JPH11179146A - Waste gas treatment system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a waste gas treatment system excellent in economy by reducing noises at a flue outlet to a value not higher than a specified value without inviting increase in equipment costs and consumption power and enabling application of inexpensive metals such as carbon steel and organic materials such as FRP as a fan material of a desulfurization fan. SOLUTION: Heat exchangers 23 for recovering heat from a waste gas, an electric dust precipitator 24 for removing dust in the waste gas cooled by the heat exchanger, a flue gas desulfurization device 26 for removing sulfur oxide contained in the waste gas by bringing the waste gas into gas-liquid contact with an absorbing solution containing an alkaline constituent and a reheating heat exchanger 28 for reheating the waste gas detoxified by the desulfurization device are arranged in this order along a flue duct 21 of the waste gas. A desulfurization fan 27 is provided for introducing the waste gas into the flue gas desulfurization device between the electric duct precipitator 24 and the flue gas desulfurization device 26.

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 system for removing sulfur oxides and particulate matter from exhaust gas discharged from a boiler or the like of a thermal power plant to make the exhaust gas harmless.

[0002]

2. Description of the Related Art As one type of an exhaust gas treatment system for detoxifying a large amount of exhaust gas generated from a boiler or the like of a thermal power plant, first, an exhaust gas discharged from a boiler or the like and passed through an air preheater is applied to an electric dust collector. The dust contained in the exhaust gas is collected, and then the exhaust gas is sent to a heat exchanger to recover the heat and then sent to a flue gas desulfurization unit where the exhaust gas and limestone (CaCO ₃ ) are dissolved or suspended. The absorbent solution made of an aqueous solution is brought into gas-liquid contact, and sulfur dioxide gas (SO ₂ ) contained in the exhaust gas is absorbed and removed in the absorbent solution to make it harmless, and the exhaust gas is reheated. 2. Description of the Related Art It is widely known that a heat exchanger is reheated to prevent white smoke by using heat recovered by the heat exchanger and then discharged to the atmosphere from a chimney.

By the way, in such an exhaust gas treatment system, the exhaust gas sent from the boiler passes through the treatment system in the flow path of the exhaust gas from the boiler to the chimney through the preheater to cover a required pressure loss. It is necessary to interpose a desulfurization fan to make it work. On the other hand, in the above-mentioned exhaust gas treatment system, a Jungstrom integrated heat exchanger has been generally used as a heat exchanger for recovering heat of the exhaust gas and a heat exchanger for reheating before releasing to the atmosphere. .
This Jungstrom heat exchanger is a so-called rotary heat exchanger, in which a rotor having a built-in heat accumulator is straddled across both flow paths of the exhaust gas on the low temperature side and the exhaust gas on the high temperature side from the boiler outlet side. The heat exchange is performed by causing the heat recovered in the high-temperature exhaust gas flow path to radiate heat in the low-temperature side exhaust gas flow path by rotating.

[0004] In the Jungstrom heat exchanger, high-temperature exhaust gas that has not been desulfurized is passed through a gap that is inevitably provided for rotating the rotor.
There is a possibility that the gas will leak to the low-temperature exhaust gas after treatment discharged from the chimney and be released to the atmosphere as it is. For this reason, by usually disposing the desulfurization fan on the outlet side of the heat exchanger for heat recovery and maintaining the exhaust gas flow path on the high temperature side at a negative pressure,
The high-temperature exhaust gas before the treatment was prevented from flowing toward the low-temperature exhaust gas after the treatment.

[0005]

However, if the desulfurization fan is disposed immediately after the heat exchanger, the exhaust gas flowing through the desulfurization fan is not included in the exhaust gas because the desulfurization treatment has not been performed yet. There is a problem that the fan is corroded by the SO _{3 that is} generated. For this reason, it is necessary to use an expensive alloy having corrosion resistance, such as Inconel or Hastelloy, as a fan material, and there has been a problem that the equipment cost is increased.

