JPH04686B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hydrogen chloride removal device for removing hydrogen chloride by blowing lime powder into exhaust gas containing hydrogen chloride exhausted from an incinerator or the like. .

[Conventional technology]

The incineration exhaust gas emitted from the incinerator is caused by the thermal decomposition of PVC plastics contained in the incinerated materials.
Contains 600-1000ppm hydrogen chloride.

Conventionally, this hydrogen chloride has been removed by injecting lime powder such as slaked lime or quicklime into the exhaust gas, but this has the problem of a low removal rate due to insufficient contact between the exhaust gas and lime powder. be.

For this reason, hydrogen chloride is removed from the exhaust gas by passing it through a moving packed bed of quicklime or the like.
That is, a punched plate, a screen, or a louver is placed facing the exhaust gas flow, and quicklime is filled in between and circulated downward to form a moving packed bed, and the packed bed removes hydrogen chloride. I have to.

[Problem that the invention seeks to solve]

However, the exhaust gas from the incinerator contains a large amount of dust, and if this is allowed to flow directly into the moving packed bed, it will clog the screens, increase pressure loss, and cause the dust in the moving packed bed to clog. This causes problems such as quicklime not flowing.

For this reason, an electrostatic precipitator is installed at the front stage to allow the exhaust gas after dust removal to flow through the moving packed bed, but when the flue gas passes through the moving packed bed, fine powder such as quicklime is scattered into the flue gas. Therefore, it is necessary to install an electrostatic precipitator again downstream, which raises the problem of high costs.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a hydrogen chloride removal device with low pressure loss and high hydrogen chloride removal rate.

[Means and actions for solving problems]

In order to achieve the above object, the present invention provides hydrogen chloride that blows lime powder into combustion exhaust gas containing hydrogen chloride discharged from an incinerator, etc., and removes the lime powder that has reacted with the hydrogen chloride from the flue gas. In the removal device, a moving layer made of a carrier such as sand is formed to move in the direction of gravity so as to be transverse to the flow of the exhaust gas and capture the lime powder. Louvers are provided at intervals, the front and rear louvers are shifted vertically relative to each other, each louver is tilted downward from the center of the moving layer, and the carriers of the moving layer are alternately held and moved by the front and rear louvers. First, lime powder is blown into the exhaust gas, and lime powder that has reacted with hydrogen chloride is blown into the exhaust gas.
Lime powder that has reacted with hydrogen chloride is captured in a moving bed, and the removal rate of hydrogen chloride is increased by flowing exhaust gas through the moving bed, and the front and rear louvers are placed close to each other, and the front and rear louvers are staggered vertically. This allows the carrier to be moved downward while being held by the front and rear louvers, ensuring good contact with exhaust gas and preventing clogging due to dust and the like.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, a preferred embodiment of the hydrogen chloride removal apparatus according to the present invention will be described based on the accompanying drawings.

In Figure 1, 1 is an incinerator such as a fluidized bed;
A gas cooling device 2 is connected to the exhaust gas outlet, and a hydrogen chloride removal device 4 is connected to the downstream side via a duct 3, and further an electrostatic precipitator 5 and an induced blower 6
A chimney 7 is connected to the garbage incinerator plant through the chimney 7.

A duct 3 leading from the gas cooling device 2 to the hydrogen chloride removal device 4 is supplied with lime powder for injecting lime powder such as slaked lime (Ca(OH) ₂ ) and quicklime (CaO) into the exhaust gas passing through the duct 3. Device 8 is connected.

This lime powder supply device 8 includes a hopper 9 that discharges lime powder, a blower 10 that supplies conveying air,
The conveyor line 11 is connected to the duct 3.

As shown in FIG. 2, the hydrogen chloride removal device 4 consists of a casing 12 into which the exhaust gas into which lime powder has been blown is introduced. A moving layer 14 made of granular carriers 13 is formed.

That is, a front louver 15 is provided on the front side of the moving layer 14, and a rear louver 16 is provided on the rear side, and a granular carrier 13 such as silica sand, limestone, slag, or cement clinker is filled between them to form the moving layer 14. Ru.

The front and rear louvers 15 and 16 are connected to the casing 12
are provided at predetermined intervals along the vertical direction, and a front louver 15 and a rear louver 1, respectively.
6 are provided so as to be shifted from each other. Further, each of the louvers 15 and 16 is inclined so as to face downward from the center of the moving layer 14, and is provided so that the front and rear louvers 15 and 16 are close to each other.

