JP2000283449A - Exhaust gas treating method and facility having white smoke prevention function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of devices and reduce equipment cost. SOLUTION: Cooling-and-diluting air is blown for cooling and dilution of moisture from a white smoke preventing fan into a mixing device 24 into which exhaust gas is introduced from an incinerator 22 via a heat recovery boiler 23, and the exhaust gas discharged from the mixing device 24 is introduced into a bag filter 25 so as to remove soot and a hazardous substance, and the exhaust gas inducted from the bag filter 25 by an induction fan 26 is emitted from a flue 27 into the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas treatment method and equipment installed in an incinerator for municipal waste and industrial waste and having a function to prevent white smoke.

[0002]

2. Description of the Related Art For example, conventional exhaust gas treatment equipment having a function to prevent white smoke is shown in FIGS. FIG.
In the conventional exhaust gas treatment equipment A shown in FIG. 1, the exhaust gas discharged from the incinerator 1 is introduced into the heat recovery boiler 2 to recover heat, and then the exhaust gas (temperature of about 470 ° C., moisture 29%) from the boiler 2 is converted to a gas type. The white smoke prevention air supplied from the white smoke prevention fan 11 introduced into the air preheater 3 is heated by the exhaust gas. Exhaust gas (temperature about 300 ° C., moisture 29%) discharged from the gas type air preheater 3 is
Will be introduced. In the temperature control tower 4, the cooling water pump 1
The cooling water supplied from 2 is preheated by the hot air from the purge hot air fan 13 and pressurized by the compressed air from the air compressor 14 to be sprayed into the exhaust gas to cool the exhaust gas. Next, the exhaust gas (temperature: about 180 ° C., water content: 32%) discharged from the temperature control tower 4 is added to a treating agent and the like, and then introduced into the bag filter 5 to remove dust and harmful substances (chloride) in the exhaust gas. , Sulfides, heavy metals, etc.) are removed. Further, the exhaust gas is introduced into the mixer 7 from the bag filter 5 via the attraction fan 6, and the white smoke prevention air sent from the gas air preheater 3 is mixed with the exhaust gas, so that the exhaust gas is released into the atmosphere. The temperature is adjusted to a range (for example, a temperature of about 170 ° C. and a water content of 17%) in which no white smoke is generated when the gas is discharged from the chimney 8 to the atmosphere. Reference numeral 15 denotes a collection conveyor for discharging dust and the like collected by the gas air preheater 3 and the temperature control tower 4.

[0003] In the conventional exhaust gas treatment equipment B shown in FIG. 3, the exhaust gas discharged from the incinerator 1 is heat-recovered through the heat recovery boiler 2 and then introduced into the gas air preheater 3. The white smoke prevention air supplied from the white smoke prevention fan 11 is introduced into the gas air preheater 3 after the heat source steam is heated by the steam type air preheater 14 supplied from the boiler 2. The heat is recovered from the exhaust gas into white smoke prevention air. And after the treatment agent is added to the exhaust gas,
The exhaust gas is introduced into the bag filter 5 to remove dust and harmful substances (chloride, sulfide, heavy metal, etc.) in the exhaust gas. Further, the exhaust gas from the bag filter 5 is introduced into the mixer 7 via the induction fan 6. In the mixer 7, white smoke preventing air is introduced through the gas air preheater 3 and mixed with the exhaust gas, and is adjusted to a temperature and a moisture value that do not generate white smoke when released into the atmosphere. You. Then, it is released from the chimney 8 into the atmosphere.

