JP3978813B2 - Spray type square absorption tower of flue gas desulfurization equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an absorption tower for spraying an alkali absorbent slurry to exhaust gas containing sulfur to desulfurize the gas, and more particularly to an absorption tower having a box body, that is, a square shape.
[0002]
[Prior art]
Since the exhaust gas generated when burning fuel such as coal contains a high concentration of sulfur, it must be introduced into a flue gas desulfurization device and desulfurized before being released into the atmosphere.
[0003]
3A, 3B, and 3C show a part of the conventional flue gas desulfurization apparatus 30. The exhaust gas is introduced from below and flows upward, and an alkaline absorbent slurry (such as calcium carbonate) is supplied to the exhaust gas. A tower body 21 of a conventional absorption tower that performs desulfurization by spraying from above is shown (FIG. 3A 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 apparatus 30).
[0004]
As is clear from these figures, the tower body 21 of the conventional absorption tower is formed in a cylindrical shape (round shape). A liquid reservoir 29 is formed at the bottom of the tower body 21 to store the absorbent slurry. An exhaust gas introduction duct 22 is connected to the lower part of the tower main body 21 (but above the liquid reservoir 29) via the exhaust gas inlet 24, while exhaust gas is discharged to the uppermost part of the tower main body 21 via the exhaust gas outlet 25. After the duct 23 is connected and the exhaust gas introduced into the lower portion of the tower main body 21 through the exhaust gas introduction duct 22 rises upward from below in the tower main body 21, the exhaust gas is introduced through the eliminator 26 and the exhaust gas discharge duct 23. It is supposed to be discharged. The exhaust gas discharge duct 23 is supported by a frame 31.
[0005]
Various equipments (not shown) such as a boiler, a gas cooler, and a heat recovery gas gas heater are connected to the upstream side of the exhaust gas introduction duct 22, while a reheating gas gas heater, a chimney, etc. (not shown) are connected to the downstream side of the exhaust gas discharge duct 23. Connected.
[0006]
In the tower main body 21, an absorbent spraying means 7 for spraying an absorbent slurry to the exhaust gas is installed in the upper part (but below the exhaust gas outlet 25) as shown in FIG. 3B. As shown in the figure, the absorbent spray means 7 and the tower body 21 are provided with an absorbent slurry circulating means 8 for pumping the absorbent slurry collected in the liquid reservoir 29 of the tower body 21 and returning it to the absorbent spray means 7. It is done. In addition, an absorbent slurry supply means (not shown) that is connected to the tower body 21 and supplies the absorbent slurry into the tower body 21 is installed.
[0007]
Connected to the liquid reservoir 29 of the tower body 21 is a gypsum separating means 11 for extracting the liquid from the liquid reservoir 29 and separating the gypsum to return the supernatant liquid to the liquid reservoir 29.
[0008]
As apparent from FIGS. 3A and 3C, the width of the upper and lower edges (in the horizontal direction) of the exhaust gas inlet 24 is set to be sufficiently smaller than the diameter of the tower body 21, and the exhaust gas inlet duct 22 is connected to the exhaust gas. Even if it connects with the tower main body 21 via the inlet 24, it is comprised so that the intensity | strength of the tower main body 21 may not be impaired. Similarly, the widths of the upper and lower edges (in the horizontal direction) of the exhaust gas outlet 25 are also set sufficiently smaller than the diameter of the tower body 21, and the exhaust gas exhaust duct 23 is connected to the tower body via the exhaust gas outlet 25. Even if it connects to 21, it is comprised so that the intensity | strength of the tower main body 21 may not be impaired.
[0009]
Fuel is burned in the boiler to generate exhaust gas. The exhaust gas passes through a gas cooler and other exhaust gas treatment facilities, and is then introduced into the lower portion of the tower body 21 from the exhaust gas inlet 24 via the exhaust gas introduction duct 22.
[0010]
The exhaust gas introduced into the lower part of the tower main body 21 rises in the tower main body 21 and is sprayed with an alkaline absorbent slurry by the absorbent spray means 7, whereby sulfur (SO ₂ , SO _3, etc.) in the exhaust gas is removed. It is absorbed through gas-liquid contact with the absorbent slurry and desulfurized.
[0011]
The desulfurized exhaust gas is discharged from the exhaust gas discharge port 25 through the exhaust gas discharge duct 23 and is released into the atmosphere through a chimney or the like.
[0012]
On the other hand, the absorption liquid (including gypsum generated by the desulfurization reaction) collected in the liquid reservoir 29 of the absorption tower 21 is extracted by the absorbent slurry circulating means 8 and returned to the absorbent spray means 7 again. It is sprayed. Further, the liquid is appropriately extracted from the liquid reservoir 29 by the gypsum separation means 11, and the gypsum is separated and recovered, and the supernatant liquid is returned to the liquid reservoir 29, and the above process is repeated thereafter. Further, the absorbent slurry is appropriately supplied into the tower body 21 by the absorbent slurry supply means.
