JPH09299745A - Wet process flue gas desurfurizing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbing soln. spray type wet process flue gas desurfurizing device capable of preventing the blowoff of gas and improving a desulfurizing efficiency. SOLUTION: A spray nozzle 4 is arranged near the wall surface of a waste gas passage, and is composed of the spray nozzles 23 different in their spray momentum (different in pressure, spray angle, flow rate, etc.). In this way, a local blowoff of the gas is prevented by varying the part where gas is apt to flow by changing the spray momentum in the direction orthogonal to a gas flow as for every spray step. Also the variation of the spray momentum in the surface orthogonal to the gas flow is reduced and the local blowoff of the gas is prevented by disposing at least one spray stage in which the dotty spray nozzles disposed in a tower are arranged in the surface orthogonal to the gas flow in addition of the spray nozzle disposed at the wall.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet flue gas desulfurization apparatus equipped with an absorption tower for removing sulfur oxides (SOx) in boiler exhaust gas, and particularly, in the vicinity of a wall surface forming an exhaust gas passage of the absorption tower. A wet flue gas desulfurization device in which a spray nozzle is arranged in the absorption tower to spray the absorbing liquid from the vicinity of the tower wall, the local blowing of gas is prevented by optimizing the spraying method, and the desulfurization performance is improved. Is.

[0002]

2. Description of the Related Art Sulfur oxides in flue gas generated by combustion of fossil twisting materials in thermal power plants and the like, especially SO.
₂ is one of the main causes of environmental problems such as air pollution and acid rain, and the spread of flue gas desulfurization equipment on a global scale has recently been desired.

The main current desulfurization system is a wet method based on the limestone-one-gypsum method, and the spray method, which has the most achievement and has the highest reliability, is widely adopted all over the world. This spray type desulfurization device has high desulfurization performance, and the basic technology is almost established.

An example of a conventional side spray type wet flue gas desulfurization apparatus is shown in FIGS. 20 and 21. 20 is a vertical sectional view in the gas flow direction, and FIG. 21 is C-C ′ in FIG.
It is a sectional arrow view. This wet flue gas desulfurization apparatus mainly comprises an absorption tower main body 1, an inlet duct 2, an outlet duct 3, a spray nozzle 4, an absorbing liquid circulation pump 5, a circulation tank 6, an agitator 7, an air blowing pipe 8, a mist eliminator 9, and an absorption. It is composed of a liquid extraction pipe 10, a spray header 11, an exhaust gas flow path 12, and the like. A plurality of spray nozzles 4 are installed in a direction orthogonal to the gas flow in the exhaust gas passage 12, and a plurality of stages are installed in the gas flow direction. Also, the agitator 7 and the air blowing pipe 8
Is installed in the circulation tank 6 in the lower part of the absorption tower where the absorbing liquid stays, and the mist eliminator 9 is installed in the outlet duct 3.

Exhaust gas discharged from a boiler (not shown) is introduced into the absorber main body 1 from the inlet duct 2 by a desulfurization fan (not shown), and is discharged from the outlet duct 3 through the exhaust gas passage 12. In the meantime, in the exhaust gas passage 12 of the absorption tower main body 1, the absorption liquid containing calcium carbonate in the circulation tank 6 is sprayed from the plurality of spray nozzles 4 by the absorption liquid circulation pump 5, and the absorption liquid and the exhaust gas come into gas-liquid contact. Be seen. At this time, the absorbing liquid selectively absorbs SO ₂ in the exhaust gas and forms calcium sulfite. The absorption liquid that has generated calcium sulfite once stays in the absorption liquid circulation tank 6, and while being stirred by the oxidizing stirrer 7, the oxygen in the air supplied from the air blowing pipe 8 oxidizes the calcium sulfite in the absorption liquid to form sulfuric acid. Produces calcium (gypsum).

A part of the absorption liquid in the absorption liquid circulation tank 6 in which calcium carbonate and gypsum coexist is oxidized by the absorption liquid circulation pump 5 to produce calcium sulfate (gypsum). Part of the absorption liquid in the absorption liquid circulation tank 6 in which calcium carbonate and gypsum coexist is sent again to the spray nozzle 4 by the absorption liquid circulation pump 5, and part of the absorption liquid is discharged from the absorption liquid extraction pipe 10 to treat waste liquid (not shown). It is sent to the gypsum recovery system. Further, among the absorption liquids sprayed from the spray nozzle 4 and atomized, those having a small droplet size are entrained in the exhaust gas, but are collected by the mist eliminator 9 provided in the outlet duct 3.

Since the wet flue gas desulfurization apparatus having the above-mentioned structure is expensive, its penetration rate in developing countries is still low.
Therefore, in order to increase the penetration rate of desulfurization equipment worldwide, it is important to significantly reduce the equipment cost and operating cost of the desulfurization equipment.

A concrete means for reducing the equipment cost of the desulfurization apparatus is to make the absorption tower compact. However, if the gas flow velocity in the absorption tower is increased in order to make the absorption tower compact, the tower cross-sectional area becomes small and the spray nozzle 4 And it becomes difficult to install the spray header 11 in the absorption tower. As a countermeasure, the spray header 11 is installed outside the tower, and the spray nozzle 4 is attached near the tower wall, so that the insert in the tower can be eliminated.

