JPH11319480A - Stack-integrated flue gas desulfurizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the condensed water flowing down on the inner wall surface of a stack from being blown up and rescattered and to remarkably reduce the mist contained in the discharged waste gas by positively collecting the mist in the waste gas. SOLUTION: A stack 2 is connected directly to the upper end of the absorption tower 1 internally provided with a spray nozzle 4 and a mist eliminator 7 to constitute this desulfurizer. In this case, a blast flange 16 is provided above the eliminator, a suction flange 17 is opposed to the blast flange 16, and the waste gas sucked from the suction flange 17 is jetted from the blast flange 16 to generate a spiral flow of the waste gas ascending in the absorption tower 1. Mist collecting troughs 23 and 24 are arranged respectively at a necessary position on the inner wall surface of the stack, and the mist in the spiral flow of the waste gas is collided with the inner surface of the stack while ascending in the stack and converted into a liq. drop which flows down on the inner wall surface and is collected in the troughs 23 and 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flue gas desulfurization apparatus for removing sulfur oxides contained in exhaust gas, and more particularly to a stack-integrated flue gas desulfurization apparatus.

[0002]

2. Description of the Related Art Exhaust gas from boilers and the like contains sulfur oxides, which cause air pollution such as acid rain. The oxide has been removed. As an industrial flue gas desulfurization device, there is a stack exhaust gas desulfurization device, in which an alkaline neutralizing agent is added to exhaust gas flowing through the chimney to perform desulfurization. A mist eliminator is provided inside the stack-integrated flue gas desulfurization device to remove the entrained mist generated in this desulfurization process.

Referring to FIG. 3, a conventional flue gas desulfurization apparatus integrated with a chimney will be described.

[0004] The stack-integrated flue gas desulfurization apparatus has a structure in which a stack 2 is connected to the upper end of an absorption tower 1.

In the lower part of the absorption tower 1, a storage part 3 for absorbing liquid is provided.
Is formed, and a large number of spray nozzles 4 are disposed above the storage section 3.
Thus, a circulation pump 6 is provided in the absorption liquid supply pipe 5. A mist eliminator 7 for collecting mist in the exhaust gas is provided above the spray nozzle 4 and near the outlet of the storage unit 3.

The mist eliminator 7 is formed by laminating a large number of thin plates bent in a zigzag shape with a predetermined gap provided therebetween, and traps entrained mist in the exhaust gas by passing through the narrow gap where the exhaust gas is bent. Gathering.

[0007] Exhaust gas that has passed through a flue (not shown) from a coal-fired boiler or the like and that has been sent from the exhaust gas inlet 8 to the absorption tower 1 comes into contact with the absorbing liquid sprayed from the spray nozzle 4 to thereby oxidize sulfur. object (S0 ₂₎ is absorbed and removed. Further, entrained mist contained in the exhaust gas is removed in the process of passing through the mist eliminator 7, and rises up the chimney 2 and is discharged to the atmosphere.

Further, the exhaust gas that has exited the absorption tower 1 contains a certain amount of moisture, and the moisture adheres to the inner wall surface of the chimney 2 and flows down as condensed water 9 to increase the flow rate of the exhaust gas. At the connection between the absorption tower 1 and the chimney 2,
In some cases, the condensed water 9 was blown up by the rising exhaust gas and scattered again, and scattered as mist from the upper end of the chimney to the surroundings. For this reason, a bottomed ring-shaped receiving member 10 is attached to the upper end of the chimney 2, and the mist collected by the receiving member 10 is collected by the drain tube 11 into a storage part. Returned to 3.

[0009]

However, the receiving member 1 described above.
0 is not a fundamental solution that the condensed water 9 flowing down the inner wall surface of the chimney 2 is blown up and re-scattered, and the receiving member 10 captures a relatively large mist of particles that are sprayed from the upper end of the chimney 2. It can, but cannot capture small mist of particles or mist flowing out with exhaust gas.

