JP6462416B2 - SO3 removal apparatus, exhaust gas treatment system, and SO3 removal method - Google Patents

Description

The present invention relates to an SO ₃ removal device that removes SO ₃ contained in exhaust gas, and an SO ₃ removal method using the same. The present invention also relates to an exhaust gas treatment system including the SO ₃ removal device.

Dust (particulate matter) and exhaust gas containing SOx gas such as SO ₂ and SO ₃ are discharged from industrial combustion facilities such as coal-fired and heavy oil-fired power plants. Gases containing dust and SOx are also discharged from marine engines using light oil and heavy oil as fuel.

  An exhaust gas treatment system is provided in a flue downstream of a combustion facility such as a boiler or an engine. In the exhaust gas treatment system, as in Patent Document 1, for example, a denitration device, an air heater, a dust collector, a wet desulfurization device, and a wet electric dust collector are installed in order from the upstream side.

In the wet desulfurization apparatus, for example, a slurry containing limestone (an alkali agent such as CaCO ₃ ) is sprayed in an absorption tower, and the slurry and the exhaust gas are brought into gas-liquid contact to react SO ₂ in the exhaust gas with CaCO _3. Remove from exhaust gas.

In the wet desulfurization apparatus, since the reaction is performed in a water saturated state, it is necessary to cool to near the water dew point. For this reason, exhaust gas temperature falls rapidly by spraying water from a cooling device or spraying a lot of slurry. When the exhaust gas temperature falls below the acid dew point (sulfuric acid dew point) temperature, the SO ₃ gas in the exhaust gas becomes a mist state. Therefore, SO ₃ mist flows in the absorption tower, and the SO ₃ mist and the dispersed slurry are collected only by collision. However, since the contact probability is low, the SO ₃ removal efficiency in the wet desalting apparatus is poor. The SO ₃ mist remaining in the exhaust gas causes metal corrosion and purple smoke in the latter stage of the wet desulfurization apparatus. For this reason, the exhaust gas treatment system is required to improve SO ₃ removal efficiency.

For example, in the technique described in Patent Document 2, the concentration of SO ₃ in exhaust gas is reduced by charging and collecting SO ₃ mist in a wet electrostatic precipitator.

Patent Literature 3 generates solid ammonium sulfate ((NH ₄ ) ₂ SO ₄ ) by injecting ammonia into a flue between an air heater and a dust collector, and reacting ammonia with SO ₃ . Disclosed is technology for collecting ammonium sulfate with an electrostatic precipitator.

JP 2010-69463 A JP2013-123692A Japanese Patent No. 3860977

When the SO ₃ concentration in the exhaust gas is low, the SO ₃ mist that reaches the wet electrostatic precipitator becomes low (for example, 10 ppm or less), so that the SO ₃ mist can be sufficiently removed by the wet electrostatic precipitator. However, when fuel with a high sulfur content is burned, the concentration of SO ₃ in the exhaust gas becomes high, and a high concentration of SO ₃ mist reaches the wet electrostatic precipitator. Since a very large apparatus is required to sufficiently remove high-concentration SO ₃ with a wet electrostatic precipitator, it is not economical.

In the method of Patent Document 3, the ammonia amount increases as the SO ₃ concentration increases. Moreover, it was necessary to process the ammonium sulfate collected by the electrostatic precipitator. For this reason, the method of Patent Document 3 has a problem that the processing cost is high.

The present invention has been made in view of the above problems, and provides an SO ₃ treatment device and an SO ₃ treatment method capable of easily and efficiently removing SO ₃ from exhaust gas, and an exhaust gas treatment system including the SO ₃ treatment device. The purpose is to do.

A first aspect of the present invention is an SO ₃ removal device provided in a flow passage through which an exhaust gas containing SO _{3 in} a gaseous state flows, wherein the exhaust gas is cooled to a sulfuric acid dew point temperature or lower, and the exhaust gas is cooled to a collecting member for collecting the mist with to generate mist containing SO _3, based on the temperature of the collecting member, SO ₃ and a cooling unit for maintaining said collecting member below the sulfuric acid dew point It is a removal device.

A second aspect of the present invention, exhaust gas containing SO ₃ in the gaseous state is provided in the flow passage flows, a collecting member, the SO ₃ from the flue gas with SO ₃ removing apparatus and a cooling section In this method, the collection member cooled to a sulfuric acid dew point temperature or less contacts the exhaust gas containing SO ₃ in a gaseous state, and the exhaust gas is cooled to the sulfuric acid dew point temperature or less to remove the SO ₃ . A step in which the mist is generated, a step in which the mist is collected on the surface of the collecting member, and the cooling unit lowers the collecting member to the sulfuric acid dew point temperature or less based on the temperature of the collecting member. And a step of maintaining the SO ₃ removal method.