However, if the spray nozzle 4 is arranged only on one surface of the absorption tower main body 1, the gas is largely diverted to the side where the spray nozzle 4 is not installed, so that the desulfurization performance is deteriorated. Therefore, as shown in FIG. 20, the spray nozzles 4 are installed on the inlet duct wall surfaces of the facing side wall surfaces facing each other, and the absorbing liquid is sprayed from the both side wall surfaces toward the center of the tower, so that the gas drift can be prevented to some extent. it can. However, as compared with the vicinity of the spray nozzle 4, at the center of the exhaust gas passage 12, that is, at the position X where the sprayed absorption liquid shown in FIG. 20 and FIG. The gas blows through the position X where the liquid intersects, and high desulfurization performance cannot be obtained.

From the above, in order to make the absorption tower compact and to reduce the cost, it is necessary to prevent gas blow-through and prevent the desulfurization performance from decreasing.
It is important to install the spray nozzle 4 near the tower wall of the absorption tower so as to spray the absorbing liquid from the tower wall.

[0011]

In the above-mentioned prior art, in a side spray type wet flue gas desulfurization apparatus in which a spray nozzle is arranged in the vicinity of the tower wall, local blow-through of gas is prevented,
No consideration has been given to preventing deterioration of desulfurization performance,
There has been a problem that equipment costs and operating costs are high in order to obtain high desulfurization performance.

An object of the present invention is to obtain an absorbing liquid spray type wet flue gas desulfurization apparatus capable of preventing gas blow-through and improving desulfurization performance.

[0013]

The above object of the present invention can be achieved by the following constitution. That is, while arranging the spray nozzle in the vicinity of the wall surface of the exhaust gas passage, at least one spray stage is installed in the gas flow direction of the exhaust gas passage,
In a wet flue gas desulfurization device that removes sulfur oxides in the exhaust gas by contacting the absorbing liquid injected from the spray nozzle with the exhaust gas, the spray nozzle disposed near the wall of the exhaust gas passage is a plurality of types of spray nozzles having different spray momentums. It is a wet flue gas desulfurization device configured by.

The following structures can be adopted as the spray nozzles having different spray momentums. It consists of spray nozzles with different spray pressures. The spray nozzles have spray angles different from each other. It consists of spray nozzles with different spray flow rates. The spray nozzles having the same spray flow rate are configured so that the number of spray stages is different from each other on opposing wall surfaces.

The spray nozzles are arranged in the vicinity of opposite side walls of the exhaust gas flow passage, respectively, and are arranged so that the spray momentums of the spray nozzles of the adjacent spray stages are different for each spray stage on the same side wall surface. The spray nozzles are arranged near the opposing walls of the exhaust gas channel, and the spray momentums of the opposing spray nozzles are different from each other for each spray stage. The spray nozzles having different spray momentums are configured such that the number of spray stages having spray nozzles having the same spray flow rate is different from each other on both opposing wall surfaces. The spray momentum of the spray nozzle of each spray stage on one side wall is different from the spray momentum of the spray nozzle of each spray stage arranged on the other side wall surface among the spray nozzles arranged near both opposing walls of the exhaust gas flow path. It is constituted by a spray nozzle.

In the above wet flue gas desulfurization apparatus of the present invention,
A configuration may be employed in which the position at which the absorbents injected from the spray nozzles arranged near the opposing side wall surfaces of the exhaust gas flow path intersect is changed for each spray stage.

According to the present invention, when the absorbing liquid is sprayed into the exhaust gas passage having a uniform gas flow at an arbitrary angle with respect to the gas flow direction, the gas flow changes in accordance with the degree of the spray. This is because the spray momentum of the absorbing liquid is transmitted to the gas, and the larger the spray momentum, the stronger the influence on the gas flow. In addition, as the spray momentum of the absorbing liquid in the direction perpendicular to the gas flow increases, the resistance of the absorbing liquid to the gas increases, which causes a change in the gas flow direction.

In the case of an absorption tower in a side spray type wet flue gas desulfurization apparatus, since the absorbing liquid immediately after being ejected from the spray nozzle near the wall has a large spray momentum and a large resistance to gas, the gas hardly flows in the vicinity of the nozzle. Therefore, when the absorbing liquid is sprayed from both wall surfaces facing each other, the gas flows intensively almost at the center of the exhaust gas passage where the spray momentum of the absorbing liquid in the direction orthogonal to the gas flow is the smallest. When the spray momentum in the direction orthogonal to the gas flow of the absorbing liquid ejected from the spray nozzle is almost uniform as in the prior art, all the parts where the gas easily flows are almost the center of the exhaust gas flow path, and this part is the gas. Blows through,
High desulfurization performance cannot be obtained.

On the other hand, according to the present invention, by changing the spray momentum in the direction orthogonal to the gas flow of the absorbing liquid ejected from the spray nozzle for each spray nozzle or each spray stage, the portion where the gas easily flows is changed. Can be made. As a result, local blow-through of gas is prevented, and high desulfurization performance can be obtained.