From this point of view, in recent years, as the heat exchanger, a non-leak type heat exchanger in which a heat exchanger for heat recovery and a heat exchanger for reheating are separated from each other and a circulation line of a heat medium is provided therebetween. Heat exchangers are frequently used. According to this non-leak type heat exchanger, since there is no leakage between the high-temperature side exhaust gas and the low-temperature side exhaust gas, the desulfurization fan is purposely exposed to a corrosive atmosphere for heat recovery. There is no need to install immediately after the heat exchanger. FIG. 4 shows an exhaust gas treatment system provided with a conventional non-leak type heat exchanger of this type. In this exhaust gas treatment system, an air heater is sequentially arranged along an exhaust gas duct 2 from a boiler 1. 3, electric precipitator 4, exhaust gas suction fan 5,
A gas gas heater 6 for heat recovery, a flue gas desulfurization device 7, and a gas gas heater 8 for reheating are provided. At the outlet side of the gas gas heater 8, a pressure loss generated when exhaust gas is introduced into the flue gas desulfurization device 7. A desulfurization fan 9 is provided for the purpose. The discharge side of the desulfurization fan 9 is led to a chimney 10. Reference numeral 11 in the figure denotes a circulation line for circulating and supplying the heat medium between the gas gas heaters 6 and 8. Usually, in this type of processing system, a bypass duct 12 of the processing system is provided from the exhaust gas suction fan 5 to the chimney 10.

In the conventional exhaust gas treatment system having the above-described configuration, first, the exhaust gas discharged from the boiler 1 is guided to the air heater 3 after passing through a denitration facility (not shown), and is used for preheating the combustion air of the boiler 1. After that, the dust is sent to the electrostatic precipitator 4 by the suction force of the suction fan 5, and the accompanying dust is collected and removed. Next, the exhaust gas that has exited the electrostatic precipitator 4 is once sent to a gas gas heater 6 to recover its heat, and then introduced into the flue gas desulfurization unit 7 by suction of the desulfurization fan 9. Then, in the flue gas desulfurization device 7, gas-liquid contact is made with an absorbing solution composed of an aqueous solution in which limestone is dissolved or suspended, and the sulfurous acid gas or the like contained in the exhaust gas is absorbed and removed by the absorbing solution, and the electricity is removed. The dust that has been entrained without being collected in the dust collector 4 is also collected and removed in the absorbing liquid.
The exhaust gas thus detoxified is reheated by the heat medium supplied from the circulation line 11 to prevent white smoke in the reheat gas gas heater 8, and then passes through the desulfurization fan 9. Released from the chimney 10 to the atmosphere.

In such a conventional exhaust gas treatment system, the desulfurization fan 9 is disposed downstream of the flue gas desulfurization device 7 and the gas heater 8 for reheating. In the smoke desulfurization unit 7, SO ₃ ,
Sulfurous acid gas and the like are removed to render them harmless, and the gas gas heater 8 sucks non-corrosive exhaust gas with reduced humidity.

However, in the above-mentioned conventional exhaust gas treatment system, the desulfurization fan 9 is large, such as several thousand kW, and is disposed immediately before the chimney 10. There is a problem that the generated noise is transmitted to the surroundings from the chimney 10 together with the emission of the exhaust gas without being attenuated. Therefore, in order to cope with this, it is necessary to additionally install a large-sized silencer on the discharge side of the desulfurization fan 9 and the like. As a result, in addition to adding an expensive silencer, the silencer further increases a new pressure loss source. Therefore, it is necessary to increase the size of the desulfurization fan 9 itself, which causes an increase in equipment cost and power consumption of the entire system.

The present invention has been made to effectively solve the problems of the above-mentioned conventional exhaust gas treatment system, and reduces the noise at the smoke outlet to a predetermined value or less without increasing equipment costs and power consumption. It is also possible to provide an exhaust gas treatment system which is economical and can use an inexpensive carbon steel-based metal material or an organic material such as FRP as a fan material of a desulfurization fan. It is the purpose.