The SO ₃ removing apparatus and SO ₃ removal method of the present invention, leaving the SO ₃ and gaseous state before contacting the collecting member. Cooling the SO ₃ gas by contacting the collecting member and the SO ₃ gas is cooled below sulfate dew point, is converted to mist (SO ₃ mists) containing SO ₃ in the vicinity of the collecting member. The generated SO ₃ is attached to the surface of the collecting member. By so doing, SO ₃ can be easily and efficiently removed from the exhaust gas.

By contacting the exhaust gas containing SO ₃ , the temperature of the surface of the collecting member increases. In the present invention, the collecting member is maintained below the sulfuric acid dew point temperature based on the temperature of the collecting member. If the process of cooling the collection member is shortened, the time of the process of cooling the exhaust gas and the process of collecting the mist becomes longer. Therefore, according to the SO ₃ removal apparatus and the SO ₃ removal method of the present invention, it is possible to maintain high SO ₃ removal efficiency over a long period of time.

In the first aspect and the second aspect, the collection member may be a sensible heat storage material made of ceramics. Or the latent heat storage material in which the said collection member has melting | fusing point below the said sulfuric acid dew point temperature may be sufficient.
By using the heat storage material as a collecting member, the temperature below the sulfuric acid dew point can be maintained for a long period of time, and corrosion deterioration under an acidic atmosphere can be prevented.

In the first and second aspects, the collecting member may be a heat transfer body having acid resistance.
If the collection member is a heat transfer body, the entire collection member can be easily and quickly cooled. Therefore, the SO ₃ removal apparatus of the present invention can continue the SO ₃ removal process while the cooling unit maintains the collection member below the sulfuric acid dew point temperature even when the high temperature exhaust gas contacts the collection member. Furthermore, since the heat transfer body has acid resistance, it is possible to prevent corrosion deterioration due to long-term use in an acidic atmosphere.

  1st aspect WHEREIN: It is preferable that the said cooling part supplies the cooling liquid to the surface of the said collection member of the side which contacts the said waste gas, and the said cooling liquid cools the said surface directly. In this case, it is preferable that the mist in which the cooling liquid is collected by the collecting member is removed from the collecting member.

  2nd aspect WHEREIN: It is preferable to supply a cooling liquid to the surface of the said collection member of the side in which the said cooling part contacts the said waste gas, and to cool the said surface directly with the said cooling liquid. In this case, it is preferable that the mist in which the cooling liquid is collected by the collecting member is removed from the collecting member.

Cooling efficiency can be improved by directly cooling the surface of the collecting member that contacts the exhaust gas.
Furthermore, the SO ₃ mist collected by the collecting member can be removed from the collecting member as the coolant flows. This is advantageous because the collecting member can be cooled and cleaned at the same time. Since the surface of the collecting member is in a clean state after the process of cooling the collecting member is completed, high collecting performance can be maintained without clogging the collecting member, and stable operation is possible. Will continue.

In the first aspect, when the collection member is a heat transfer body, the cooling unit supplies a coolant to the heat transfer body, and the surface of the heat transfer body on the side where the coolant comes into contact with the exhaust gas is indirectly May be cooled. In this case, the SO ₃ removal device includes a cleaning unit that supplies a cleaning liquid to the collection member.

  In the second aspect, when the collection member is a heat transfer body, the cooling unit supplies the cooling liquid to the heat transfer body, and indirectly cools the surface of the heat transfer body with the cooling liquid. Also good. In this case, a cleaning liquid is supplied to the collecting member, and the mist collected by the collecting member is removed from the collecting member.

If the collection member is a heat transfer body, it becomes easy to maintain the temperature of the collection member at or below the sulfuric acid dew point temperature by indirectly cooling the surface in contact with the exhaust gas.
When performing indirect cooling, high removal efficiency can be maintained by supplying cleaning liquid to the collection member and periodically removing SO ₃ mist adhering to the collection member.

  In the first aspect, the collection member may have a plurality of through holes, and the exhaust gas may be circulated in the through holes to collect the mist on the inner walls of the through holes.

  2nd aspect WHEREIN: The said collection member has a some through-hole, and when the said waste gas distribute | circulates each of the said through-hole, the said waste gas is cooled and the said mist produces | generates, and it is on the inner wall of the said through-hole The mist may be collected.

  In this case, the cooling unit supplies cooling liquid to at least one of the through holes to cool the surface of the through hole, and the exhaust gas flows through the remaining through holes simultaneously with the cooling of the at least one through hole. When the cooling of the at least one through hole is completed, it is preferable that the exhaust gas flows through the at least one through hole.