The above object of the present invention can be achieved by the following constitution. That is, the spray nozzle is arranged near the wall surface of the exhaust gas passage, and at least one spray stage is installed in the gas flow direction of the exhaust gas passage, and the absorption liquid injected from the spray nozzle is brought into contact with the exhaust gas to effect sulfur oxidation in the exhaust gas. In a wet flue gas desulfurization device for removing substances, in addition to the wall-mounted spray nozzle arranged near the wall surface, at least one spray stage in which tower-installed spray nozzles are scattered on a plane orthogonal to the gas flow is installed. It is a smoke desulfurizer.

At this time, the spray nozzle installed in the tower can be arranged in the exhaust gas passage as follows. An in-column installed spray nozzle is installed at the most downstream spray stage of the exhaust gas flow path. In-column installed spray nozzles are installed at the uppermost and lowermost spray stages of the exhaust gas flow path. The spray stages in which the tower-installed spray nozzles are arranged are alternately arranged in the gas flow direction of the exhaust stages and the spray stages in which the spray nozzles are disposed near the wall surface of the exhaust gas passage. The spray direction of the absorbing liquid of the spray nozzle installed in the tower is arranged so as to face the countercurrent or cocurrent direction or the combined direction of countercurrent and cocurrent with the flow direction of the exhaust gas.

According to the above-mentioned present invention, even when the spray nozzles installed in the tower are scattered on the plane orthogonal to the gas flow, the change of the spray momentum in the plane orthogonal to the gas flow is small, so that the above-mentioned local portion is formed. Gas is prevented from passing through, and high desulfurization performance can be obtained. The wet flue gas desulfurization apparatus of the present invention is a vertical type equipped with an exhaust gas flow path in which gas flows vertically or a side spray type equipped with an exhaust gas flow path in which gas flows in a non-vertical direction including the horizontal direction. Including.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view in the gas flow direction of a side spray type wet flue gas desulfurization apparatus according to an embodiment of the present invention,
2 is a sectional view taken along the line A-A 'in FIG. 1, FIG. 3 is a distribution diagram of gas flow velocity and spray momentum in the spray portion of the exhaust gas passage, and FIG. 4 is a comparison of desulfurization performance between the conventional technique and this embodiment. 5 shows another embodiment of the present invention. FIG. 5 is a longitudinal sectional view of a side spray type wet flue gas desulfurization apparatus in which the arrangement of the high pressure spray nozzle is changed, and FIG. 6 also shows another embodiment of the present invention. Fig. 7 is a vertical sectional view of a side spray type wet flue gas desulfurization apparatus combined with a spray nozzle having a large jetting angle of the absorbing liquid, and Fig. 7 also shows another embodiment of the present invention, in which a large capacity spray nozzle is combined. 8 and 9 show another embodiment of the present invention. FIG. 8 is a side spray type wet flue gas desulfurization apparatus in which the number of spray nozzles is changed. FIG. 9 is a vertical sectional view of FIG.
FIG. 10 shows another embodiment of the present invention in which the cross section of the exhaust gas flow path is a round shape, taken along the line B-B 'in the drawing.

In FIGS. 1 to 10, the numbers 1 to 12 of the respective members / devices are the same as those shown in the prior art of FIGS. 20 and 21 and have the same functions, and the description thereof will be omitted. However, the circulation tank 6 is included in the embodiment of the present invention.
The inlet duct 2 is provided with a high-pressure circulation pump 21, a high-pressure spray header 22, a high-pressure spray nozzle 23, etc. for spraying the absorbed liquid at a pressure higher than the pressure of the spray nozzle 4, and the inlet duct 2 has a gas flow direction of the spray nozzle 4. Large spray angle spray nozzle 24 and spray nozzle 4 for spraying the absorbing liquid at a spray angle larger than the spray angle with respect to
A large-capacity spray nozzle 25 for ejecting a larger amount of the absorbing liquid than that is provided.

Before describing the embodiment, the difference in the arrangement of the spray nozzles will be described in comparison with the conventional desulfurization apparatus. That is, in the conventional desulfurization apparatus, the spray nozzles 4 having substantially the same spray pressure, injection angle, and spray flow rate are arranged in the exhaust gas passage 12 at the opposing wall surface positions. In the spray nozzle, the spray nozzles 4 and the high-pressure spray nozzles 23 or the spray nozzles 4 and the spray nozzles 24 and 25 having different spray angles and spray flow rates, that is, different spray momentums are arranged at the opposite positions of the exhaust gas passage 12.

In the embodiment shown in FIG. 1, a spray nozzle 4 and a high pressure spray nozzle 23, an absorbing liquid circulation pump 5 and a high pressure circulation pump 21, a spray header 11 and a high pressure spray header 22 are provided respectively. A high pressure spray nozzle 23 is attached to the high pressure spray header 22.

A spray header 11 and a high pressure spray header 22 are provided on the ceiling and the bottom, respectively, in substantially the same plane orthogonal to the gas flow, and the spray header 11 and the high pressure spray header 22 are alternately replaced in the gas flow direction. It is arranged. That is, the spray nozzle 4 is arranged on the ceiling wall surface side of the first stage on the most upstream side, the high pressure spray nozzle 23 is arranged on the bottom side wall surface, and the high pressure spray nozzle 23 is arranged on the ceiling side wall surface and the spray nozzle on the bottom side wall surface in the second stage. 4 are arranged.