[0013]
[Problems to be solved by the invention]
In the case of the cylindrical (round) absorption tower as described above, the upper and lower edge portions of the exhaust gas introduction duct and the connection portion between the exhaust gas discharge duct and the tower body (that is, the exhaust gas introduction port and the exhaust gas discharge port). If the width of the column is to be widened along the peripheral wall of the tower body, the section of the tower body at that portion is not circular and the strength is reduced. Therefore, the width of the upper and lower edges of the exhaust gas inlet and the exhaust gas outlet is reduced. Cannot be taken widely (along the peripheral wall of the tower body).
[0014]
That is, in the case of a round absorption tower, the horizontal 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 absorber. Therefore, if the cross-sectional areas of the exhaust gas introduction duct and the exhaust gas exhaust duct are maintained at a certain level or more, the axial heights of the exhaust gas introduction port and the exhaust gas discharge port are inevitably increased.
[0015]
And if the height of the exhaust gas inlet and the exhaust gas outlet is large, the absorption tower becomes high accordingly, and the lift distance of the slurry circulation pump becomes long, and there is a problem that the burden on the pump is large.
[0016]
In addition, if the absorption tower is high, the structure (frame) that supports the ducts connected to the absorption tower is also high, which increases the weight and cost of the entire apparatus.
[0017]
Furthermore, in the case of a conventional round absorption tower, the gas arrival distance (distance from the gas inlet side to the opposite (tower body) side surface) is not uniform, and the gas arrival distance is long in the center, but at the end. Since it becomes shorter as it goes, there is a problem that gas drift tends to occur (see FIG. 2B).
[0018]
Moreover, since the horizontal cross section of the tower body is circular, in order to spray the absorbent slurry uniformly in the tower body, the arrangement of the above-mentioned absorbent spray means (spray nozzle) is individually set every time the tower diameter changes. There was a problem that had to be considered.
[0019]
Accordingly, an object of the present invention is to provide a spray-type square absorption tower of a flue gas desulfurization apparatus that can reduce the occurrence of gas drift by reducing the height of the tower, easily arranging the spray nozzle, and improving the conventional circular configuration. Is to provide.
[0020]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a liquid reservoir for storing an absorbent slurry at the bottom, an absorbent spray means at the top, introduces exhaust gas from an exhaust gas introduction duct, In an absorption tower that exhausts exhaust gas to an exhaust gas exhaust duct after desulfurization with an absorbent, the absorption tower body is formed into a rectangular box with a horizontal cross section, and the side width of the absorption tower body on the gas introduction side is the same width as the side width The exhaust gas inlet is located at the upper part of the liquid reservoir , and the exhaust gas inlet duct is formed with a horizontal section widened to match the width of the exhaust gas inlet, and downward toward the exhaust gas inlet. substantially tilted by connecting, to the further upper portion of the side surface of the absorption tower body opposed to the exhaust gas inlet, thereby forming an exhaust gas outlet of the same width as a side width, the exhaust gas discharge duct of the same width as the width Earnestly connected, this exhaust gas discharge duct provided eliminator, larger flow cross-section of the outlet side of the inlet side of the eliminator is formed to be inclined upwardly further towards the upper surface of the exhaust gas discharge duct downstream It was made to become .
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
[0023]
FIG. 1A, FIG. 1B, and FIG. 1C show a part of the flue gas desulfurization apparatus 20, which introduces exhaust gas from below and flows it upward, and applies an alkaline absorbent slurry (such as calcium carbonate) to the exhaust gas from above. The tower main body 1 of the absorption tower of the present invention for performing desulfurization by spraying is shown (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 apparatus 20).
[0024]
As is clear from these figures, the tower body 1 of the absorption tower of the present invention is configured in a box shape (square shape). A liquid reservoir 9 is formed at the bottom of the tower body 1 to store the absorbent slurry. An exhaust gas introduction duct 2 is connected to the lower part of the tower body 1 (but above the liquid reservoir 9) via an exhaust gas introduction port 4, while exhaust gas is discharged to the uppermost part of the tower body 1 via an exhaust gas discharge port 5. After the duct 3 is connected and the exhaust gas introduced into the lower part of the tower body 1 through the exhaust gas introduction duct 2 rises upward from below in the tower body 1, it passes through the eliminator 6 and the exhaust gas discharge duct 3. It is supposed to be discharged. The discharge duct 3 is supported by the frame 10.
[0025]
In the present embodiment, it is desirable to provide the tower body 1 with an appropriate reinforcing means (not shown) for supplementing its strength.