By forming a through hole in the collecting member, the contact area with the gas can be increased. An increase in the contact area leads to an improvement in SO ₃ removal efficiency.
While cooling liquid is supplied to the through hole to cool the collecting member, the exhaust gas is blocked in the through hole. As in the above configuration, exhaust gas cooling and SO ₃ mist collection are continued in the remaining through-holes that are not cooled. Thereby, it is possible to perform continuous SO ₃ removal processing in one of the collecting member.

1st aspect WHEREIN: It is comprised by the accommodating part which has several opening, and the said granular collection member with which the said accommodating part is filled, and is arranged in the direction substantially orthogonal to the distribution direction of the said exhaust gas in the said flow path. that a plurality of SO ₃ has a collecting unit, the SO ₃ collecting section, and an exhaust gas space where the exhaust gas located on an upstream side of the exhaust gas of the SO ₃ collector flows, the SO ₃ collector And the processing gas space into which the processing gas from which the mist has been removed by the SO ₃ collection unit is located downstream of the exhaust gas, and a plurality of the cooling units are provided for each of the SO ₃ collection units. It may be installed corresponding to.

In a second aspect, the SO ₃ removing apparatus, and a housing portion having a plurality of openings, is configured by said collecting member particulate filled in the accommodating portion, the flow direction of the flue gas in said flow passage a plurality of SO ₃ collecting portion which is arranged in a direction substantially orthogonal, the SO ₃ collecting section, and an exhaust gas space where the exhaust gas located on an upstream side of the exhaust gas of the SO ₃ collector flows The SO ₃ collection unit is located on the downstream side of the exhaust gas and isolates the processing gas space into which the processing gas from which the mist has been removed in the SO ₃ collection unit flows, and the exhaust gas is separated from the exhaust gas space. The exhaust gas is cooled by flowing into the SO ₃ collection part and flowing between the collection members, the mist is collected on the surface of the collection member, and the processing gas is supplied to the SO ₃ collection part. Even if it is discharged from the process gas space There.

In this case, the cooling unit in response to each of a plurality of the SO ₃ collecting portion is more established, the collecting member wherein the cooling unit supplies cooling liquid to at least one of said SO ₃ collector cooled, the same time at least one cooling of the SO ₃ collecting portion, the remainder of the SO ₃ collector flows said gas and said at least one SO ₃ collecting portion cooling is completed, said at least It is preferable that the exhaust gas flows through two SO ₃ collecting portions.

Thus, by using a granular collection member, a contact area with exhaust gas can be increased. Further, since the exhaust gas flows through the gap between the collection members, the contact frequency between the exhaust gas and the collection member is increased, and exhaust gas cooling (SO ₃ mist generation) and SO ₃ mist collection are efficiently performed. be able to.
Also in the above-described configuration, there are a step in which the flow of the exhaust gas is stopped in the plurality of SO ₃ collection units and the collection member is cooled, and a step in which the exhaust gas is cooled and the SO ₃ mist is collected. Since it is performed at the same time, the SO ₃ removal process can be performed continuously.

  In the first aspect and the second aspect, when the collection member is a heat transfer body, the collection member is a member having a mesh-shaped opening, and the collection is performed when the exhaust gas passes through the opening. A member may cool the exhaust gas, and the collecting member may collect the mist.

By being a collection member having a mesh-shaped opening, the contact area with the gas can be increased, and SO ₃ removal efficiency can be increased.

  In the first aspect, the exhaust gas contains dust, a discharge electrode is disposed on the upstream side of the exhaust gas of the collection member, and an opening through which the exhaust gas can flow is upstream of the exhaust gas of the collection member. Preferably, the dust collecting electrode is disposed, the discharge electrode generates corona discharge to charge the dust, and the dust collecting electrode collects the charged dust.

  In the second aspect, the exhaust gas contains dust, a discharge electrode is disposed on the upstream side of the exhaust gas of the collection member, and an opening through which the exhaust gas can flow is upstream of the exhaust gas of the collection member. A dust collecting electrode is disposed, and the discharge electrode generates a corona discharge in a space upstream of the exhaust gas of the collecting member, and the dust is charged; and the charged dust is the dust collecting It is preferable to further include a step of collecting on the surface of the electrode.

  In the first aspect, the exhaust gas includes dust, an upstream member facing at least the exhaust gas upstream side of the housing portion is a conductive material, a discharge electrode is disposed in the exhaust gas space, and the discharge electrode is a corona. It is preferable that the dust is charged by generating a discharge, and the dust charged by the upstream member is collected.