FIG. 3 shows the distribution of the spray momentum of the absorbing liquid and the flow velocity distribution of the gas flow in the spray portion of the exhaust gas passage 12. FIG. 3 (a) shows the case where the conventional spray nozzle 4 is used alone. 3B is a high pressure spray nozzle 23.
3 (c) is used alone, FIG. 3 (c) shows the case where the spray nozzle 4 and the high pressure spray nozzle 23 are combined, FIG.
The case where the position X where the absorbing liquid intersects is changed in the vertical direction for each spray stage.

First, as shown in FIG. 3A, the spray nozzle 4
When used alone, the spray momentum in the direction orthogonal to the gas flow of the absorbing liquid is the highest in the vicinity of the spray nozzle 4, and the spray momentum decreases as the distance from the spray nozzle 4 increases. Since the resistance of the absorbing liquid to the gas is small in the region where the spray momentum is small, the exhaust gas easily flows through this region.

On the other hand, when the high pressure spray nozzle 23 is used alone as shown in FIG. 3B, the spray momentum at the initial stage of the absorbing liquid spray is larger than that in the case of FIG. 3A, but the spray moment increases as the distance from the high pressure spray nozzle 23 increases. The momentum is still reduced, and the exhaust gas easily flows through the portion where the spray momentum is small as in the case of FIG. 3A. Actually, as shown in FIG. 3C, the spray nozzle 4 and the high-pressure spray nozzle 23 are used in combination, but in this case, the spray momentum is a superposition of FIG. 3A and FIG. The spray momentum at the intersecting position X becomes the smallest, and the exhaust gas flows intensively through this portion.

However, in this embodiment, by alternately arranging the spray nozzles 4 and the high-pressure spray nozzles 23 as shown in FIG. 3 (d), the position X where the absorbing liquid intersects, that is, the position where the gas is easily blown out, becomes the spray stage. It changes vertically each time. Therefore, the blow-through of gas in the central portion of the exhaust gas passage 12 as in the prior art is prevented, the flow velocity distribution of the exhaust gas becomes almost uniform, and the deterioration of desulfurization performance can be prevented. As a result, high desulfurization performance can be obtained without increasing the number of spray nozzles 4 or increasing the absorption liquid circulation amount.

Further, in the case of this embodiment, even if the boiler load changes and the amount of exhaust gas introduced into the absorption tower body 1 changes,
By controlling the pressure balance, it is possible to deal with changes in the gas blow-through degree.

Further, in this embodiment, the high pressure spray nozzle 23
However, the conventional spray nozzle 4 may be used instead of the high pressure spray nozzle 23 to increase the spray pressure.

FIG. 4 compares the present embodiment with the prior art regarding the desulfurization performance. In the case of the present embodiment, in addition to the conventional spray nozzle 4, a high-pressure spray nozzle 23 is newly provided, and the position where the absorbing liquid intersects, that is, the position where the gas is easily blown out is changed vertically for each spray stage. 23 are arranged. Therefore, the blow-through of gas in the central portion of the exhaust gas passage 12 as in the conventional technique is suppressed, and the desulfurization performance is higher than that in the conventional technique. When the desulfurization performance of the conventional technique is 1, it is about 1.3 times in this embodiment.

FIG. 5 shows another embodiment of the embodiment of the present invention shown in FIG. 1, in which the spray nozzles 4 and the high pressure spray nozzles 23 are alternately arranged, whereas the embodiment of FIG. In the embodiment shown in FIG. 5, the spray nozzle 4 is disposed on the ceiling side of the first and second stages of the spray stage, the high pressure spray nozzle 23 is disposed on the ceiling side of the third and fourth stages, and the ceiling side is defined on the bottom side. Conversely, the first stage, the second stage, the high-pressure spray nozzle 23, the third stage, the fourth stage
The spray nozzle 4 is arranged at the stage.

As described above, in the embodiment shown in FIG. 1, the spray nozzles 4 and the high pressure spray nozzles 23 are alternately arranged, whereas in the embodiment shown in FIG. Since they are arranged alternately, the other points are the same as those in the embodiment of FIG.

In the embodiment shown in FIG. 5, since the spray nozzle 4 and the high-pressure spray nozzle 23 are arranged every two, the position X where the absorbing liquid intersects, that is, the position where the gas is easily blown out, is continuous in two stages. For this reason, although gas blow-through is more likely to occur as compared with the embodiment of FIG. 1, the resistance of the absorbing liquid to gas is small, and therefore the pressure loss in the exhaust gas flow path is low. Therefore, the power of the desulfurization fan can be reduced. In the embodiment shown in FIG. 5, the spray nozzle 4 and the high-pressure spray nozzle 23 are arranged every two, but they may be arranged every three.

FIG. 6 shows another embodiment of the present invention.
The difference is that the high-pressure circulation pump 21 and the high-pressure spray header 22 in the embodiment of FIG. 1 are not installed, and a large injection angle spray nozzle 24 is arranged instead of the high-pressure spray nozzle 23 in the embodiment of FIG. Since the other points are the same as those of the embodiment shown in FIG. 1, description thereof will be omitted.