[0011]

According to a first aspect of the present invention, there is provided an exhaust gas treatment system according to the present invention, comprising: a heat exchanger for sequentially recovering heat from exhaust gas along an exhaust gas exhaust duct; An electrostatic precipitator for removing particulate matter in exhaust gas having a lowered temperature, and a flue gas desulfurization device for absorbing and removing sulfur oxides contained in the exhaust gas by bringing the exhaust gas into gas-liquid contact with an absorbent containing an alkali component And a reheating heat exchanger for reheating exhaust gas detoxified by the flue gas desulfurization device, and exhaust gas is discharged between the electric dust collector and the flue gas desulfurization device. A desulfurization fan for introducing into a smoke desulfurization device is provided. The desulfurization fan is a desulfurization fan provided separately from the conventional exhaust gas suction fan, as long as the exhaust gas to be sent is supplied to the flue gas desulfurization device while covering a required pressure loss. In addition to the fan, it also includes a desulfurization fan integrated with the suction fan. here,
The invention according to claim 2 is a non-leak type heat exchanger in which the heat exchanger and the reheating heat exchanger are provided separately with a heat medium circulation line being piped between the heat exchangers. It is characterized by being.

Further, the invention described in claim 3 is the first invention.
Or the flue gas desulfurization device according to 2, wherein an absorbent containing an alkali component for neutralizing sulfur oxides and removing the sulfates as sulfates,
It is a wet flue gas desulfurization device that makes gas-liquid contact with exhaust gas, and the invention according to claim 4 is characterized in that the flue gas desulfurization device neutralizes sulfur oxides to form sulfates. It is a gas dispersion type flue gas desulfurization apparatus in which exhaust gas is dispersed in an absorbing liquid containing an alkali component to be removed and brought into gas-liquid contact. Further, in the invention according to claim 5, the flue gas desulfurization device injects exhaust gas into the absorbent through a number of sparger pipes, and the oxidizing means is introduced into the absorbent. It is characterized by a flue gas desulfurization system of a jet bubbling type.

The dust removal performance of the electric precipitator disposed upstream of the flue gas desulfurization device depends on the electric resistance of the dust, and the electric resistance of the dust depends on the relative humidity of the exhaust gas. When the exhaust gas temperature at the entrance of the electrostatic precipitator is reduced, the dust removing performance of the electric precipitator can be improved. In the exhaust gas treatment system according to any one of claims 1 to 5, a heat exchanger for recovering heat from the exhaust gas is disposed upstream of the electric dust collector. The dust is collected and removed from the exhaust gas with high efficiency in the dust container. At this time, SO ₃ in the exhaust gas is also removed from the exhaust gas together with the particulate matter while adsorbed on the particulate matter.

Therefore, even if a desulfurization fan is provided on the outlet side of the electric dust collector, there is no fear that the desulfurization fan is subject to corrosion or wear unlike the conventional one. As a result, an inexpensive carbon steel-based metal material can be used as a material for the fan, and an organic material such as FRP can be used because of low dust and low temperature. Also, as described above, the exhaust gas discharged from the desulfurization fan is accompanied by noise, but when the exhaust gas desulfurization device at the subsequent stage comes into gas-liquid contact with the absorbent containing an alkali component, an acoustic damping effect is simultaneously obtained. As a result, the noise generated in the desulfurization fan is greatly attenuated. As a result, the noise of the exhaust gas discharged from the chimney can be reduced to a predetermined value or less without separately providing a noise attenuation device such as a silencer on the outlet side of the desulfurization fan.

