JPH06154549A - Semi-dry desulfurization device - Google Patents

Abstract

PURPOSE:To prevent desulfurization efficiency from deteriorating by ensuring that a gas spews out from the inner chamber of an evaportizative reaction tower at the same flow speed as that of the gas during a full operation and slaked lime slurry sprayed from a rotary atomizer disc is mixed at the same rate as that during the full operation. CONSTITUTION:A rotary atomizer disc 10 which atomizes slaked lime slurry and a rotary blade 12 are provided in a evaporative reaction tower 5 consisting of an inner chamber 4 and an outer chamber 5. In addition, there are provided a main flue 2 which supplies an exhaust gas from a flue 1 to the inner chamber 4 and a branched flue 3 which supplies the exhaust gas to the outer chamber 5. Further, a first small-dia pipe 8 with the other end which is open into the inner chamber 4 and a pressure adjustment valve 14, is provided in the flue 2 near a branch point for the flues 2, 3. A second small-dia. pipe 9 which is open into the space of a negative pressure tower 6 with the other relatively smaller end and runs through the rear chamber of vortex-type fluid element 16 which is divided as a front chamber 17 and a rear chamber 18 by a disc 19 having an concentric opening halfway through, is provided in the flue 3. Finally, a third small-dia. pipe 15 which supplies an exhaust gas tangentially is provided in the front chamber 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention brings exhaust gas into contact with mist of slaked lime slurry to remove sulfur oxides (hereinafter referred to as SO
(abbreviated as x) is a semi-dry type desulfurization device for removing the semi-dry type.

[0002]

2. Description of the Related Art In a semi-dry desulfurization apparatus, for example, as shown in FIG. 4, exhaust gas from a boiler 1 passes through an air heater 2 and enters an evaporation reaction tower 3 where it reacts with the spray of slaked lime slurry to produce SOx (SO ₂ , SO ₃ ) is absorbed by the spray droplets, and at the same time, the droplets are evaporated by the heat of the exhaust gas to become dry particles, and the reaction products are collected and removed together with the fly ash by the electrostatic precipitator 4, SOx, The flue gas from which the fly ash has been removed is discharged from the chimney 5 to the atmosphere.

A partial perspective view of the evaporation reaction tower 3 is shown in FIG.
FIG. 6 shows an enlarged cross-sectional view of FIG. In FIGS. 5 and 6, the exhaust gas entering the evaporation reaction tower 3 becomes a swirling flow by the swirl vanes 12, and reacts with the slaked lime slurry sprayed from the rotary atomizer 10 rotated at a high speed by the motor 11 to convert SOx in the exhaust gas into CaSO _4. Collect and desulfurize. In the figure, 13 is a flow guide plate.

Boiler exhaust gas is introduced into the apparatus through a single flue, and the gas introduction section including the swirl flow generating apparatus in the apparatus is also single. However, if there are multiple rotary atomizers and there are multiple gas inlets, they will still exist. That is, conventionally, there is one rotary atomizer and one gas inlet.

[0005]

In the conventional apparatus shown in FIGS. 5 and 6, when the amount of exhaust gas decreases in accordance with changes in the operating conditions of the plant, the flow velocity of the gas swirled into the apparatus decreases and the amount of gas The turning strength becomes smaller. In this case, the momentum of the gas becomes weak and the mixing with the mist of the slaked lime slurry sprayed from the rotary atomizer becomes poor, so that the desulfurization reaction rate becomes poor.

In view of the above-mentioned state of the art, the present invention is to provide a semi-dry desulfurization apparatus which is well mixed with slaked lime slurry mist and can prevent the reduction of desulfurization efficiency even if the amount of exhaust gas is reduced.

