JPH119955A - Spray type square absorption tower for flue gas desulfurization equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spray type square absorption tower of a flue gas desulfurization device which has a low tower height, can easily arrange a spray nozzle, and can suppress generation of gas drift. SOLUTION: In an absorption tower that introduces exhaust gas and desulfurizes, an absorption tower main body 1 is formed in a box shape, and a liquid storage section 9 for storing an absorbent slurry is formed at the bottom of the box-shaped absorption tower main body 1. An absorbent spraying means 7 is provided on the upper part of the box-shaped absorption tower main body 1, and the liquid reservoir 9 of the box-shaped absorption tower main body 1 is provided.
An exhaust gas inlet 4 for introducing exhaust gas is provided at an upper portion of the exhaust gas, and an exhaust gas outlet 5 for discharging exhaust gas is provided at an upper portion of the absorbent spraying means 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption tower for desulfurizing an exhaust gas containing sulfur by spraying an alkali absorbent slurry on the exhaust gas, and more particularly to an absorption tower whose main body is formed in a box shape, that is, a square shape. .

[0002]

2. Description of the Related Art Exhaust gas generated when burning fuel such as coal contains a high concentration of sulfur, so it is necessary to introduce this into a flue gas desulfurization unit to desulfurize it and then release it to the atmosphere. is there.

FIG. 3A, FIG. 3B and FIG. 3C show a part of a conventional flue gas desulfurization apparatus 30, in which exhaust gas is introduced from below and flows upward, and an alkaline absorbent slurry (calcium carbonate) is added to the exhaust gas. ) Of the conventional absorption tower that performs desulfurization by spraying from above (Fig. 3).
A is a horizontal sectional view of the flue gas desulfurization device 30, FIG. 3B is a vertical sectional view of the flue gas desulfurization device 30, and FIG. 3C is a bird's-eye view of the flue gas desulfurization device 30).

As apparent from these figures, the tower body 21 of the conventional absorption tower is formed in a cylindrical shape (round shape).
At the bottom of the tower body 21, a liquid reservoir 29 in which the absorbent slurry is stored.
Is formed. An exhaust gas introduction duct 22 is connected to a lower portion of the tower body 21 (above the liquid reservoir 29) via an exhaust gas inlet 24, while exhaust gas is discharged to the uppermost portion of the tower body 21 via an exhaust gas outlet 25. The duct 23 is connected, and the exhaust gas introduced into the lower part of the tower main body 21 via the exhaust gas introduction duct 22 rises from below the tower main body 21 upward, and then passes through the eliminator 26 and the exhaust gas discharge duct 23. It is being discharged. The exhaust gas discharge duct 23 is supported by a frame 31.

[0005] On the upstream side of the exhaust gas introduction duct 22, various facilities (not shown) such as a boiler, a gas cooler, and a heat recovery gas gas heater are connected. On the downstream side of the exhaust gas discharge duct 23, a reheating gas gas heater (not shown) is provided. A chimney etc. is connected.

[0006] Absorber spray means 7 for spraying an absorbent slurry on the exhaust gas is installed in the upper part of the tower main body 21 (but lower than the exhaust gas discharge port 25) as shown in Fig. 3B. In the absorbent spraying means 7 and the tower body 21,
An absorbent slurry circulating means 8 for drawing out the absorbent slurry accumulated in the liquid reservoir 29 of the tower body 21 and returning it to the absorbent spraying means 7 is provided as shown. Further, an absorbent slurry supply means (not shown) for supplying the absorbent slurry into the tower main body 21 is provided, which is connected to the tower main body 21.

The liquid reservoir 29 of the tower body 21 has a liquid reservoir 29.
A gypsum separation means 11 is connected to the gypsum separation means 11 for extracting the gypsum and separating the gypsum and returning the supernatant to the liquid reservoir 29.

