufficient for cooling the exhaust gas and washing the dropped gypsum can be sprayed from the absorbing liquid spray nozzle.

  Conventionally, the spray nozzle that sprays makeup water intermittently onto the sparger pipe 9 and the gas riser 10 requires an on / off valve for intermittent operation, but the absorbent spray nozzle 31 of the present invention is in operation. Since the absorption liquid is always sprayed, the on-off valve is not required and the cost can be reduced.

K Absorbent 1 Absorber 2 Lower deck 3 Upper deck 4 Absorbent reservoir 5 Inlet duct (duct)
6 Exhaust gas introduction part 8 Exhaust gas extraction part 9 Sparger pipe (gas dispersion pipe)
31 Absorption liquid spray nozzle 32 Absorption liquid piping (absorption liquid supply means)
33 Absorption liquid pump (absorption liquid supply means)

Claims (4)

An absorption liquid storage part in which an absorption liquid for desulfurization that absorbs sulfur oxide from the exhaust gas is stored, and an exhaust gas introduction part that is provided separately from the absorption liquid storage part on the absorption liquid storage part and into which the exhaust gas is introduced A plurality of gas dispersion pipes extending from the bottom of the exhaust gas introduction part into the absorption liquid of the absorption liquid storage part, and jetting and dispersing the introduced exhaust gas into the absorption liquid of the absorption liquid storage part, An exhaust gas deriving unit that communicates with the absorption liquid storage unit and is provided separately from the exhaust gas introduction unit and derives the desulfurized exhaust gas discharged from the absorption liquid; and the liquid of the absorption liquid in the absorption liquid storage unit A desulfurization apparatus comprising a gas riser that communicates the upper space above the surface and the exhaust gas outlet through the exhaust gas inlet ,
An absorption liquid spray nozzle that is provided above the gas dispersion pipe in the exhaust gas introduction section and continuously sprays the absorption liquid on the gas dispersion pipe side in order to cool the exhaust gas; and the absorption liquid spray nozzle An absorbent supply means for supplying the absorbent in the absorbent reservoir,
The gas dispersion pipes are distributed and arranged at the bottom of the exhaust gas introduction part;
Each absorption liquid spray nozzle is arranged in correspondence with the arrangement of the gas dispersion pipe so that substantially all of the gas dispersion pipe falls within the range in which the absorption range of the absorption liquid of each absorption liquid spray nozzle is combined,
When the gypsum adhering to the surface of the gas riser penetrating the gas introduction part falls on the gas dispersion pipe, each of the absorption liquid supply means is allowed to flow the gypsum without clogging the gas dispersion pipe. The liquid amount of the absorbing liquid supplied and sprayed to the absorbing liquid spray nozzle is 0.5 to 3.0 l / Nm ³ in terms of the liquid gas ratio to the amount of exhaust gas introduced ,
And desulfurization apparatus characterized by the spray pressure at the spray nozzle for each absorbing solution and 0.5~2.0kgf / cm ^2. The exhaust gas introduction part is provided with a supplementary water spray cooling mechanism for cooling the exhaust gas introduced by spraying the supplementary water for replenishing the absorption liquid storage part into a duct for introducing the exhaust gas from the outside. The desulfurization apparatus according to claim 1 . An absorption liquid storage part in which an absorption liquid for desulfurization that absorbs sulfur oxide from the exhaust gas is stored, and an exhaust gas introduction part that is provided separately from the absorption liquid storage part on the absorption liquid storage part and into which the exhaust gas is introduced A plurality of gas dispersion pipes extending from the bottom of the exhaust gas introduction part into the absorption liquid of the absorption liquid storage part, and jetting and dispersing the introduced exhaust gas into the absorption liquid of the absorption liquid storage part, An exhaust gas deriving unit that communicates with the absorption liquid storage unit and is provided separately from the exhaust gas introduction unit and derives the desulfurized exhaust gas discharged from the absorption liquid; and the liquid of the absorption liquid in the absorption liquid storage unit An exhaust gas cooling method performed in a desulfurization apparatus comprising a gas riser that communicates the upper space above the surface and the exhaust gas outlet part through the exhaust gas introduction part ,
The desulfurization device is provided above the gas dispersion pipe in the exhaust gas introduction unit, and sprays the absorption liquid to cool the exhaust gas, and stores the absorption liquid in the absorption liquid spray nozzle. And an absorption liquid supply means for supplying the absorption liquid of the portion , and in the desulfurization apparatus, the gas dispersion pipe is arranged dispersedly at the bottom of the exhaust gas introduction section, and the absorption nozzles absorb the absorption liquid. Each absorbing liquid spray nozzle is arranged corresponding to the arrangement of the gas dispersion pipe so that substantially all of the gas dispersion pipe falls within the range in which the spray range of the liquid is combined,
The absorption liquid is continuously sprayed from the absorption liquid spray nozzle to the gas dispersion pipe side,
In this spraying, when the gypsum adhering to the surface of the gas riser penetrating the gas introduction part falls on the gas dispersion pipe, the absorbent liquid is used to flow the gypsum without clogging the gas dispersion pipe. The liquid amount of the absorbing liquid supplied from the supply means to each absorbing liquid spray nozzle and sprayed is 0.5 to 3.0 l / Nm ³ in terms of the liquid gas ratio to the amount of exhaust gas introduced ,
And exhaust gas cooling method characterized by the spray pressure and 0.5~2.0kgf / cm ² in the spray nozzle for each absorbing solution. A makeup water spray cooling mechanism is provided in a duct for introducing exhaust gas from the outside to the exhaust gas introduction part of the desulfurization apparatus,
4. The exhaust gas cooling method according to claim 3 , wherein the makeup water spray cooling mechanism cools the exhaust gas introduced by spraying makeup water for replenishing the absorption liquid reservoir. 5.

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