[0007]

DISCLOSURE OF THE INVENTION The present invention is an evaporation reaction tower having a rotary atomizer disk for spraying slaked lime slurry and a swirl vane, which is divided into an inner chamber and an outer chamber. Main flue supplied to the inner chamber of the reaction tower and branch flue supplied to the outer chamber The other end of the main flue and the main flue near the branch point of the branch flue is the inner chamber of the evaporation reaction tower First small-bore pipe provided with a pressure control valve, and the other end provided in the branch flue near the branch point is opened to the space of the evaporation reaction column having a relatively small negative pressure, and Vortex fluid element divided into a front chamber and a rear chamber by a disc having a concentric opening on the way. Second small-diameter tube passing through the rear chamber. The vortex fluid element provided in the main flue. A semi-small diameter pipe for supplying exhaust gas to the front chamber of It is an expression desulfurization unit. An embodiment of the semi-dry desulfurization apparatus of the present invention will be described below with reference to the drawings, and the configuration and operation of the present invention will be specifically described.

[0008]

1 is a plan view of an embodiment of a semi-dry desulfurization apparatus of the present invention, and FIG. 2 is a side view of the same. 1 and 2 in FIG.
Is a flue, 2 is a main flue, 3 is a branch flue, 4 is an inner chamber of an evaporative reaction tower described later, 5 is the same outer chamber, 6 is an evaporative reaction tower, and 7 is a flue 1
, 8 is a first small diameter pipe, 9 is a second small diameter pipe,
10 is a rotary atomizer disk, 11 is a motor, 1
2 is a swirl vane, 13 is a flow guide plate, 14 is a pressure regulating valve, 15 is a third small diameter pipe, 16 is a vortex type fluid element, 17 is a front chamber of the same element, 18 is a rear chamber of the same element, 19 Is a disk having an opening of the same element. The slaked lime slurry supply device is omitted in the figure.

The flue 1 has a branch point 7 and a main flue 2 and a branch flue 3
The main flue 2 is connected to the inner chamber 4 of the evaporation reaction tower 6, and the branch flue 3 is connected to the outer room 5 of the tower 6. The exhaust gas flowing from each flue 2, 3 through the inner chamber 4 and the outer chamber 5 into the evaporation reaction tower 6 is swirled by the swirl vanes 12, but the introduction direction and angle can be changed by the flow guide plate 13. Is preferred. The exhaust gas introduced into the evaporation reaction tower 6 in this way is fed to the motor 11
Is supplied onto the rotary atomizer disk 10 driven at a high speed of 10 ³ to 10 ⁵ rpm, and brought into contact with the atomized slaked lime slurry to desulfurize the exhaust gas.

The operation of the device of the present invention will be described below. In the device of the present invention, of the exhaust gas flowing through the flue 1, for example, half of the exhaust gas of full load passes through the main flue 2 regardless of the load, and the evaporative reaction from the inner chamber 4 of the evaporative reaction tower 6 is always a fixed amount. It is installed so as to be supplied to the tower 6, and further exhaust gas is supplied to the evaporation reaction tower 6 from the outer chamber 5 of the evaporation reaction tower 6 through the branch flue 3. To divide the exhaust gas from the flue 1 into the main flue 2 and the branch flue 3, see Pra in Figure 3.
This is done by utilizing the effect of the ndtl diffuser and the vortex type fluid element described later.

In FIG. 3, the fluid flowing into the diffuser becomes an unstable flow unless controlled as shown in FIG. 3A, and flows in any direction as shown by the arrow. However, when a small amount of suction is performed from one side of the diffuser as shown in FIG. 3B, the fluid flowing into the diffuser becomes a stable flow adhering to the suctioned side. Further, when sucked from both sides as shown in FIG. 3 (c), the fluid becomes a stable flow adhering to both sides. The device of the present invention utilizes this principle to divide the exhaust gas flow into the main flue 2 and the branch flue 3.

For this reason, a first small-diameter pipe having an open end from the main flue 2 at the flue branch point 7 and the other end opening into the inner chamber 4 of the evaporation reaction tower 6 under a large negative pressure condition. Set up 8, Prandt
By the principle of the diffuser l, the exhaust gas from the flue 1 is made to flow mainly to the main flue 2 side.