In a second aspect, the exhaust gas contains a dust, the disposed discharge electrodes in the exhaust gas space of the SO ₃ removing apparatus, the upstream-side member at least facing the exhaust-gas upstream side of the receiving portion be conductive material Preferably, the method further includes a step of generating corona discharge in the exhaust gas space by the discharge electrode and charging the dust, and a step of collecting the charged dust on the surface of the upstream member.

  In the first aspect, when the collection member is a heat transfer body having a mesh-shaped opening, the exhaust gas includes dust, the collection member is made of a conductive material, and the upstream side of the exhaust gas of the collection member It is preferable that a discharge electrode is disposed, the discharge electrode generates a corona discharge to charge the dust, and the collecting member collects the charged dust.

  In the second aspect, when the collection member is a heat transfer body having a mesh-shaped opening, the exhaust gas contains dust, the collection member is made of a conductive material, and the upstream side of the exhaust gas of the collection member A discharge electrode is disposed in the discharge electrode, and a corona discharge is generated in a space upstream of the exhaust gas of the collection member by the discharge electrode, and the dust is charged; and the charged dust is the collection member It is preferable that the method further includes a step of collecting on the surface.

Generally, exhaust gas contains dust. In the SO ₃ removal apparatus and the SO ₃ removal method of the present invention, dust can be simultaneously removed from the exhaust gas by adhering dust to the collection member. Further, with the above configuration, dust can be more efficiently removed from the exhaust gas. As a result, the dust removal rate in the entire exhaust gas treatment system is increased, which is advantageous.

A third aspect of the present invention is an exhaust gas treatment system including the SO ₃ removal device of the first aspect and a wet desulfurization device provided on the downstream side of the exhaust gas of the SO ₃ removal device.

If the SO ₃ removal device of the first aspect is installed on the upstream side of the wet desulfurization device, the gas can be brought into contact with the collecting member at a temperature higher than the sulfuric acid dew point temperature, so that efficient SO ₃ removal is performed. be able to. As a result, since the SO ₃ concentration finally discharged from the exhaust gas treatment system is reduced, the generation of purple smoke can be prevented. In addition, it is possible to suppress acid corrosion in a device or a flue installed on the downstream side of the SO ₃ removal device.

The collecting member, which is cooled below sulfate dew point, since with to produce SO ₃ mist cooling the SO ₃ gas in the vicinity of the surface of the collecting member can be collected SO ₃ mist, high over a long period of time It is possible to easily remove SO ₃ from the exhaust gas with efficiency.

It is a block diagram of an example of an exhaust gas treatment system. It is a schematic diagram of a SO ₃ removing apparatus according to the first embodiment. It is the schematic of the heat storage material used for 1st Embodiment. It is a schematic diagram for explaining a modification of the SO ₃ removing apparatus according to the first embodiment. It is an example of a graph representing the relationship between the SO ₃ concentration and the acid dew point in the exhaust gas. It is an example of the result of having simulated the temperature change of the thermal storage material. It is a side view of the SO ₃ removing apparatus according to the second embodiment. It is AA arrow sectional drawing in FIG. It is BB arrow sectional drawing in FIG. A modification of the SO ₃ removing apparatus of the second embodiment, a B-B cross-sectional view taken along FIG. It is a side view of the SO ₃ removing apparatus according to the third embodiment. It is CC sectional view taken on the line in FIG. It is a side view of the SO ₃ removing apparatus according to the fourth embodiment. It is DD sectional view taken on the line in FIG. It is a side view of the SO ₃ removing apparatus according to a sixth embodiment. It is a side view of the SO ₃ removing apparatus according to the seventh embodiment. It is a side view of the SO ₃ removing apparatus according to the eighth embodiment. It is a side view of the SO ₃ removing apparatus according to a ninth embodiment. It is a side view of the SO ₃ removing apparatus according to a modification of the ninth embodiment. It is a side view of the SO ₃ removing apparatus according to the tenth embodiment. It is a side view of the SO ₃ removing apparatus according to an eleventh embodiment. It is a side view of the SO ₃ removing apparatus according to the twelfth embodiment. It is a side view of the SO ₃ removing apparatus according to a modification of the twelfth embodiment. It is a side view of the SO ₃ removing apparatus according to the thirteenth embodiment.

FIG. 1 is a block diagram of an example of an exhaust gas treatment system. The exhaust gas treatment system 1 is provided in a flue downstream of the combustion facility 2. The combustion facility 2 is a facility for burning fuel containing sulfur such as heavy oil or coal.
In the case of an oil-fired combustion facility (such as an industrial heavy oil-fired boiler or diesel engine) that uses heavy oil as fuel, the exhaust gas treatment system 1 includes an SO ₃ removal device 100, a wet desulfurization device 3, and a chimney 4. .