As apparent from FIGS. 3A and 3C, the widths of the upper (horizontal) and lower edges of the exhaust gas inlet 24 are set sufficiently smaller than the diameter of the tower body 21 and the exhaust gas introduction duct. It is configured such that the strength of the tower body 21 is not impaired even when the tower 22 is connected to the tower body 21 via the exhaust gas inlet 24. Similarly, the width of the upper and lower edges (in the horizontal direction) of the exhaust gas discharge port 25 is set sufficiently smaller than the diameter of the tower main body 21, and the exhaust gas discharge duct 23 is connected to the tower main body through the exhaust gas discharge port 25. It is configured so that the strength of the tower main body 21 is not impaired even if it is connected to the tower 21.

The fuel is burned in the boiler to generate exhaust gas. The exhaust gas passes through a gas cooler and other exhaust gas treatment equipment, and then passes through an exhaust gas introduction duct 22 through an exhaust gas inlet 2.
4 and is introduced into the lower part of the tower body 21.

The exhaust gas introduced into the lower part of the tower body 21 rises inside the tower body 21 and is sprayed with an alkaline absorbent slurry by the absorbent spraying means 7, whereby the sulfur content (SO ₂ , SO ₃₎ ) Is absorbed in gas-liquid contact with the absorbent slurry to perform desulfurization.

The desulfurized exhaust gas is discharged from an exhaust gas discharge port 25 through an exhaust gas discharge duct 23 and discharged to the atmosphere via a chimney or the like.

On the other hand, the absorbent stored in the liquid reservoir 29 of the absorption tower 21 (including the gypsum generated by the above desulfurization reaction)
Is extracted by the absorbent slurry circulation means 8 and returned to the absorbent spray means 7 again to be sprayed. Further, the gypsum separating means 11 appropriately removes the liquid from the liquid reservoir 29, separates and collects the gypsum, returns the supernatant liquid to the liquid reservoir 29, and thereafter repeats the above process.
Further, the absorbent slurry is appropriately supplied into the tower main body 21 by the absorbent slurry supply means.

[0013]

In the case of a cylindrical (round) absorption tower as described above, the connecting portion between the exhaust gas introduction duct and the exhaust gas discharge duct and the tower body (that is, the exhaust gas inlet and the exhaust gas outlet described above). ) If the width of the upper edge and the lower edge is to be made wider along the peripheral wall of the tower body, the section of the tower body at that portion will not be circular and the strength will decrease,
The widths of the upper and lower edges of the exhaust gas inlet and exhaust gas outlet cannot be made wide (along the peripheral wall of the tower body).

That is, in the case of a round absorption tower, the width of the exhaust gas inlet and the exhaust gas outlet cannot be made wider than a certain ratio with respect to the diameter of the absorption tower. Therefore, if the cross-sectional areas of the exhaust gas introduction duct and the exhaust gas discharge duct are to be maintained at a certain level or more, the heights of the exhaust gas introduction port and the exhaust gas exhaust port in the axial direction will inevitably increase.

If the height of the exhaust gas inlet and the exhaust gas outlet is large, the height of the absorption tower is increased, and the lift distance of the slurry circulation pump is increased, which causes a problem that the load on the pump is large.

Further, when the absorption tower is high, the structure (frame) supporting ducts and the like connected to the absorption tower also becomes high, and there is a problem that the weight and cost of the entire apparatus are increased.

Furthermore, in the case of the conventional round absorption tower, the gas arrival distance (the distance from the gas inlet side to the opposite side (tower main body) side) is not uniform, and the gas arrival distance is long at the center. There is a problem that gas drift is likely to occur (see FIG. 2B) because it becomes shorter toward the end.

Further, since the horizontal cross section of the tower body is circular,
In order to spray the absorbent slurry uniformly in the tower body,
There was a problem that the arrangement of the absorbent spraying means (spray nozzle) had to be individually considered each time the tower diameter changed.