Here, the above-mentioned flue gas desulfurization device is defined in claim 3.
As described above, there is provided a wet flue gas desulfurization apparatus in which an absorbent containing an alkali component for neutralizing a sulfur oxide and removing it as a sulfate is brought into gas-liquid contact with an exhaust gas. The present invention relates to various wet flue gas desulfurization devices, such as a spray type in which an absorbent is dispersed in exhaust gas and gas-liquid contact, and a gas dispersion type in which exhaust gas is dispersed in gas and liquid contact. However, in a gas dispersion type flue gas desulfurization apparatus, a greater noise reduction effect, that is, a noise attenuation effect can be obtained as compared with a spray type desulfurization apparatus. Therefore, when the present invention is applied to a gas dispersion type flue gas desulfurization apparatus as in the invention described in claim 4, more remarkable effects can be obtained.

In particular, when a jet bubbling type flue gas desulfurization device is used as the gas dispersion type flue gas desulfurization device, a large number of exhaust gas with noise is generated. When dispersed in a jar pipe,
The first-stage noise attenuating effect is obtained, and the second-stage sound-absorbing effect is obtained in the liquid-phase continuous jet bubbling layer, so that the noise accompanying the exhaust gas is largely attenuated. Is the most suitable.

[0017]

FIG. 1 and FIG. 2 show an embodiment of an exhaust gas treatment system according to the present invention.
As shown in FIG. 1, in the exhaust gas treatment system, an air heater 22, a gas gas heater (heat exchanger) 23 for heat recovery, an electric dust collector 24 are sequentially arranged along an exhaust gas duct 21 extending from a boiler 20. , An exhaust gas suction fan 25, a desulfurization fan 27, and a flue gas desulfurization device 26 are provided. Here, the desulfurization fan 27 includes a fan made of a carbon steel-based metal material or an organic material such as FRP. And, on the downstream side of the flue gas desulfurization device 26,
A gas gas heater (heat exchanger) 28 for reheating is provided, and an exhaust gas duct 21 from the gas gas heater 28 is led to a chimney 29. And gas gas heater 2
A circulation line 30 for circulating and supplying the heat medium is provided between 3 and 28. Also, the exhaust gas suction fan 25
, A bypass line 12 of the processing system is provided.

As shown in FIG. 2, the flue gas desulfurization unit 26 has a circular or square horizontal cross section. An upper deck 31 and a lower deck 32 are vertically spaced from each other in an upper space. It is arranged. These upper and lower decks 31,
Numeral 32 is provided as a partition for airtightly defining an internal space. A lower space of the lower deck 32 is a storage tank 34, and a space between the upper deck 31 and the lower deck 32 is an inlet plenum 3.
5. The upper space of the upper deck 31 is an outlet plenum 36. In the storage tank 34, an absorbent K made of limestone slurry is stored at a predetermined level. The inlet plenum 35 has an inlet duct 37 for introducing exhaust gas.
The outlet plenum 36 is connected to an outlet duct 38 that guides the treated exhaust gas to the outside.
The cooling pipe 33 is introduced into the inlet duct, and the mist eliminator 39 is provided in the outlet duct 38.

On the other hand, the lower deck 32 is provided with a large number of openings in a distributed manner, and each opening is connected to an upper end of a sparger pipe 40 suspended from the lower surface of the lower deck 32. . The lower end of the sparger pipe 40 is suspended in the absorbent K in the storage tank 34, and exhaust gas discharge holes 40a are formed in the outer periphery of each lower end in the horizontal direction. The exhaust gas discharge hole 40a is opened at a predetermined depth below the liquid surface of the absorbing liquid K, and discharges exhaust gas horizontally below the liquid surface of the absorbing liquid K.

A gas riser 41 is provided between the lower deck 32 and the upper deck 31 so as to communicate the upper space above the absorbent surface of the storage tank 34 with the outlet plenum 36 so as to pass through the inlet plenum 35. ing. Further, at the bottom of the storage tank 34, a supply pipe 42 for oxidizing air for ejecting oxidizing air and a stirrer 43 for stirring the absorbing liquid K are provided. It is connected to a blower 44 for pumping working air. A slurry pump 45 is connected to the storage tank 34. The flue gas desulfurization device 26 has a supply pipe 4 for replenishing the limestone slurry (neutralizing agent slurry) into the storage tank 34.
6 are connected. The proximal end of the supply pipe 46 is connected to a pump (not shown) that is a limestone slurry pressure source. Further, the mother liquor from which the gypsum (sulfate) generated from the absorbing liquid K extracted by the slurry pump 45 is removed is again stored in the storage tank 3.
4 and a circulation supply line for circulating the absorption liquid K are provided.