[0026]
Various equipments (not shown) such as a boiler, a gas cooler, and a heat recovery gas gas heater are connected to the upstream side of the exhaust gas introduction duct 2, while a reheating gas gas heater, a chimney, etc. (not shown) are connected to the downstream side of the exhaust gas exhaust duct 3. Connected.
[0027]
Further, in the tower main body 1, an absorbent spray means 7 for spraying the absorbent slurry to the exhaust gas is installed at the upper part (but below the exhaust gas outlet 5) as shown in FIG. 1B. The absorbent spray means 7 and the tower body 1 are further illustrated with an absorbent slurry circulating means 8 for pumping the absorbent slurry collected in the liquid reservoir 9 of the tower body 1 and returning it to the absorbent spray means 7 as shown in the figure. Is provided. An absorbent slurry supply means (not shown) that is connected to the tower body 1 and supplies the absorbent slurry into the tower body 1 is installed.
[0028]
Connected to the liquid reservoir 9 of the tower body 1 is a gypsum separating means 11 for extracting the liquid from the liquid reservoir 9 and separating the gypsum to return the supernatant liquid to the liquid reservoir 9.
[0029]
As is clear from FIGS. 1A and 1C, the upper edge portion and the lower edge portion of the exhaust gas inlet 4 extending in the horizontal direction are both widely configured along the flat side wall of the tower body 1. Moreover, the upper edge part and lower edge part which extend in the horizontal direction of the exhaust gas discharge port 5 are both widely configured along the flat side wall of the tower body 1.
[0030]
In the present invention, in this way, in the exhaust gas inlet 4 and the exhaust gas outlet 5, that is, in the connection portion between the exhaust gas inlet duct 2 and the exhaust gas exhaust duct 3 and the tower body 1, the upper and lower edges in the horizontal direction. Since the tower body 1 is reinforced as described above in the case of a square type, there is no risk of losing strength even if configured in this way. The height of the port 4 and the exhaust gas discharge port 5 can be lowered.
[0031]
That is, the exhaust gas inlet 4 and the exhaust gas outlet 5 can be configured in a horizontally long (flat) shape. Therefore, the height of the tower main body 1 is lower than the height of the conventional tower main body 21 by the amount of the reduced duct height. (Refer to FIG. 1B and FIG. 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 can be configured lower than the frame 31 (see FIG. 3B) in the conventional apparatus.
[0032]
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 then introduced into the lower portion of the tower body 1 from the exhaust gas inlet 4 via the exhaust gas introduction duct 2.
[0033]
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 spray means 7, whereby sulfur (SO ₂ , SO _3, etc.) in the exhaust gas is removed. It is absorbed through gas-liquid contact with the absorbent slurry and desulfurized.
[0034]
The desulfurized exhaust gas is discharged from the exhaust gas discharge port 5 through the exhaust gas discharge duct 3, and is released into the atmosphere through a chimney or the like.
[0035]
On the other hand, the absorption liquid (including gypsum generated by the above desulfurization reaction) collected in the liquid reservoir 9 of the absorption tower 1 is appropriately extracted by the absorbent slurry circulating means 8 and separated again after the gypsum is separated. It returns to the agent spray means 7 and is sprayed. The slurry liquid is appropriately extracted from the liquid reservoir 9 by the gypsum separating means 11, and the gypsum is separated and recovered, and the supernatant liquid is returned to the liquid reservoir 9, and the above process is repeated. Further, the absorbent slurry is appropriately supplied into the tower body 1 by the absorbent slurry supply means.
[0036]
In the tower main body 1 of the absorption tower of the present invention, the horizontal cross section is rectangular. Therefore, the gas arrival distance when the exhaust gas is introduced into the tower main body 1 from the exhaust gas inlet 4 (opposite from the exhaust gas inlet 4 side). Since the distance to the side surface (to the side of the tower body 1) is uniform, the gas drift is less than that of the conventional absorption tower 21 (the gas arrival distance differs between the central portion and the end portion of the absorption tower 21). (See FIGS. 2A and 2B).
[0037]
Incidentally, the gas drift in the horizontal section X (see FIG. 2A) immediately above the exhaust gas inlet 4 of the square absorption tower 1 of the present invention is about 11%, while the exhaust gas of the conventional round absorption tower 21 is about 11%. The degree of gas drift in the horizontal section Y immediately above the inlet 24 (the section corresponding to the horizontal section X in FIG. 2A, see FIG. 2B) is about 15%.
[0038]
Further, since the horizontal section of the tower body 1 of the absorption tower of the present invention is configured to be rectangular, the arrangement of the optimum absorbent spray (spray nozzle) means 7 for spraying the absorbent slurry uniformly in the tower body 1 The same (optimum) spray nozzle arrangement can always be applied even if the column diameter, that is, the column size is changed (in contrast, in the conventional round absorption tower 21, as described above, the absorbent The arrangement of the spray means 7 must be examined individually each time the tower diameter of the absorption tower 21 changes).