Therefore, an object of the present invention is to improve a conventional circular configuration to reduce the tower height, facilitate the arrangement of spray nozzles, and suppress the occurrence of gas drift. It is to provide an absorption tower.

[0020]

In order to achieve the above object, an invention according to claim 1 is directed to an absorption tower for introducing exhaust gas and desulfurizing, wherein the absorption tower main body is formed in a box shape, A liquid reservoir for storing the absorbent slurry is formed at the bottom of the tower main body, and an absorbent spraying means is provided at the top of the box-shaped absorption tower main body, and at the top of the liquid reservoir of the box-shaped absorption tower main body. An exhaust gas inlet for introducing exhaust gas is provided by providing an exhaust gas outlet for discharging exhaust gas above the absorbent spraying means.

According to a second aspect of the present invention, the exhaust gas inlet and the exhaust gas outlet are formed flat.

[0022]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1A, FIG. 1B and FIG. 1C show a part of a flue gas desulfurization apparatus 20 which introduces exhaust gas from below and flows it upward, and adds an alkaline absorbent slurry (such as calcium carbonate) to the exhaust gas. Of the absorption tower according to the present invention, in which sulfur is sprayed from above to perform desulfurization, is shown in FIG. 1A.
Is a horizontal sectional view of the flue gas desulfurization device 20, FIG. 1B is a vertical sectional view of the flue gas desulfurization device 20, and FIG. 1C is a bird's-eye view of the flue gas desulfurization device 20).

As apparent from these figures, the tower main body 1 of the absorption tower of the present invention is formed in a box shape (square shape). At the bottom of the tower body 1 is formed a liquid reservoir 9 for storing the absorbent slurry. Lower part of the tower body 1 (but above the liquid reservoir 9)
An exhaust gas introduction duct 2 is connected to the tower via an exhaust gas introduction port 4, while an exhaust gas discharge duct 3 is connected to an uppermost portion of the tower main body 1 via an exhaust gas exhaust port 5, and the tower is connected to the tower via the exhaust gas introduction duct 2. After the exhaust gas introduced into the lower part of the main body 1 rises upward from below in the tower main body 1, it is discharged through the eliminator 6 and the exhaust gas discharge duct 3. The discharge duct 3 is supported by the frame 10.

In the present embodiment, the tower body 1
It is desirable to provide a suitable reinforcing means (not shown) for supplementing the strength.

On the upstream side of the exhaust gas introduction duct 2, various facilities (not shown) such as a boiler, a gas cooler, and a heat recovery gas gas heater are connected. On the downstream side of the exhaust gas discharge duct 3, a reheating gas heater (not shown) A chimney etc. is connected.

Absorber spraying means 7 for spraying an absorbent slurry on the exhaust gas is installed in the upper part of the tower main body 1 (but lower than the exhaust gas discharge port 5) as shown in FIG. 1B. You. In the absorbent spraying means 7 and the tower body 1,
Further, an absorbent slurry circulating means 8 for drawing out the absorbent slurry accumulated in the liquid reservoir 9 of the tower main body 1 and returning it to the absorbent spraying means 7 is provided as shown. An absorbent slurry supply means (not shown) for supplying the absorbent slurry into the tower main body 1 is installed in connection with the tower main body 1.

A gypsum separation means 11 is connected to the liquid reservoir 9 of the tower body 1 for extracting liquid from the liquid reservoir 9 and separating gypsum to return the supernatant liquid to the liquid reservoir 9.

As can be seen from FIGS. 1A and 1C, the upper edge and the lower edge of the exhaust gas inlet 4 extending in the horizontal direction are both wide along the flat side wall of the tower body 1. The upper edge and the lower edge of the exhaust gas discharge port 5 extending in the horizontal direction are both wide along the flat side wall of the tower body 1.