In the embodiment of FIG. 6, the spray momentum in the direction orthogonal to the gas flow is changed by changing the injection angle of the absorbing liquid with respect to the gas flow direction. Since the absorbing liquid ejected from the large-injection-angle spray nozzle 24 has a large velocity component in the direction orthogonal to the gas flow, the spray momentum is larger than that of the absorbing liquid ejected from the spray nozzle 4. Therefore, the position X where the absorbing liquid intersects, that is, the position where the gas is easily blown through, changes in the vertical direction for each spray stage.

Further, although the large jet angle spray nozzle 24 is used in this embodiment, the conventional spray nozzle 4 is used in place of the large jet angle spray nozzle 24, and the spray header 11 is used.
By increasing the attachment angle of the spray nozzle 4 to
The jet angle of the absorbing liquid with respect to the gas flow direction may be increased.

In the embodiment shown in FIG. 7, a large capacity spray nozzle 25 is arranged in place of the large spray angle spray nozzle 24 in the embodiment of FIG. Other points are shown in FIG.
The description is omitted because it is the same as the embodiment described above. In the embodiment of FIG. 7, the spray momentum in the direction orthogonal to the gas flow is changed by changing the spray flow rate. Since the absorbing liquid ejected from the large-capacity spray nozzle 25 has a large mass, the amount of spray momentum in the direction orthogonal to the gas flow is larger than that of the absorbing liquid ejected from the spray nozzle 4. Therefore, the position X where the absorbing liquid intersects, that is, the position where the gas is easily blown through, changes in the vertical direction for each spray stage.

Although the large capacity spray nozzle 25 is used in the embodiment shown in FIG. 7, the conventional spray nozzle 4 may be used instead of the large capacity spray nozzle 25 to increase the spray flow rate.

The embodiment shown in FIGS. 8 and 9 is (a vertical sectional view in the gas flow direction, FIG. 9 is a sectional view taken along the line B-B 'in FIG. 8) and is a schematic view of the embodiment shown in FIG. The feature is that the number of the spray nozzles 4 on one side wall surface of the inlet duct 2 is increased instead of the capacity spray nozzle 25, and other points are the same as the embodiment shown in FIG.

In the embodiment shown in FIGS. 8 and 9, the number of spray nozzles 4 is increased and the spray flow rate is changed to change the spray momentum in the direction orthogonal to the gas flow.
Since the absorbing liquid ejected from the wall surface side having a large number of spray nozzles 4 has a large mass, the amount of spray momentum in the direction orthogonal to the gas flow is larger than that of the absorbing liquid ejected from the wall surface side having a small number of spray nozzles 4. . Therefore, the crossing point X of the absorbing liquid, that is, the position where the gas is easily blown through, changes in the vertical direction for each spray stage.

FIG. 10 shows another embodiment, which is different from the embodiment shown in FIG. 5 and the like in that the shape of the cross section orthogonal to the gas flow in the exhaust gas passage is round. Since the other points are the same as those of the above-mentioned embodiment, the description thereof will be omitted.

When the exhaust gas passage is round, the spray nozzle 4
It is not possible to clearly define the opposite wall surfaces on which the mounting is to be made.
Therefore, the opposite wall surfaces on which the spray nozzle 4 is mounted need not be completely parallel. In this embodiment, the spray nozzle 4 and the high pressure spray nozzle 23 are combined in the same manner as in the embodiment of FIG. 1 or FIG. 5, but the spray nozzle 4 and the large spray angle spray nozzle 24 as in the embodiment of FIG. As in the example, a combination of the spray nozzle 4 and the large-capacity spray nozzle 25 may be used, or a combination in which the number of the spray nozzles 4 is changed as shown in FIG.

Although the gas flows in the horizontal direction in the embodiments shown in FIGS. 1 to 10, the present invention can be applied even if the gas flow direction in the exhaust gas passage is the vertical direction or the oblique direction. Is possible. Further, in the above-described embodiment, the spraying direction of the liquid from the spray nozzle 4 is set to be the same direction as the co-current flow, that is, the gas flow. Is what you get. Further, in the above embodiment, the number of spray stages is four, but it may be two, three or five or more.

Next, a description will be given of an embodiment in which a tower-installed spray header is installed in addition to the tower-installed spray nozzle. Gas flow path 12 of the inlet duct 2 shown in FIGS.
Before describing an embodiment in which the in-tower-installed spray nozzle 26 and the in-tower-installed spray header 27 are arranged therein, the features of the arrangement of the spray nozzles will be described first.

In the prior art desulfurization apparatus, wall-mounted spray nozzles 4 are arranged on opposite wall surfaces of the exhaust gas passage 12, for example, a ceiling portion and a bottom portion, and the spray nozzle 4 is arranged at the central portion of the exhaust gas passage 12. Was not done. On the other hand, in the embodiment shown in FIGS. 11 to 19 of the present invention, a spray stage in which tower-installed spray nozzles 26 are scattered is provided on a plane orthogonal to the gas flow, and the conventional wall-mounted spray nozzle 4 is provided.
It is arranged upstream or downstream of the.