At the top of the casing 12, there are front and rear louvers 1.
A hopper 17 for supplying granular carrier 13 is provided between 5 and 16, and a louver 1 is provided at the bottom.
The granular carrier that has descended between 5 and 16 is transferred to the casing 12
rotor 1 for discharging to the hopper 18 at the bottom of the
9 is provided.

As shown in FIG. 1, the granular carriers 13 and the like accumulated in the lower hopper 18 are discharged to a classifier 20, where lime powder and dust are separated from the granular carriers 13, and the granular carriers 13 are transported to the upper part via a vertical conveyor 21. The water is circulated to the hopper 17.

In the above, from the incinerator 1, incineration exhaust gas containing hydrogen chloride is exhausted due to the thermal decomposition of PVC plastics contained in the incinerated material, and the gas cooling device 2
After the heat is recovered, it flows into duct 3.
Lime powder is blown into the duct 3 from a lime powder supply device 8, and this lime powder reacts with hydrogen chloride in the exhaust gas to become calcium chloride and remove the hydrogen chloride.

While the exhaust gas into which lime powder has been blown passes through the moving bed 14 of the hydrogen chloride removal device 4, the lime powder and ducts in the exhaust gas are captured by the granular carrier 13 that descends through the moving bed 14, and then transferred to an electrostatic precipitator. After the dust is removed in step 5, it is exhausted from the chimney 7 via an induced blower 6.

As described above, the exhaust gas containing lime powder that has entered the hydrogen chloride removal device 4 passes between the front louvers 15 , passes through the moving layer 14 , and passes through the rear louver 16 . Lime powder and ducts are captured in the moving layer 14, but unreacted hydrogen chloride in the exhaust gas is trapped in the moving layer 14 while passing through the moving layer 14.
If lime powder trapped inside or limestone is used as the granular carrier 13, it will react with the limestone.
The removal rate of hydrogen chloride can be increased.

Further, the granular carriers descending on the moving layer 14 are
As shown in the figure, since the front and rear louvers 15 and 16 are arranged close to each other and shifted vertically from each other, they descend as shown by the arrows while alternately colliding with the front louver 15 and the rear louver 16. Because of the movement, the moving layer 14 is not compacted, and therefore the pressure loss of the exhaust gas passing through the moving layer 14 can be reduced.

Furthermore, as shown in FIG. 3, the front and rear louvers 15, 16 have an inclination α of around 60 degrees, and a distance L between the upper and lower louvers 15, 16 of 100 degrees.
By keeping the distance d between the tips of the louvers 15 and 16 in the range of -5 to 25 mm, lime powder and dust can be captured well and a moving layer 14 with low pressure loss can be formed.

Furthermore, the moving layer 14 can adjust the speed at which the granular carrier 13 is discharged by the rotor 19 below.
The descending speed of the moving layer 14 can be adjusted.

〔Effect of the invention〕

As is clear from what has been described in detail above, the present invention exhibits the following excellent effects.

(1) The removal rate of hydrogen chloride can be increased by blowing lime powder into the exhaust gas containing hydrogen chloride and trapping the lime powder and dust in the exhaust gas through a moving layer of carrier formed by louvers.

(2) By placing the front and rear louvers close to each other and shifting the positions of the front and rear louvers, the carriers in the moving bed can be lowered while being alternately held by the front and rear louvers, so the moving bed is not consolidated and the pressure loss of exhaust gas is reduced. can be reduced.

[Brief explanation of drawings]

FIG. 1 is an overall view showing one embodiment of the present invention, and FIG.
The figure is an enlarged sectional view of the main part of FIG. 1, and FIG. 3 is a diagram showing details of the louver shown in FIG. 2. In the figure, 1 is an incinerator, 3 is a duct, 4 is a hydrogen chloride removal device, 8 is a lime powder supply device, 13 is a carrier, 1
4 is a moving layer, 15 is a front louver, and 16 is a rear louver.

Claims (1)

[Claims] 1 In a hydrogen chloride removal device that blows lime powder into combustion exhaust gas containing hydrogen chloride exhausted from an incinerator, etc., and removes the lime powder that reacts with hydrogen chloride from the exhaust gas, A moving layer made of a carrier such as sand is formed to move in the direction of gravity so as to capture the lime powder, and louvers are provided at a predetermined interval above and below on both sides of the moving layer, and louvers before and after the moving layer are provided. The louvers are vertically shifted relative to each other, and each louver is tilted downward from the center of the moving layer, and the carriers of the moving layer are alternately held and moved by the front and rear louvers so as to be close to each other. Hydrogen removal equipment.