Next, the division of the exhaust gas to the side of the branch flue 3 by utilizing the action of the vortex type fluid element will be described. Figure 1,
As shown in FIG. 2, the vortex flow type fluid element 16 is such that the front chamber 17 and the rear chamber 18 are partitioned by a disc 19 having concentric openings. From the middle of the main flue 2 to the third small diameter tube 1
5 is branched and exhaust gas is caused to flow into the evaporation reaction tower 6 through the vortex type fluid element 16. Eddy current type fluid element 16
The exhaust gas enters the front chamber 17 from the tangential direction of its circumference, swirls, and flows out to the rear chamber 18 through the disc 19. A second small-diameter pipe 9 having an open end on the side of the branch flue 3 of the branch 7 of the flue is connected to the rear chamber 18 of the swirl type fluid element 16. When the amount of exhaust gas flowing through the main flue 2 is small, the amount of exhaust gas passing through the swirl type fluid element 16 from the third small diameter pipe 15 is small, and the swirl type fluid element 16
Since the fluid resistance is small, and the suction force at the branch point 7 of the flue of the second small diameter pipe 15 is also small, the amount of exhaust gas flowing into the flue 3 is small. However, when the amount of exhaust gas passing through the main flue 2 increases, the fluid resistance loss of the vortex flow type fluid element 16 increases, and as a result, the suction force by the second small diameter pipe 9 at the branch point 7 of the flue increases. A large amount of exhaust gas also flows into the branch flue 3. In this way, the main flue 2 is set so that, for example, half of the exhaust gas amount of full load always passes, and the remaining flue gas is set to flow to the branch flue 3.

If the suction through the first small-diameter pipe 8 is too large, a large amount of exhaust gas flows to the side of the branch flue 2, so that the first small-diameter pipe 8 is provided with a pressure adjusting valve 14 and the suction force is increased. To adjust.

[0015]

The present invention has the following effects. (1) Even if the exhaust gas flow rate decreases, the gas flow velocity ejected from the inner chamber is the same as that during full operation, and mixing of slaked lime slurry sprayed from the rotary atomizer disk is the same as during full operation, resulting in a decrease in desulfurization efficiency. Can be prevented. (2) As the flow rate of exhaust gas increases, gas inflow from the outer chamber automatically occurs, and no artificial control is required. (3) In the process from half load to full load, even if the gas velocity flowing out of the outer chamber is smaller than that at full load,
Exhaust gas emitted from the inner chamber has a strong momentum, and the amount from the outer chamber is mixed with this, so the effect of efficiency reduction is small.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of a semi-dry desulfurization apparatus of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is an explanatory diagram of a diffuser of Prandle.

FIG. 4 is a schematic diagram of a conventional semi-dry desulfurization process.

FIG. 5 is a partially cutaway perspective view of a conventional evaporation reaction tower.

FIG. 6 is a side view of a conventional semi-dry desulfurization apparatus.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takao Yanagida 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries Ltd. Kobe Shipyard

Claims (1)

[Claims] 1. An evaporation reaction tower which is equipped with a rotary atomizer disk for spraying slaked lime slurry and a swirl vane and is divided into an inner chamber and an outer chamber. The smoke-conducting exhaust gas from an exhaust gas source is supplied to the inner chamber of the evaporation reaction tower. Main flue and branch flue to supply to the outer chamber The other end of the main flue and the main flue near the branch point of the branch flue is open to the inner chamber of the evaporative reaction tower and the pressure is adjusted. First small-diameter pipe provided with a valve The other end provided in the branch flue near the branch point opens into the space of the evaporation reaction column having a relatively small negative pressure, and a concentric opening partway Second small-caliber tube that passes through the rear chamber of the vortex-type fluid element divided into a front chamber and a rear chamber by a disc having a cross section in the front direction of the front chamber of the vortex-type fluid element provided in the main flue. A semi-dry desulfurization apparatus comprising a third small diameter pipe for supplying exhaust gas.