Furthermore, in order to completely remove the mist in the exhaust gas, it is necessary to increase the mist collection rate of the mist eliminator 7. However, when the collection rate is increased, the pressure loss in the mist eliminator 7 becomes large. Therefore, there is a problem that a predetermined flow rate of the exhaust gas cannot be obtained, and it has been difficult to sufficiently remove the mist from the exhaust gas discharged from the chimney 2. Further, the temperature of the exhaust gas discharged from this type of stack-integrated flue gas desulfurization device is approximately 50 ° C.
Water vapor condenses and forms a mist, but it is more difficult to remove sulfide and water vapor condensed in the chimney.

In view of such circumstances, the present invention prevents condensed water flowing down the inner wall surface of a chimney from being blown up and re-scattered, and also actively collects mist in the exhaust gas and discharges the exhaust gas. It is intended to significantly reduce the mist contained in the mist.

[0012]

SUMMARY OF THE INVENTION The present invention relates to a stack-integrated flue gas desulfurization apparatus in which a chimney is connected to the upper end of an absorption tower provided with a spray nozzle and a mist eliminator therein. A pushing flange is provided at a position above the mist eliminator, and a suction flange is provided opposite to the pushing flange. Exhaust gas sucked from the suction flange is ejected from the pushing flange to generate a swirl flow in the exhaust gas rising in the absorption tower. The present invention relates to a stack-integrated flue gas desulfurization device provided with a mist collecting gutter at a required position on the inner wall surface of the chimney, and the direction of suction from the suction flange and the direction of ejection from the pushing flange are tangent to the wall surface of the absorption tower. The invention relates to a stack-integrated flue gas desulfurization device, wherein the suction flange is located below the pushing flange. In the process of raising the chimney by giving a swirl flow to the exhaust gas, mist in the exhaust gas collides with the inner wall surface of the chimney to form droplets, flows down the inner wall surface of the chimney and is collected by the mist collecting gutter. .

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows a main part of the present embodiment. In FIG. 1, the same components as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

A chimney 2 is connected to the upper end of the absorption tower 1, and the diameter of the chimney 2 in the upper half is smaller than that in the lower half. Further, a junction 1a between the absorption tower 1 and the chimney 2 and a junction 2a between the lower half and the upper half of the chimney 2 are tapered.

The mist eliminator 7 of the absorption tower 1
Above the swirl flow generator 1 below the joint 1a.
5 are provided.

The swirling flow generator 15 will be described with reference to FIG.

In the tangential direction of the outer circumference of the absorption tower 1
6. The suction flanges 17 are provided so as to face each other, and the position of the suction flange 17 in the vertical direction with respect to the pushing flange 16 is on the lower side. Another pair of the pushing flange 18 and the suction flange 19 are provided opposite to each other with respect to the pushing flange 16, the suction flange 17 and the center of the absorption tower 1.

One set of pushing flanges 16 and the other set of suction flanges 19 communicate with each other via a swirling flow generating blower 21, and one set of suction flanges 17 and the other set of pushing flanges 18 are connected to one another. The two swirling flow generating blowers 22 communicate with each other. Thus, the swirling flow generating blower 21 and the swirling flow generating blower 22 suck the exhaust gas in the absorption tower 1 from the suction flange 17 and the suction flange 19, respectively, and enter the absorption tower 1 from the pushing flange 16 and the pushing flange 18. Gushing.

On the lower inner wall surface of the lower half of the chimney 2 and over the joint 1a, the first mist collecting gutter 23 extends all around.
In addition, a second mist collecting gutter 24 is provided on the lower inner wall surface of the upper half portion of the chimney 2 and above the joint portion 2a over the entire circumference. A mist drain pipe 25 communicates with the second mist collection gutter 24 and the first mist collection gutter 23, and a lower end of the mist drain pipe 25 communicates with the storage unit 3.

Hereinafter, the operation will be described.

Exhaust gas that has passed through a flue (not shown) from a coal-fired boiler or the like and has been sent to the absorption tower 1 from an exhaust gas inlet 8 comes into contact with the absorbing liquid sprayed from the spray nozzle 4 to thereby oxidize sulfur. object (S0 ₂₎ are absorbed and removed, it passes through the mist eliminator 7. The mist eliminator 7
Most of the mist contained in the exhaust gas is removed in the process of passing through.