In the present invention, various types other than the above-mentioned flue gas desulfurization device 26 can be applied. For example, FIG. 3 shows a jet bubbling system similar to that shown in FIG.
6 ′. In this flue gas desulfurization device 26 ', a lower space is defined by a deck 32' into a storage tank 34 and an inlet plenum 35, and an absorption liquid K made of limestone slurry is provided inside the storage tank 34. Are stored at a predetermined level. An inlet duct 37 for introducing exhaust gas is connected to the inlet plenum 35, while the storage tank 34 is connected to the inlet plenum 35.
An outlet duct 38 for leading the treated exhaust gas to the outside is connected to the upper space above the absorbing liquid surface. The cooling pipe 33 is introduced into the inlet duct, and the mist eliminator 39 is provided in the outlet duct 38.

A sparger pipe 40 is suspended from the deck 32 '.
Is suspended in the absorbing liquid K in the storage tank 34. As a result, the exhaust gas introduced into the sparger pipe 40 from the inlet plenum 35 is ejected horizontally from the exhaust gas ejection hole 40a below the level of the absorbing liquid K, and comes into gas-liquid contact with the absorbing liquid K. Is discharged to an outlet duct 38 through a mist eliminator 39.

Next, the operation of the exhaust gas treatment system having the above configuration will be described. First, the exhaust gas discharged from the boiler 20 is guided to an air heater 22 from an exhaust gas duct 21 after passing through a denitration facility (not shown), and is used for preheating combustion air of the boiler 20, and then heat is generated by a gas gas heater 23. It is collected, cooled down to about 95 ° C., and sent to the electrostatic precipitator 24. Then, in the electric precipitator 24, the entrained dust is efficiently collected and removed, and SO _{3 in} the exhaust gas is also removed from the exhaust gas together with the above-mentioned dust while being adsorbed on the dust. . In this way, the exhaust gas having a reduced SO ₃ concentration together with the particulate matter is sent to the flue gas desulfurization devices 26 and 26 ′ after being pressurized by the desulfurization fan 27.

At this time, the exhaust gas is sent into the flue gas desulfurization devices 26 and 26 'together with the noise generated in the desulfurization fan 27. Then, the flue gas desulfurization devices 26 and 26 '
When the exhaust gas is cooled by spraying from the cooling pipe 33 of the inlet duct 37 and then fed to the inlet plenum 35 while supplying oxygen into the absorbing liquid K through the supply pipe 42, the exhaust gas is supplied to each sparger pipe 40. Through the ejection hole 40a at the lower end, and vigorously mixed with the absorbing liquid K to form a liquid phase continuous jet bubbling layer. At this time, the agitator 43 is rotated to agitate the absorbing liquid K, and the oxidizing air supplied from the supply pipe 42 is continuously supplied into the absorbing liquid K from the nozzle at the tip. This allows
In the jet bubbling layer, highly efficient gas-liquid contact is performed, and SO ₂ + CaCO ₃ +1/2 O ₂ + 2H ₂ O → CaSO ₄
・ As shown by 2H ₂ O ↓ + CO ₂硫酸, sulfurous acid gas (S
O ₂ ) is oxidized and a reaction neutralized by the limestone in the absorbing solution K is performed, whereby the sulfur dioxide gas is absorbed and removed.