The wet desulfurization apparatus 3 sprays a slurry containing an absorbent into the exhaust gas, reacts the absorbent with SOx in the exhaust gas, and mainly removes SO ₂ from the exhaust gas.
The wet desulfurization apparatus 3 adopts a gypsum lime method, a sodium method, and a water mug method. The absorbent is CaCO ₃ (limestone) for the gypsum lime method, NaOH for the sodium method, and Mg (OH) ₂ for the water mug method. A plurality of wet desulfurization apparatuses 3 may be installed in series with the exhaust gas flow passage.

SO ₃ removing apparatus 100, before the exhaust gas flows into the wet desulfurization system 3 is for removing SO ₃ from the exhaust gas.

In the case of an industrial heavy oil fired boiler, the air heater 5 is installed on the gas upstream side of the SO ₃ removing device 100. The air heater 5 exchanges heat between the exhaust gas and the combustion air. Thus, the combustion air is heated by the sensible heat of the exhaust gas and supplied to the combustion facility 2.

In the case of a coal fired boiler, the exhaust gas treatment system 1 further includes a denitration device and a dry electrostatic precipitator on the gas upstream side of the SO ₃ removal device 100. The denitration device removes nitrogen oxides (NOx) contained in the exhaust gas flowing from the combustion facility (coal-fired boiler) 2. A dry electrostatic precipitator collects dust in exhaust gas by electrostatic force.

In the case of a coal-fired boiler, the exhaust gas treatment system 1 further includes a wet electric dust collector on the gas downstream side of the wet desulfurization device 3. The wet type electrostatic precipitator removes dust and SO ₃ mist that could not be collected by the dry type electrostatic precipitator and the wet desulfurization apparatus by electrostatic force.

  In the case of an industrial heavy oil fired boiler, a dry electrostatic precipitator and a wet electrostatic precipitator may be installed in the exhaust gas treatment system.

<First Embodiment>
FIG. 2 is a schematic diagram of the SO ₃ removal apparatus according to the first embodiment. The SO ₃ removal device 100 is installed in a flue (flow passage) 10 immediately before the wet desulfurization device 3.
In FIG. 2, the flue 10 where the SO ₃ removal device is installed is installed substantially vertically at the inlet of the wet desulfurization device 3, and the exhaust gas flows through the flue 10 from top to bottom. In the present embodiment, the exhaust gas may circulate through the flue 10 from the bottom to the top.
In addition, the SO ₃ removal device of the present embodiment can be installed in the flue where the exhaust gas circulates in a substantially horizontal direction as long as the effect of the present invention is achieved.

The SO ₃ removal device 100 includes a collection member 110 installed in the flue 10 and a cooling unit 120.

  A sensible heat storage material that uses the specific heat of the substance is used for the collection member 110 of the first embodiment. The heat storage material applicable to the present embodiment is required to have heat resistance and acid resistance. Specifically, the sensible heat storage material is a ceramic such as cordierite or alumina.

  FIG. 3 is a schematic view of the collecting member 110 of the first embodiment. The collection member (sensible heat storage material) 110 in FIG. 3 has a prismatic shape and is a honeycomb structure in which a plurality of rectangular through holes 111 are formed. However, the collection member 110 is not limited to a prismatic shape, and may be a cylindrical shape. In this case, the through hole is formed so as to penetrate in the axial direction of the column. The shape of the through-hole 111 is not limited to a quadrangle, and may be a polygon such as a circle, an ellipse, or a regular hexagon. The size of the through hole 111 is preferably within a range where the specific surface area is large and no blockage occurs. Specifically, the size of the through hole 111 is about 2 to 10 mm.

The collection member 110 is disposed in the flue 10 so that the extending direction of the through hole 111 substantially coincides with the flow direction of the exhaust gas. SO ₃ removal efficiency of SO ₃ removing apparatus 100 of the first embodiment, the exhaust gas temperature flowing into the SO ₃ removing apparatus 100, SO ₃ concentration in the exhaust gas, the gas flow rate, the temperature of the collection member 110, a sensible heat storage material It varies depending on the specific heat, the specific surface area of the collecting member 110, and the like. The SO ₃ removal apparatus 100 is designed so as to satisfy a desired SO ₃ removal efficiency. Although FIG. 2 shows an example in which one collection member 110 is provided, a plurality of collection members 110 can be arranged in the exhaust gas flow direction in order to obtain a predetermined SO ₃ removal efficiency.
In FIG. 2, a single heat storage material that substantially matches the cross section of the flue 10 is provided as the collecting member 110, but depending on the size of the heat storage material and the flue 10, a direction substantially orthogonal to the exhaust gas distribution direction. It can also be set as the structure which arranged the several heat storage material in the.