In the present invention, the exhaust gas inlet 4 and the exhaust gas outlet 5, that is, the connection between the exhaust gas introduction duct 2 and the exhaust gas discharge duct 3 and the tower main body 1, and the upper edge in the horizontal direction, Since the lower edge can be configured to be wide (in the case of a square type, the tower body 1 is reinforced as described above, so that there is no danger of losing the strength even with this configuration). Only the height of the exhaust gas inlet 4 and the exhaust gas outlet 5 can be reduced.

That is, the exhaust gas inlet 4 and the exhaust gas outlet 5 can be formed in a horizontally long (flat) shape. Therefore, the height of the tower body 1 is reduced by the reduced duct height.
1 (see FIGS. 1B and 3B.
Although the tower body 1 is lower than the conventional tower body 21,
The flue distance from the exhaust gas inlet 4 to the exhaust gas outlet 5 is the same in both cases). As a result, the frame 10 in the present embodiment is replaced with a frame 31 (FIG.
Reference).

The fuel is burned in the boiler to generate exhaust gas. The exhaust gas passes through a gas cooler and other exhaust gas treatment equipment, and is introduced into the lower part of the tower body 1 from an exhaust gas inlet 4 through an exhaust gas introduction duct 2.

The exhaust gas introduced into the lower part of the tower main body 1 rises in the tower main body 1 and is sprayed with an alkaline absorbent slurry by the absorbent spraying means 7, whereby the sulfur content (SO ₂ , SO ₃₎ ) Is absorbed in gas-liquid contact with the absorbent slurry to perform desulfurization.

The desulfurized exhaust gas is discharged from the exhaust gas discharge port 5 through the exhaust gas discharge duct 3 and released to the atmosphere via a chimney or the like.

On the other hand, the absorbing liquid (including the gypsum generated by the desulfurization reaction) stored in the liquid storage section 9 of the absorption tower 1 is
After being appropriately extracted by the absorbent slurry circulation means 8 to separate gypsum, the gypsum is returned to the absorbent spraying means 7 and sprayed again. From the liquid reservoir 9, the slurry liquid is appropriately extracted by the gypsum separating means 11, and the gypsum is separated and collected, and the supernatant liquid is returned to the liquid reservoir 9, and the above steps are repeated. Also, by means of the absorbent slurry supply means,
An absorbent slurry is appropriately supplied into the tower body 1.

In the tower main body 1 of the absorption tower of the present invention, the horizontal cross section is rectangular, and therefore, the gas reach when exhaust gas is introduced into the tower main body 1 from the exhaust gas inlet 4 (the exhaust gas inlet 4 The distance from the side to the opposite side (to the side of the tower body 1) is uniform, so that the gas absorption is greater than in the conventional absorption tower 21 (the gas reach distance is different between the center and the end of the absorption tower 21). The drift is reduced (see FIGS. 2A and 2B).

Incidentally, the gas drift degree in the horizontal section X (see FIG. 2A) immediately above the exhaust gas inlet 4 of the rectangular absorption tower 1 of the present invention is about 11%, while the conventional round absorption tower is The horizontal section Y just above the exhaust gas inlet 24 of FIG.
The cross-section corresponding to the horizontal cross-section X (see FIG. 2B) is about 15%.

Further, since the horizontal cross section of the tower main body 1 of the absorption tower of the present invention is formed in a rectangular shape, an optimum absorbent spray (spray nozzle) means for uniformly spraying the absorbent slurry in the tower main body 1 is provided. 7 can be easily determined, and the same (optimum) spray nozzle arrangement can always be applied even when the tower diameter, that is, the size of the tower is changed. (On the other hand, in the conventional round absorption tower 21, as described above, , Absorbent spraying means 7
Must be individually considered each time the diameter of the absorption tower 21 changes).

In summary, according to the present invention, the connecting portions between the exhaust gas introduction duct and the exhaust duct and the rectangular tower main body, that is, the ducts near the exhaust gas inlet and the exhaust gas outlet, can be made flat. The overall height can be significantly reduced.