FIG. 11 (longitudinal sectional view in the gas flow direction) and FIG.
In the embodiment shown in FIG. 2 (a sectional view taken along the line A-A 'in FIG. 11), the wall-mounted spray nozzle 4 and the tower-mounted spray nozzle 26, the spray header 11 and the tower-mounted spray header 27 are respectively provided. And spray header 1
1, a wall-mounted spray nozzle 4 is attached, and a tower-mounted spray header 27 divided from the spray header 11 is mounted with a tower-mounted spray nozzle 26.

The details of the inside of the exhaust gas flow passage 12 are shown in FIG. 12, but after the wall-mounted spray nozzles 4 are connected in five stages from the upstream side, the inside of the tower in which the in-column installed spray nozzles 26 are attached to the most downstream stage A stationary spray header 27 is arranged.

FIG. 13 is a sectional view taken along the line AA 'in FIG. 12, in which the tower-installed spray nozzles 26 are arranged so as to be evenly scattered in the exhaust gas passage 12.

FIG. 14 shows the distribution of the spray momentum of the absorbing liquid and the flow velocity distribution of the gas flow in the spray portion in the exhaust gas flow path 12. FIG. 14 (a) shows the conventional wall-mounted spray nozzle 4 up and down. 14 (b) shows a case where the in-column installed spray nozzle 26 is used alone.
(C) is a case where the wall-mounted spray nozzle 4 and the tower-mounted spray nozzle 26 are combined.

First, when the wall-mounted spray nozzles 4 are arranged vertically as shown in FIG. 14A, the spray momentum in the direction orthogonal to the gas flow of the absorbing liquid is highest in the vicinity of the wall-mounted spray nozzle 4. , The spray momentum decreases as the distance from the wall-mounted spray nozzle 4 increases. Therefore,
In the case of FIG. 14A, the spray momentum at the intersection point X of the respective absorbing liquids jetted from above and below becomes the smallest. In the region where the spray momentum is small, the resistance of the absorbing liquid to the gas is small, so the exhaust gas flows intensively in this region.

On the other hand, in the case where the tower-installed spray nozzles 26 are used as shown in FIG. 14 (b), since the tower-installed spray nozzles 26 are close to each other, there is little change in the spray momentum and a uniform gas flow is obtained. can get.

If the in-column installed spray nozzle 26 is arranged on the downstream side of the wall-mounted spray nozzle 4 as shown in FIG. 14C, the uniform flow as in FIG. 14B cannot be obtained. Local blow-through of gas as shown in FIG. 14 (a) can be prevented, and a decrease in desulfurization performance can be prevented. Therefore, it is possible to obtain high desulfurization performance without increasing the number of wall-mounted spray nozzles 4 or increasing the amount of absorption liquid circulation, and it is possible to reduce equipment costs and circulation pump power.

FIG. 15 compares the embodiment shown in FIGS. 11 to 14 with respect to the desulfurization performance. In the case of the above-described embodiment of the present invention, in addition to the wall-mounted spray nozzle 4 of the prior art, an in-column installed spray nozzle 26 in which the change of the spray momentum in the plane orthogonal to the gas flow is small is newly provided, and the exhaust gas passage 12 They are evenly scattered inside.
Therefore, the blow-through of gas in the central portion of the exhaust gas passage 12 as in the conventional technique is suppressed, and the desulfurization performance is higher than that in the conventional technique. When the desulfurization performance of the prior art is 1, it is about 1.3 times in this embodiment.

FIG. 16 shows a modified example of the actual sulfur example shown in FIG. 12. In the embodiment of FIG. 12, a tower-installed spray nozzle 26 and a tower-installed spray header 27 are installed at the most downstream stage of the spray section. On the other hand, in the embodiment of FIG. 16, in addition to the most downstream stage, the in-tower installed spray nozzle 26 and the in-tower installed spray header 27 are arranged at the most upstream stage.

As described above, in the embodiment of FIG.
In the embodiment shown in FIG. 16, only the most downstream stage of the spray stages is the spray nozzle 26 installed in the column, whereas in the embodiment of FIG. Since the internally installed spray nozzle 26 is arranged and the other points are the same as those of the embodiment shown in FIGS. 11 and 12, description thereof will be omitted. Although a total of 6 spray stages are shown here, the present invention is not limited to this number of spray stages.

In the case of the embodiment shown in FIG. 12 described above, when the exhaust gas is already introduced into the absorption tower body 1 and there is already a drift in the gas flow, the gas blow-through in the wall-mounted spray nozzle 4 is promoted. Will be done. However, in the embodiment of FIG. 16, since the tower-installed spray nozzle 26 is arranged not only in the most downstream stage but also in the most upstream stage, the absorption tower body 1
The drift of gas at the inlet can be reduced. It is possible to minimize the performance deterioration in the wall-mounted spray nozzle 4.

In the embodiment shown in FIG. 17, an in-column installed spray nozzle 26 is arranged instead of the wall-mounted spray nozzles 4 in the second and fourth stages from the upstream side in the embodiment of FIG. Since the other points are the same as those of the embodiment shown in FIGS. 11 and 12, the description thereof will be omitted.

In the embodiment shown in FIG. 17, the wall-mounted spray nozzles 4 and the tower-mounted spray nozzles 26 are alternately arranged. In this case, since the gas that is about to blow through at the wall-mounted spray nozzle 4 can be reliably rectified by the tower-mounted spray nozzle 26 that is arranged in each stage, it is possible to suppress the deterioration of the desulfurization performance due to the gas blow-through. The largest.