In FIG. 2, the cooling unit 120 is installed above the collection member 110 (on the exhaust gas upstream side). However, the cooling unit may be installed below the collection member 110 (on the exhaust gas downstream side).
The cooling unit 120 includes a plurality of nozzles 121 (121-1 to 121-5). Branch nozzles 122 (122-1 to 122-5) are connected to the nozzles 121-1 to 121-5, and valves V1-1 to V1-5 are installed in the branch pipes 122-1 to 122-5, respectively. . The valves V1-1 to V1-5 are installed outside the flue 10. Each branch pipe 122-1 to 122-5 joins the coolant supply pipe 123. The coolant supply pipe 123 is connected to a coolant supply source (not shown). The cooling liquid supply source may be a tank in which the cooling liquid is stored, or may be the storage unit 20 that stores the absorbing liquid sprayed at the bottom of the wet desulfurization apparatus 3. In accordance with the size of the collecting member 110, nozzles and branch pipes are also arranged in the depth direction of the sheet of FIG.

  The cooling unit 120 supplies the coolant from the coolant supply source to the through hole 111 of the collecting member 110 from the nozzles 121-1 to 121-5 via the coolant supply pipe 123 and the branch pipes 122-1 to 122-5. Spray and supply. The coolant can be supplied to the plurality of through holes 111 with one nozzle. The nozzles 121-1 to 121-5 are arranged so that the cooling liquid is supplied to all of the through holes 111 by the plurality of nozzles.

  FIG. 4 is another example of the present embodiment, and is a schematic view of the cooling unit and the collecting member (heat storage material) viewed from the exhaust gas upstream side. In the cooling unit 120 in this modification, the closed end portions 124 of the two branch pipes 122 face each other. A plurality of such combinations of two branch pipes 122 are arranged in a direction substantially orthogonal to the extending direction of the branch pipe 122. A plurality of nozzles 121 are installed in each branch pipe 122. Each branch pipe 122 is provided with a valve outside the flue 10.

As will be described later, the cooling liquid plays a role of cooling the surface of the collecting member 110, which is heated by being exposed to high-temperature exhaust gas, to a sulfuric acid dew point temperature or lower. The cooling liquid is, for example, water, an absorption liquid (slurry containing CaCO ₃ or the like) of the wet desulfurization apparatus 3 and the like. When the absorbing liquid is used as the cooling liquid, the cooling liquid supply source is a tank that stores the storage unit 20 and water, and the absorbing liquid and the water are separately sprayed from the same nozzle. The temperature of the coolant supplied from the cooling unit 120 is not more than the sulfuric acid dew point temperature.
The lower the temperature of the coolant, the better the cooling efficiency. For example, when water is used as the coolant, if the amount of coolant is sufficiently large, the temperature of the coolant approaches the temperature of the environment where the coolant supply source is installed. When using the absorption liquid of the storage part 20 as a cooling liquid, the temperature of a cooling liquid will be about 50-60 degreeC.

  When arranging a plurality of collecting members 110 along the flow direction of the exhaust gas, it is preferable that a cooling unit 120 is provided for each collecting member 110.

A method for removing SO ₃ from exhaust gas using the SO ₃ removing apparatus 100 of the first embodiment will be described below.
The collecting member 110 is cooled below the sulfuric acid dew point temperature. FIG. 5 is an example of a graph showing the relationship between the SO ₃ concentration in the exhaust gas and the acid dew point temperature. In the figure, the horizontal axis represents the SO ₃ concentration, and the vertical axis represents the acid dew point temperature (sulfuric acid dew point temperature). As a method for obtaining the acid dew point at each water content, the Otsuka equation relating to the acid dew point is widely known.

As the SO ₃ concentration increases, the acid dew point temperature increases. Moreover, the acid dew point temperature is higher as the moisture content in the exhaust gas is higher. SO ₃ concentration and the water content in the exhaust gas just before flowing into the SO ₃ removing apparatus 100 is measured by the graph of FIG. 5 from SO ₃ concentration and the moisture content measured, acid exhaust gas flowing into the SO ₃ removing apparatus 100 The dew point temperature (sulfuric acid dew point temperature) is acquired. The collection member 110 is cooled to a temperature sufficiently lower than the acid dew point temperature thus obtained. For example, the collection member 110 before exhaust gas inflow is cooled to 50 to 60 ° C. Cooling of the collection member 110 before the operation of the exhaust gas treatment system is performed by spraying the coolant from the cooling unit 120. Note that the spraying of the coolant from the cooling unit 120 is stopped immediately after the start of the operation of the exhaust gas treatment system.