[0004] In the conventional exhaust gas treatment equipment C shown in FIG. 4, the exhaust gas discharged from the incinerator 1 is recovered into heat via the heat recovery boiler 2 and then introduced into the temperature control tower 4. In the temperature control tower 4, cooling water supplied from a cooling water pump 12 is preheated by hot air from a purging hot air fan 13 and pressurized by compressed air from an air compressor 14, and sprayed into exhaust gas. Then, the exhaust gas is cooled. Then, after a treatment agent or the like is added to the exhaust gas, the exhaust gas is introduced into the bag filter 5 to remove dust and harmful substances (chloride, sulfide, heavy metal, etc.) in the exhaust gas. Further, the exhaust gas from the bag filter 5 is passed through the induction fan 6 to the mixer 7.
Will be introduced. The mixer 7 includes a white smoke prevention fan 1.
The white smoke prevention air supplied from 1 is heated and introduced through a steam type air preheater 14 using the steam of the boiler 2 as a heat source, and the white smoke prevention air is mixed with the exhaust gas. Thus, the exhaust gas is adjusted to a temperature and a moisture value at which white smoke is not generated when the exhaust gas is released to the atmosphere, and is discharged from the chimney 8 to the atmosphere.

[0005]

However, in the above-mentioned conventional configuration, there is a problem that the number of devices is large and the equipment cost is increased. An object of the present invention is to solve the above problems and to provide an exhaust gas treatment method and equipment having a white smoke prevention function that can reduce the number of devices and reduce equipment costs.

[0006]

According to a first aspect of the present invention, there is provided an exhaust gas treatment method having a function to prevent white smoke, wherein an exhaust gas discharged from an incinerator is introduced into a boiler to recover heat. The exhaust gas discharged from the boiler is introduced into a mixer, and the air is also cooled and diluted by blowing air for cooling and dilution, and the exhaust gas discharged from the mixer is introduced into a bag filter to remove dust and harmful substances. After removing the gas, the exhaust gas is attracted and discharged into the atmosphere.

According to a second aspect of the present invention, there is provided an exhaust gas treatment system having a function to prevent white smoke, wherein a boiler for introducing exhaust gas discharged from an incinerator and recovering heat, and cooling and dilution by introducing exhaust gas discharged from the boiler. A mixer that blows combined air to cool the exhaust gas, a bag filter that removes dust and harmful substances by introducing the exhaust gas discharged from this mixer, and discharges the exhaust gas discharged from this bag filter to the atmosphere. And an inducing fan.

[0008] According to the above-described structure, the mixer is disposed on the inlet side of the bag filter and the cooling and dilution air is blown into the exhaust gas to cool the bag filter to a temperature suitable for the bag filter and dilute the moisture value. White smoke when released into the atmosphere can be prevented. Therefore, although the exhaust gas capacity in the bag filter, the induction fan, and the exhaust gas passage on the downstream side is increased, the equipment and the like can be reduced as compared with the conventional exhaust gas treatment equipment having a white smoke prevention function, and Even if the increase is subtracted, the equipment cost can be significantly reduced. Also, by reducing the number of devices, the occupied volume can be reduced, and the size can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an embodiment of an exhaust gas treatment equipment according to the present invention will be described with reference to FIG. In FIG. 1, reference numeral 21 denotes an exhaust gas line for treating exhaust gas from a refuse incinerator, and a heat recovery boiler 23, a mixer 24, a bag filter 25, and an attraction fan 26 in order from an exhaust gas outlet of the incinerator 22.
And a chimney 27 are arranged.

In the exhaust gas line 21, the exhaust gas discharged from the boiler 23 is introduced into the mixer 24 at a temperature of about 300 ° C. and a moisture value of about 29%, for example. Cooling and dilution air is mixed. This cooling / dilution air is for cooling the exhaust gas and diluting the water (reducing the water value). For example, the water value is about 0.4% at about 5 ° C.
The supply amount is controlled according to the moisture value and the flow rate of the exhaust gas and the moisture value of the cooling / dilution air so that the exhaust gas temperature to the exhaust gas 5 is about 180 ° C. and the moisture value is about 17%. Note that an air drying device may be loaded on the white smoke prevention fan 28 according to the condition of the cooling and dilution air.

For example, if the amount of exhaust gas from the incinerator 22 is 16
In the case of 000 Nm ³ / h, the amount of air for cooling and dilution from the white smoke prevention fan 28 is 11500 Nm ³ / h. Therefore, the amount of exhaust gas introduced into the bag filter 25 is 27500 Nm ³ / h, and the exhaust gas discharged from the chimney 27 after passing through the bag filter 25 has a temperature of 170 ° C. and a moisture value of about 17%. In particular, white smoke can be prevented in the early morning and evening when the atmospheric temperature is low, and in cold regions.