In the embodiment shown in FIG. 18, the direction of the spray nozzle 26 installed in the tower at the most downstream stage in the embodiment of FIG.
It is arranged in the same parallel flow as the gas flow. Since the other points are the same as those of the embodiment shown in FIGS. 11 and 12, the description thereof will be omitted.

When the in-column installed spray nozzle 26 is arranged in a co-current direction as in the embodiment shown in FIG. 18, the spray momentum is reduced and the resistance to gas is reduced, so that the effect of preventing gas blow-through is small. However, since the pressure loss of gas is low, the fan power can be reduced.

Note that, as in the embodiment shown in FIG.
In addition, the directions of the spray nozzles 26 installed in the tower in the embodiment shown in FIG.

The embodiment shown in FIG. 19 is one in which the tower-mounted spray nozzles 26 in the uppermost stream in the embodiment shown in FIG. is there. Figure 1 for other points
Since it is the same as the embodiment shown in FIG.

In the embodiment shown in FIG. 19, a countercurrent tower-mounted spray nozzle 26 and a cocurrent tower-mounted spray nozzle 26 are provided.
And are combined. In this case, compared with the embodiment of FIG. 16, although the gas rectification effect in the co-current tower-installed spray nozzle 26 partly decreases, the gas pressure loss can be decreased and the fan power can be decreased. You can

It should be noted that, as in the embodiment shown in FIG.
Also, the directions of the spray nozzle 26 installed in the tower in the embodiment shown in FIG. 17 may be combined with co-current and counter-current.

Although the gas flows in the horizontal direction in the embodiments shown in FIGS. 11 to 19, the present invention is applicable even if the gas flow direction in the exhaust gas passage is the vertical direction or the oblique direction. Is possible. Although the number of spray stages is 4 or 6 in the above embodiment, the number of spray stages of the present invention may be 6 or less or 6 or more.

[0070]

As described above, according to the present invention, spray nozzles having different spray momentums of the absorbing liquid in the direction orthogonal to the gas flow in the exhaust gas passage are combined, and the position where the gas is easily blown out is set for each spray stage. By changing it, local blow-through of gas can be prevented, and high desulfurization performance can be obtained.

Further, according to the present invention, by combining the conventional wall-mounted spray nozzle with the tower-mounted spray nozzle, it is possible to prevent local gas blow-through and obtain high desulfurization performance.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view in the gas flow direction of a side spray type wet flue gas desulfurization apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line A-A ′ in FIG.

FIG. 3 is a distribution diagram of gas flow velocity and spray momentum in a spray portion of an exhaust gas passage.

FIG. 4 is a comparative diagram comparing the desulfurization performances of the conventional technology and this embodiment.

FIG. 5 shows an embodiment of the present invention and is a vertical cross-sectional view of a side spray type wet flue gas desulfurization apparatus in which the arrangement of the high pressure spray nozzle is changed.

FIG. 6 shows an embodiment of the present invention and is a vertical cross-sectional view of a side spray type wet flue gas desulfurization apparatus combined with a spray nozzle having a large jet angle of an absorbing liquid.

FIG. 7 shows an embodiment of the present invention and is a vertical cross-sectional view of a side spray type wet flue gas desulfurization apparatus combined with a large capacity spray nozzle.

FIG. 8 is a vertical cross-sectional view of a side spray type wet flue gas desulfurization apparatus in which the number of spray nozzles is changed according to an embodiment of the present invention.

FIG. 9 shows an embodiment of the present invention, and FIG.
FIG. 6 is a sectional view taken along line B-B ′ of FIG.

FIG. 10 shows an embodiment of the present invention and is a cross-sectional view of a round exhaust gas passage.

FIG. 11 shows an embodiment of the present invention and is a vertical cross-sectional view of a side spray type wet flue gas desulfurization apparatus in a gas flow direction.

12 is a detailed view of a spray portion of the exhaust gas passage in FIG.

FIG. 13 is a cross-sectional view taken along the line AA ′ in FIG.

FIG. 14 is a distribution diagram of gas flow velocity and spray momentum in the spray portion of the exhaust gas passage in FIG.

FIG. 15 is a comparative diagram comparing the desulfurization performances of the conventional technology and this embodiment.

FIG. 16 shows an embodiment of the present invention, and is a detailed view of a spray section in a side spray type wet flue gas desulfurization apparatus in which tower-installed spray nozzles are arranged on the most upstream side and the most downstream side of the spray section. .

FIG. 17 is a detailed view of a spray portion in a side spray type wet flue gas desulfurization apparatus in which an in-column installed spray nozzle is arranged on the downstream side of all the wall installed spray nozzles, showing an embodiment of the present invention. .

FIG. 18 shows an embodiment of the present invention, and is a detailed view of a spray section in a side spray type wet flue gas desulfurization apparatus in which a tower installed type spray nozzle arranged on the most downstream side of the spray section is in parallel flow. is there.

FIG. 19 shows an embodiment of the present invention and is a detailed view of a spray section in a side spray type wet flue gas desulfurization apparatus in which a tower-installed spray nozzle on the most upstream side is in parallel flow.