Exhaust gas containing SO ₃ generated in the combustion facility 2 flows into the SO ₃ removal device 100. In general, operating conditions are set such that the temperature of the exhaust gas before flowing into the SO ₃ removal device 100 is 20 ° C. or more higher than the sulfuric acid dew point. Therefore, although depending on the concentration of SO ₃ , the temperature of the exhaust gas before flowing into the SO ₃ removal device 100 is about 150 to 180 ° C. At this temperature, SO ₃ in front of the exhaust gas flowing into the SO ₃ removing apparatus 100 is present in a gaseous state (SO ₃ gas).

When the temperature of the exhaust gas before flowing into the SO ₃ removal device 100 is higher than the above setting, the flue from the upstream spray device 130 installed in the flue 10 on the exhaust gas upstream side of the SO ₃ removal device 100. It is preferable that cooling water is separately sprayed in advance with respect to the exhaust gas flowing through 10, and the exhaust gas is cooled to a temperature within the range of sulfuric acid dew point to sulfuric acid dew point + 20 ° C. By doing so, it is possible to prevent a rapid temperature rise of the collecting member 110.

(Gas cooling process)
Exhaust gas containing SO ₃ gas flows into the through hole 111 of the collecting member 110. When the exhaust gas comes into contact with the inner wall of the through hole 111 while flowing through the through hole 111, the exhaust gas is cooled. When the exhaust gas temperature is cooled below the sulfuric acid dew point temperature, the SO ₃ gas in the exhaust gas is converted to SO ₃ mist (liquid state). Conversion to mist occurs particularly in the vicinity of the inner wall of the through hole 111. For this reason, the generated mist is easily collected on the inner wall of the through hole 111.

(Collection process)
The SO ₃ mist adheres to the inner wall of the through hole 111 while flowing through the through hole 111 along with the exhaust gas. That is, the SO ₃ mist is collected on the surface of the collecting member 110. As a result, the SO ₃ concentration in the exhaust gas is reduced, and the exhaust gas is discharged from the through hole 111.

  The exhaust gas generated in the combustion facility 2 contains dust. In the present embodiment, part of the dust in the exhaust gas is removed from the exhaust gas by adhering to the collection member 110 and being collected.

(Collecting member cooling process)
FIG. 6 is an example of a result of simulating the temperature change of the heat storage material in the case where the gas cooling step, the collection step, and the collection member cooling step are repeatedly performed. In the figure, the horizontal axis represents time, and the vertical axis represents the temperature of the heat storage material. FIG. 6 shows a calculation result when the exhaust gas flows from the upper part to the lower part of the heat storage material (collecting member 110).

  In the gas cooling process and the collection process, the temperature of the heat storage material increases due to contact with the exhaust gas. Since the upper part of the heat storage material (upstream side of the exhaust gas) is exposed to the exhaust gas having a higher temperature than the lower part of the heat storage material (downstream side of the exhaust gas), the temperature increase width becomes large.

FIG. 6 shows the sulfuric acid dew point temperature (140 ° C.) as an example. When the heat storage material reaches or exceeds the sulfuric acid dew point temperature, SO ₃ mist is not generated. For this reason, the collection member cooling process is performed before the temperature of the heat storage material reaches the sulfuric acid dew point temperature. In the vicinity of the sulfuric acid dew point temperature, the SO ₃ gas is not converted into mist, so the SO ₃ removal efficiency may be reduced. For this reason, the collection member cooling step is preferably performed at a temperature sufficiently lower than the sulfuric acid dew point temperature (for example, the dew point temperature is −80 ° C. to −10 ° C.). However, at the start of the collecting member cooling step, the entire collecting member (heat storage material) does not necessarily have to be below the sulfuric acid dew point temperature. As described above, since there is a temperature range between the upper part (exhaust gas upstream side) and the lower part (exhaust gas downstream side) of the heat storage material, a part (at least the lower part) of the collection member (heat storage material) is below the sulfuric acid dew point temperature and SO. It is sufficient that the conditions are such that ₃ mist can be generated, and the upper part of the collection member (heat storage material) may exceed the sulfuric acid dew point temperature.

  The inner wall of the through hole 111 of the collecting member 110 is cooled to the acid dew point temperature or lower by the coolant. That is, the cooling liquid directly cools the surface of the collecting member 110 on the side where the exhaust gas contacts. The temperature of the collecting member 110 after cooling is set according to the coolant flow rate, the period during which the collecting member cooling step is performed, and the specific heat of the sensible heat storage material.

The timing and period for performing the collecting member cooling step may be set based on a simulation in which the simulation illustrated in FIG. 6 is performed in advance. If the heat capacity of the collection member 110 is large, the temperature rise gradient of the collection member 110 shown in FIG. 6 becomes gentle, so that the time until the collection member 110 reaches the sulfuric acid dew point temperature becomes longer. That is, the time for the gas cooling step and the collection step (interval between the collection member cooling steps) is increased, and the SO ₃ removal efficiency is improved. Moreover, the collection member 110 can be cooled in a shorter time as the temperature of the coolant is lower.