At the same time, when the exhaust gas accompanied by noise is first dispersed into a large number of sparger pipes 40, the noise is attenuated and the exhaust gas comes into contact with the liquid-phase continuous jet bubbling layer. The accompanying noise in the absorbing liquid is reduced. In this way, in the flue gas desulfurization devices 26 and 26 ′, the particulate matter entrained in the exhaust gas is collected and removed with high efficiency in the absorbent K, and the noise entrained from the desulfurization fan 27 is reduced. Reduced. The exhaust gas that has been desulfurized, dedusted, made harmless and acoustically reduced in temperature has a temperature of 40 to 50 ° C., and the gas riser 4 shown in FIG.
1 through an outlet plenum 36 to an outlet duct 38, and in the embodiment shown in FIG. 3, the mist is directly guided from the space above the level of the absorbent K to the outlet duct 38, After the components are removed, the gas is reheated to 90 to 100 ° C. by a heat medium supplied from the circulation line 30 to prevent white smoke in the reheating gas gas heater 28, and then discharged to the atmosphere from the chimney 29. You.

On the other hand, gypsum (CaSO ₄₎ generated in the absorbing solution by oxidizing and neutralizing sulfur dioxide gas (SO ₂ )
2H ₂ O) · becomes a absorbing liquid gypsum slurry by coarse particles by being grown, upon reaching a predetermined concentration, it is withdrawn from the reservoir 34 by the slurry pump 45, to the mother liquor and plaster Separated. The mother liquor is mixed with fresh liquor and supplied into the storage tank 34 through the supply line 46 as a replenishing absorbent.

As described above, according to the exhaust gas treatment system having the above configuration, the heat exchanger 23 for recovering heat from the exhaust gas is disposed upstream of the electric precipitator 24.
By reducing the temperature of the exhaust gas, the dust can be collected and removed from the exhaust gas with high efficiency in the electric precipitator 24. At this time, SO ₃ in the exhaust gas can also be removed from the exhaust gas together with the dust while being adsorbed by the dust. Therefore, even if the desulfurization fan 27 is disposed on the outlet side of the electrostatic precipitator 24, there is no possibility that the desulfurization fan 27 will be corroded or worn, and as a material of the fan, an inexpensive carbon steel metal material or FRP is used. And other organic materials can be used.

Although the exhaust gas discharged from the desulfurization fan 27 is accompanied by noise, the flue gas desulfurization devices 26 and 26 'at the subsequent stage are used.
At the same time, gas-liquid contact with the absorbing liquid can simultaneously obtain an acoustic damping effect, which allows the desulfurization fan 2
7, the noise generated can be greatly attenuated. As a result, the noise of the exhaust gas emitted from the chimney 29 can be reduced to a predetermined value or less without separately providing a noise attenuation device such as a silencer on the outlet side of the desulfurization fan 27. In particular, since the flue gas desulfurization devices 26 and 26 ′ are of the jet bubbling type, when the exhaust gas with noise is first dispersed into a large number of sparger pipes 40, a noise attenuation effect is obtained. Even in the jet bubbling layer having a continuous liquid phase, an effective noise reduction effect can be obtained, so that the noise accompanying the exhaust gas can be greatly attenuated.

As described above, the present invention is applicable to various types of wet flue gas desulfurization devices in addition to the jet bubbling type flue gas desulfurization devices 26 and 26 'shown in FIGS. . Further, in the above-described embodiment, only the case where the exhaust gas suction fan 25 and the desulfurization fan 27 are separate has been described. However, the present invention is not limited to this, and the suction fan and the desulfurization fan are integrated. Can also be used. In this case, an integrated desulfurization fan may be provided between the electric dust collector and the flue gas desulfurization device.

[0030]

As described above, according to any one of the first to fifth aspects of the present invention, on the upstream side of the electric precipitator,
Since a heat exchanger that recovers heat from exhaust gas is installed,
In the electrostatic precipitator can be removed by collecting the medium dust at high efficiency from the exhaust gas, SO ₃ simultaneously in the exhaust gas
Also, since it can be removed from the exhaust gas together with the dust while being adsorbed by the dust, even if a desulfurization fan is arranged at the outlet side of the electric dust collector, the desulfurization fan may be corroded. Therefore, an inexpensive carbon steel-based metal material or an organic material such as FRP can be used as a material for the fan. And the exhaust gas discharged from the desulfurization fan is
At the time of gas-liquid contact with an absorbent containing an alkali component in a flue gas desulfurization device at the subsequent stage, a noise reduction effect is obtained at the same time, and the noise generated in the desulfurization fan is greatly attenuated. The noise of the exhaust gas emitted from the chimney can be reduced to a predetermined value or less without separately providing a noise attenuation device such as a silencer on the side.