In the above configuration, the exhaust gas discharged from the incinerator 22 is heat-recovered by the boiler 23 in the exhaust gas line 21, then introduced into the mixer 24 and supplied from the white smoke prevention fan 28 for cooling and dilution. It is cooled by air, cooled to about 180 ° C. suitable for the next bag filter 25, and further diluted to reduce the moisture value to about 17%. In the bag filter 25, slaked lime powder, which is a processing agent, is blown into exhaust gas at the entrance, and harmful substances (chloride, sulfide, heavy metal, etc.) agglomerated by dust and processing agent in the exhaust gas in the bag filter 25. It is removed and further discharged to the atmosphere from a chimney 27 via an attraction fan 26.

According to the above configuration, the exhaust gas before introduction into the bag filter 25 is mixed with the cooling / dilution air in the mixer 24 so that the temperature of the exhaust gas is reduced.
The temperature can be adjusted to a temperature suitable for the air conditioner, and the amount of water contained in the exhaust gas discharged into the atmosphere from the chimney 27 is further diluted to prevent white smoke. Therefore, although the capacity of the exhaust gas line 21 on the outlet side from the bag filter 25, the induction fan 26, and the mixer 24 is required to be large, a gas-type air preheater, a temperature control tower, an air compressor, Since a cooling water pump, a hot air fan, a dust recovery conveyor, a steam-type air preheater and its piping device are not required, the equipment cost can be greatly reduced.

[0014]

[Table 1] That is, as shown in Table 1, when the equipment cost index is 100 in the conventional example of FIG.
When the conventional example of FIG.
Further, even if the conventional example of FIG. In addition, since each equipment is reduced, maintenance cost and installation space can be reduced.

[0015]

As described above, according to the first aspect of the present invention, the mixing device is arranged at the inlet side of the bag filter, and the cooling and dilution air is blown into the exhaust gas, so that the temperature suitable for the bag filter is adjusted. In addition to cooling down, it is possible to prevent white smoke when the moisture value is diluted and released into the atmosphere. Therefore, although the exhaust gas capacity in the bag filter, the induction fan, and the exhaust gas passage on the downstream side is increased, compared with the conventional exhaust gas treatment equipment having a white smoke prevention function,
The equipment can be reduced, and the equipment cost can be significantly reduced even if the previously increased capacity is subtracted. Also, by reducing the number of devices, the occupied volume can be reduced, and the size can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an exhaust gas treatment facility according to the present invention.

FIG. 2 is a configuration diagram showing a conventional example A of an exhaust gas treatment facility.

FIG. 3 is a configuration diagram showing another conventional example B of the exhaust gas treatment equipment.

FIG. 4 is a configuration diagram showing another conventional example C of the exhaust gas treatment equipment.

[Explanation of symbols]

 21 Exhaust gas line 22 Incinerator 23 Heat recovery boiler 24 Mixer 25 Bag filter 26 Induction fan 27 Chimney 28 White smoke prevention fan

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K065 AA24 AB01 AC01 BA05 HA02 HA03 3K070 DA04 DA16 DA32 DA47

Claims (2)

[Claims] An exhaust gas discharged from an incinerator is introduced into a boiler to recover heat, an exhaust gas discharged from the boiler is introduced into a mixer, and the exhaust gas is cooled by blowing air which is also used for cooling and diluting, and is cooled. The exhaust gas having a white smoke prevention function characterized in that the exhaust gas discharged from the mixer is introduced into a bag filter to remove dust and harmful substances, and then the exhaust gas is attracted and discharged to the atmosphere. Processing method. 2. A boiler for introducing exhaust gas discharged from an incinerator and recovering heat, and introducing the exhaust gas discharged from the boiler to blow air for cooling and dilution to cool the exhaust gas and to remove water contained in the exhaust gas. And a bag filter for introducing exhaust gas discharged from the mixer to remove dust and harmful substances, and an induction fan for discharging exhaust gas discharged from the bag filter to the atmosphere. An exhaust gas treatment facility having a function to prevent white smoke.