As described above, the swirl flow generating blower 21
The exhaust gas is sucked from the suction flange 19, and the sucked exhaust gas is ejected from the pushing flange 16. Similarly, the exhaust gas is sucked from the suction flange 17 by the swirling flow generating blower 22, and the sucked exhaust gas is sucked into the pushing flange 18. The two tangential flows are formed to blow out along the inner wall surface inside the absorption tower 1, and the tangential flows generate a swirling flow 27 counterclockwise in FIG. 2 inside the absorption tower 1.

As described above, the pushing flanges 16, 18
The positions of the suction flanges 17 and 19 are shifted to the lower side, and the exhaust gas in the absorption tower 1 further rises, so that the gas sucked from the suction flanges 17 and 19 is ejected from the pushing flanges 16 and 18. Is different from the gas used. Therefore, the swirling flow can be effectively generated for the rising exhaust gas by ejecting and sucking the gas. For the same reason, the pushing flange 16 and the pushing flange 18 and the suction flange 17 and the suction flange 19 may be shifted vertically.

The swirling flow 27 is increased in speed by the exhaust gas flow being throttled by the joint 1a, and becomes a high-speed swirling flow.
A further high-speed swirling flow is obtained by further narrowing down by the joint 2a. The entrained mist generated in the desulfurization process and the mist condensed in the chimney by the swirling flow 27 collide with the inner wall surface of the chimney 2. The mist is turned into droplets by collision and condensed water 9
As a result, the gas flows down the inner wall surface of the chimney 2, is collected by the first mist collection gutter 23 and the second mist collection gutter 24, and is further returned to the storage unit 3 from the mist drain pipe 25. Thus, exhaust gas from which mist has been sufficiently removed is discharged from the chimney 2.

The condensed water 9 is supplied to the second mist collecting gutter 2
4. Since the water is collected by the first mist collecting gutter 23, the condensed water 9 is blown up by the rising exhaust gas at the connection between the absorption tower 1 and the chimney 2 as in the related art. No re-scattering.

In the above embodiment, two sets of suction flanges and push-in flanges are provided, but one set or three or more sets may be provided. Further, although the diameter of the chimney 2 is set to two steps and the joint 2a is provided in the middle, the diameter of the chimney 2 is set to one step and the joint 2a is not necessarily provided. Furthermore, the number of mist collecting gutters may be one, or three or more.

The above-mentioned swirling flow generator 15 is provided with the chimney 2
Since it is installed from outside, the existing stack-integrated flue gas desulfurization unit can be equipped with additional equipment, and can be modified or added even during operation of the equipment.

[0029]

As described above, according to the present invention, a swirl flow can be imparted to the exhaust gas rising in the chimney without causing a pressure loss, so that mist in the exhaust gas can be effectively collected and the exhaust gas discharged The device that can significantly reduce the mist contained in the gas and add the swirl flow can be added to the existing stack-integrated flue gas desulfurization device, and it is possible to perform additional work during operation. Demonstrate.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a main part of an embodiment of the present invention.

FIG. 2 is a schematic diagram of a swirling flow generator provided in the embodiment.

FIG. 3 is a schematic view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Absorption tower 2 Chimney 4 Spray nozzle 7 Mist eliminator 15 Swirling flow generator 16 Pushing flange 17 Suction flange 18 Pushing flange 19 Suction flange 23 1st mist collection gutter 24 2nd mist collection gutter 25 Mist drain pipe 27 Swirl flow

Claims (3)

[Claims] 1. A stack-integrated flue gas desulfurization system in which a chimney is connected to an upper end of an absorption tower provided with a spray nozzle and a mist eliminator therein, and is pushed into a position above the mist eliminator in the absorption tower. A flange is provided and a suction flange is provided opposite to the pushing flange. Exhaust gas sucked from the suction flange is blown out from the pushing flange to generate a swirl flow in the exhaust gas rising in the absorption tower, and the required chimney inner wall surface is formed. A stack-integrated flue gas desulfurization device characterized by providing a mist collecting gutter at a position. 2. The stack-integrated flue gas desulfurization apparatus according to claim 1, wherein a suction direction from the suction flange and a jetting direction from the pushing flange are tangential to a wall surface of the absorption tower. 3. The flue gas desulfurization apparatus integrated with a chimney according to claim 1, wherein the suction flange is located below the pushing flange.