In particular, when the flue gas desulfurization device is a gas dispersion type flue gas desulfurization device, a more remarkable acoustic damping effect can be obtained, As in the invention according to claim 5, in the case of using a flue gas desulfurization apparatus of a jet bubbling method, when exhaust gas with noise is dispersed to a number of sparger pipes,
The first-stage noise attenuating effect is obtained, and the second-stage sound-absorbing effect is obtained in the above-described liquid-phase continuous jet bubbling layer, so that the noise accompanying the exhaust gas is further greatly attenuated. The effect of being able to do is obtained.

[Brief description of the drawings]

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

FIG. 2 is a configuration view of the flue gas desulfurization device of FIG.

FIG. 3 is a cross-sectional view showing another example of the flue gas desulfurization device of FIG. 1;

FIG. 4 is a schematic configuration diagram showing a conventional exhaust gas treatment system.

[Explanation of symbols]

 Reference Signs List 20 boiler 23 gas gas heater (heat exchanger) 24 electric dust collector 26, 26 'flue gas desulfurization device 27 desulfurization fan 28 gas gas heater for reheating (heat exchanger for reheating) 40 sparger pipe 42 supply of air for oxidation Pipe (oxidizing means) K Absorbing liquid

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Atsushi Watanabe 2-1-1, Tsurumichuo, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Chiyoda Kako Construction Co., Ltd. (72) Inventor Hiroshi Goga Tsurumi-chuo, Tsurumi-ku, Yokohama-shi, Kanagawa 2-12-1 Chiyoda Kako Construction Co., Ltd.

Claims (5)

[Claims] 1. A heat exchanger for sequentially recovering heat from an exhaust gas along an exhaust gas exhaust duct, an electric precipitator for removing particulate matter in the exhaust gas cooled by the heat exchanger, A flue gas desulfurization device that absorbs and removes sulfur oxides contained in the exhaust gas by bringing the component into gas-liquid contact with an absorbing solution containing components, and a reheating process that reheats the exhaust gas that has been detoxified by the flue gas desulfurization device. A heat exchanger is provided, and between the electric precipitator and the flue gas desulfurization device,
An exhaust gas treatment system comprising a desulfurization fan for introducing exhaust gas into the flue gas desulfurization device. 2. The heat exchanger and the reheating heat exchanger are non-leak type heat exchangers in which a heat medium circulation line is provided between the heat exchangers and separately disposed. The exhaust gas treatment system according to claim 1, wherein: 3. The flue gas desulfurization device, wherein the flue gas desulfurization device is a gas-liquid flue gas desulfurization device for bringing an absorbent containing an alkali component for neutralizing the sulfur oxides and removing it as a sulfate into gas-liquid contact with the exhaust gas. The exhaust gas treatment system according to claim 1 or 2, wherein: 4. The exhaust gas desulfurization apparatus according to claim 1, wherein the exhaust gas is dispersed in an absorbing solution containing an alkali component for neutralizing the sulfur oxide and removing the sulfur oxide as a sulfate, and the gas is subjected to gas-liquid contact. 4. The device according to claim 3, wherein the device is a smoke desulfurization device.
An exhaust gas treatment system according to item 1. 5. The exhaust gas desulfurization device injects the exhaust gas into the absorbent through a number of sparger pipes and uses a jet bubbling type exhaust gas in which the oxidizing means is introduced into the absorbent. The exhaust gas treatment system according to claim 4, which is a smoke desulfurization device.