FIG. 20 is a longitudinal sectional view of a conventional wet flue gas desulfurization apparatus showing a conventional technology.

FIG. 21 shows a conventional technique, and is a C in FIG.
It is a 1'C 'cross section arrow line view.

[Explanation of symbols]

1 absorption tower main body 2 inlet duct 3 outlet duct 4 spray nozzle 5 absorption liquid circulation pump 6 circulation tank 7 stirrer 8 air blowing pipe 9 mist eliminator 10 absorption liquid extraction pipe 11 spray header 12 exhaust gas flow passage 21 high pressure circulation pump 22 high pressure spray header 23 High Pressure Spray Nozzle 24 Large Spray Angle Spray Nozzle 25 Large Capacity Spray Nozzle 26 Tower-mounted Spray Nozzle 27 Tower-mounted Spray Header

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirofumi Yoshikawa 3-36 Takaracho, Kure-shi, Hiroshima Babcock Hitachi Ltd. Kure Laboratory (72) Noriaki Taniguchi 6-9 Takaracho, Kure-shi, Hiroshima Babcock Hitachi Ltd. Kure Factory

Claims (15)

[Claims] 1. A spray nozzle is disposed in the vicinity of the wall surface of the exhaust gas flow path, and at least one spray stage is installed in the gas flow direction of the exhaust gas flow path to bring the absorbing liquid injected from the spray nozzle into contact with the exhaust gas, and In the wet flue gas desulfurization apparatus for removing sulfur oxides, the spray nozzle arranged near the wall of the exhaust gas flow path is composed of a plurality of types of spray nozzles having different spray momentums. 2. The wet flue gas desulfurization apparatus according to claim 1, wherein the spray nozzles having different spray momentums are composed of spray nozzles having different spray pressures. 3. The wet flue gas desulfurization apparatus according to claim 1, wherein the spray nozzles having different spray momentums are composed of spray nozzles having different spray injection angles. 4. The wet flue gas desulfurization apparatus according to claim 1, wherein the spray nozzles having different spray momentums are composed of spray nozzles having different spray flow rates. 5. The spray nozzles are arranged near the opposite side walls of the exhaust gas passage, respectively, and the spray momentums of the spray nozzles facing each other in each spray stage are different from each other. The wet flue gas desulfurization apparatus according to any one of 1 to 4. 6. A spray nozzle is arranged in the vicinity of both opposite walls of the exhaust gas flow passage, and the spray momentums of the spray nozzles of adjacent spray stages are different for each spray stage on the same side wall surface. The wet flue gas desulfurization device according to any one of claims 1 to 5. 7. The spray nozzles having different spray momentums are configured such that the number of spray stages having spray nozzles having the same spray flow rate is different on the wall surfaces on both sides facing each other. The wet flue gas desulfurization apparatus according to. 8. A spray nozzle having spray nozzles arranged in the vicinity of opposite side walls of the exhaust gas passage, wherein the spray momentum of the spray nozzles of the spray stages arranged on one side wall surface is the spray stage arranged on the other side wall surface. The wet flue gas desulfurization apparatus according to any one of claims 1 to 7, wherein the spray flue gas desulfurization apparatus comprises a spray nozzle having a spray momentum different from that of the spray nozzle. 9. The position where the absorbing liquids jetted from the spray nozzles arranged near the side wall surfaces of the exhaust gas passage facing each other are changed for each spray stage, according to any one of claims 1 to 8. The wet flue gas desulfurization apparatus according to. 10. A spray nozzle is disposed in the vicinity of the wall surface of the exhaust gas flow passage, and at least one spray stage is installed in the gas flow direction of the exhaust gas flow passage to bring the absorbing liquid injected from the spray nozzle into contact with the exhaust gas. In the wet flue gas desulfurization apparatus for removing the sulfur oxides, at least one spray stage in which tower-installed spray nozzles are scattered on a surface orthogonal to the gas flow is installed in addition to the wall-mounted spray nozzle disposed near the wall surface. A wet flue gas desulfurization device characterized by: 11. The tower-installed spray nozzle is provided at the most downstream spray stage of the exhaust gas passage.
The wet flue gas desulfurization apparatus described. 12. The wet flue gas desulfurization apparatus according to claim 10, wherein the in-column installed spray nozzles are provided at the most upstream spray stage and the most downstream spray stage of the exhaust gas passage. 13. A spray stage in which a tower-installed spray nozzle is disposed is alternately disposed in a gas flow direction of the exhaust stage and a spray stage in which a spray nozzle disposed near a wall surface of the exhaust gas passage is disposed. The wet flue gas desulfurization apparatus according to claim 10. 14. The spraying direction of the absorbing liquid of the spray nozzle installed in the tower is directed to a countercurrent, a cocurrent or a combination of countercurrent and cocurrent with the flow direction of the exhaust gas. 14. The wet flue gas desulfurization device according to any one of 1 to 13. 15. An exhaust gas flow passage in which gas flows vertically or a horizontal direction, and an exhaust gas flow passage in which gas flows in a non-vertical direction is provided.
The wet flue gas desulfurization apparatus according to any one of 1.