As a result, the lifting distance of the slurry circulation pump is shortened, the load on the pump is reduced, and the structure (frame) for supporting the duct and the like connected to the absorption tower can be configured low, and the weight and cost of the entire apparatus can be reduced. Can be saved.

In the present invention, the horizontal cross section of the tower body is rectangular, and therefore, the gas reach distance when exhaust gas is introduced from the exhaust gas inlet into the tower body (from the exhaust gas inlet side to the opposite side of the tower). ) Becomes uniform, so that the gas drift is reduced as compared with the conventional absorption tower in which the gas arrival distance is different between the center part and the end part of the tower, so that improvement in desulfurization efficiency can be expected.

Since the horizontal cross section of the tower body is rectangular, the optimum spray nozzle arrangement for uniformly spraying the absorbent slurry can be easily determined. (Optimal) Since the spray nozzle arrangement can be applied, it is easier to standardize the spray nozzle arrangement than the conventional absorption tower.

[0043]

In summary, the absorption tower of the flue gas desulfurization apparatus according to the present invention has the following excellent effects.

(1) Since the width of the connecting portion between the exhaust gas introduction duct and the exhaust duct and the rectangular tower body can be widened, the ducts near the exhaust gas introduction port and the exhaust gas exhaust port can be made flat. The overall height can be significantly reduced.
As a result, the structure (frame) that supports the duct and the like connected to the absorption tower can be configured low, and the weight and cost of the entire apparatus can be reduced.

(2) The horizontal cross section of the tower body is rectangular,
Therefore, the gas reach when the exhaust gas is introduced from the exhaust gas inlet into the tower body (the distance from the exhaust gas inlet side to the opposite side of the tower) is uniform, so that the gas reach distance is equal to the center of the tower and the end of the tower. The drift of gas is reduced as compared with the conventional absorption tower different in the section and the desulfurization rate is improved.

(3) Since the horizontal cross section of the tower body is rectangular, the optimum spray nozzle arrangement for uniformly spraying the absorbent slurry can be easily determined, and the same is always used even when the size of the tower changes. (Optimal) Since the spray nozzle arrangement can be applied, it is easier to standardize the spray nozzle arrangement than the conventional absorption tower.

[Brief description of the drawings]

FIG. 1A is a horizontal sectional view of a rectangular absorption tower (part of a flue gas desulfurization apparatus) of the present invention.

FIG. 1B is a vertical sectional view of the absorption tower of FIG. 1A.

FIG. 1C is a bird's-eye view of the absorption tower of FIG. 1A.

FIG. 2A is a view showing a result of a gas flow simulation in the rectangular absorption tower of the present invention.

FIG. 2B is a view showing a result of a gas flow simulation in a conventional round absorption tower.

FIG. 3A is a horizontal sectional view of a conventional round absorption tower (part of a flue gas desulfurization device).

FIG. 3B is a vertical sectional view of the absorption tower of FIG. 3A.

FIG. 3C is a bird's eye view of the absorption tower of FIG. 3A.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Absorption tower main body 4 Exhaust gas introduction port 5 Exhaust gas exhaust port 7 Absorbent spray means 9 Liquid reservoir

Claims (2)

[Claims] 1. An absorption tower for introducing and desulfurizing exhaust gas, wherein an absorption tower main body is formed in a box shape, and a liquid reservoir for storing an absorbent slurry is formed at a bottom of the box-shaped absorption tower main body. Absorbent spray means is provided on the upper part of the box-shaped absorption tower main body, an exhaust gas inlet for introducing exhaust gas into the upper part of the liquid storage part of the box-shaped absorber main body, and exhaust gas is provided on the upper part of the absorbent spray means. A spray-type square absorption tower of a flue gas desulfurization apparatus for introducing and desulfurizing exhaust gas, characterized by having an exhaust gas discharge port for discharging. 2. A spray type square absorption tower for a flue gas desulfurization apparatus according to claim 1, wherein said exhaust gas inlet and said exhaust gas outlet are flat.