[0039]
In short, in the present invention, in the present invention, the connecting portion between the exhaust gas introduction duct and the exhaust duct and the rectangular tower body, that is, the duct in the vicinity of the exhaust gas introduction port and the exhaust gas discharge port can be configured flat, and thus the entire height of the absorption tower Can be significantly reduced.
[0040]
As a result, the lifting distance of the slurry circulation pump is shortened, the burden on the pump is reduced, and the structure (frame) that supports the duct connected to the absorption tower can be configured low, thereby reducing the weight and cost of the entire apparatus. .
[0041]
Further, in the present invention, the horizontal cross section of the tower body is rectangular, and therefore the gas reach distance when the exhaust gas is introduced into the tower body from the exhaust gas inlet (distance from the exhaust gas inlet side to the opposite side of the tower) As a result, the gas drift is reduced as compared with the conventional absorption tower in which the gas arrival distance is different between the central part and the end part of the tower, so that improvement of the desulfurization efficiency is expected.
[0042]
In addition, since the horizontal section of the tower body is rectangular, it is easy to determine the optimal spray nozzle arrangement for uniformly spraying the absorbent slurry, and always the same (optimum) spray nozzle even if the tower size changes. Since the arrangement can be applied, it is easier to standardize the spray nozzle arrangement than the conventional absorption tower.
[0043]
【The invention's effect】
In summary, the absorption tower of the flue gas desulfurization apparatus according to the present invention brings about the following excellent effects.
[0044]
(1) exhaust gas inlet and be flattened configuration the duct in the vicinity of the exhaust gas outlet can be significantly reduced overall height of the intake Osamuto. As a result, the structure (frame) that supports the ducts and the like connected to the absorption tower can be configured low, and the weight and cost of the entire apparatus can be reduced.
[0045]
(2) The horizontal cross section of the tower body is rectangular, so the gas reach distance (distance from the exhaust gas inlet side to the opposite side of the tower) when exhaust gas is introduced into the tower body from the exhaust gas inlet is uniform. Therefore, the gas drift is reduced and the desulfurization rate is improved as compared with the conventional absorption tower in which the gas reach distance is different between the central part and the end part of the tower.
[0046]
(3) Since the horizontal cross section of the tower body is rectangular, it is easy to determine the optimal spray nozzle arrangement for uniformly spraying the absorbent slurry and is always the same (optimal) even if the tower size changes. 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 square absorption tower (which is a part of a flue gas desulfurization apparatus) of the present invention.
1B is a vertical cross-sectional view of the absorption tower of FIG. 1A.
1C is a bird's-eye view of the absorption tower of FIG. 1A.
FIG. 2A is a diagram showing the result of gas flow simulation in the rectangular absorption tower of the present invention.
FIG. 2B is a diagram showing the results of gas flow simulation in a conventional round absorption tower.
FIG. 3A is a horizontal sectional view of a conventional round absorption tower (which is a part of a flue gas desulfurization apparatus).
3B is a vertical cross-sectional view of the absorption tower of FIG. 3A.
3C is a bird's-eye view of the absorption tower of FIG. 3A.
[Explanation of symbols]
1 Absorption tower body 4 Exhaust gas inlet 5 Exhaust gas outlet 7 Absorbent spray means 9 Liquid reservoir

Claims (1)

A liquid reservoir for storing the absorbent slurry is formed at the bottom, and an absorbent spray means is provided at the top. After exhaust gas is introduced from the exhaust gas introduction duct and desulfurized with the absorbent from the absorbent spray means, the exhaust gas is exhausted. in the absorption tower for discharging to the discharge duct, the absorption tower body is formed into a box-shaped horizontal cross-section rectangular upper part of the liquid reservoir to the exhaust gas inlet port of the same width as the side surface width to the side of the gas inlet side of the absorption tower body and forming situated in the exhaust gas introducing duct is formed by widening the horizontal section to fit the width of the exhaust gas inlet and connected by inclined downwardly toward the exhaust gas inlet, further the exhaust gas inlet the upper side surface of the absorption tower body to mouth facing, to form the exhaust gas outlet of the same width as a side width, connected substantially horizontally exhaust gas discharge duct of the same width as the width, in the exhaust gas discharge duct The Rimineta provided, the exhaust gas which is characterized in that as the flow path cross-section of the outlet side increases further for the formation to the inlet side of the eliminator to be inclined upwardly an upper surface of the exhaust gas discharge duct toward the downstream side Spray type square absorption tower of flue gas desulfurization equipment that introduces and desulfurizes.

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