  Alternatively, the temperature of the collecting member 110 during the gas cooling step and the collecting step, particularly the temperature of the exhaust gas upstream side portion of the collecting member 110 is measured, and the collecting member cooling step is performed based on the measured temperature. The timing and period to be implemented may be set.

By carrying out the collecting member cooling step based on the temperature of the collecting member 110 as described above, the temperature of the collecting member 110 while operating the SO ₃ collecting device 100 is kept below the sulfuric acid dew point temperature. Is done.

  If a large amount of coolant flows into the through-hole 111 in order to cool the collecting member in a short time, the ventilation resistance of the exhaust gas increases, and the exhaust gas can almost circulate in the through-hole 111 into which the coolant flows. Disappear. That is, the gas cooling process and the collection process are stopped while the collection member cooling process is being performed. When the coolant is supplied to all the through holes 111, the exhaust gas cannot flow through the flue 10. For this reason, the collecting member cooling step is performed in at least one through-hole 111 among the plurality of through-holes 111, and in the remaining through-holes 111, exhaust gas circulation (gas cooling step and collecting step) needs to be continued. There is.

Specifically, in the SO ₃ removal device 100 of FIG. 2, the valve V1-1 corresponding to the nozzle 121-1 is opened. Thereby, cooling water is supplied toward the collection member 110 from the nozzle 121-1 through the branch pipe 122-1, and a collection member cooling process is performed in the through-hole 111 located under the nozzle 121-1. In the remaining nozzles 121-2 to 121-5, the valves V1-2 to V1-5 are closed, and in the through holes 111 located below the nozzles 121-2 to 121-5, the gas cooling process and the collecting process are performed. Done. When the “period during which the collecting member cooling process is performed” set as described above has elapsed, or when the temperature of the collecting member 110 reaches a predetermined value below the acid dew point, the valve V1-1 is closed. Then, the supply of the coolant is stopped, the exhaust gas is circulated, and the gas cooling process and the collection process are restarted.
By supplying the opening timings of the valves V1-2 to V1-5 to each other, the coolant is sequentially supplied from the nozzles 121-2 to 121-5.

In the modified example of FIG. 4, similarly to the SO ₃ removing device 100 of FIG. 2, the opening and closing of the valve is controlled so that the cooling water is supplied from the nozzle 121 toward the collecting member 110 for each branch pipe 122. The

  In the process described above with reference to FIGS. 2 and 4, the through hole 111 of the collecting member 110 is divided into a plurality of blocks, and the collecting member cooling process is performed for each block. It is realistic to install the cooling unit 120 so as to perform cooling for each block in consideration of the size of the through-hole from which the mist collecting effect is obtained and the space for installing the equipment such as the cooling unit 120. Control of supply becomes easy.

The SO ₃ mist adhering to the inner wall of the through-hole 111 flows toward the lower side of the collecting member 110 along with the flow of the coolant, and is discharged from the collecting member 110. By this collecting member cooling step, the SO ₃ mist is removed from the inner wall of the through hole 111 of the collecting member 110 along with the coolant (the surface of the collecting member 110 is washed). The dust collected by the collection member 110 is also removed from the collection member 110 along with the flow of the coolant together with the SO ₃ mist.
Since the SO ₃ mist on the surface of the collecting member 110 has been removed by the collecting member cooling step, the resumed collecting step makes the mist easily adhere to the surface of the collecting member 110, and the collecting performance is regenerated. Has been. Therefore, it is possible to maintain high SO ₃ removal efficiency over a long period of time.

The coolant that has flowed below the collection member 110 is discharged from the through hole 111 of the collection member 110. In the example of FIG. 2, the discharged coolant flows into the storage unit 20 of the wet desulfurization device 3 through the downstream side flue 11.
When the absorbing liquid is used as the cooling liquid, the cooling liquid discharged from the collection member 110 is circulated to the SO ₃ removal device 100.

When using the absorbing liquid of the wet desulfurization apparatus 3 as the cooling liquid, the absorbing liquid is supplied to the collecting member 110 at the beginning of the collecting member cooling step. Thereafter, the supply of the absorbing liquid is stopped, water is supplied to the collecting member 110, and the absorbing liquid on the surface of the collecting member 110 is washed away. By doing so, the absorbing liquid remains on the surface of the collecting member 110, and when the gas cooling process and the collecting process are restarted, the water in the absorbing liquid evaporates and CaCO ₃ or the like precipitates in the through holes 111. It is possible to prevent the through hole 111 from being blocked.

  Although the example which wash | cleans the collection member 110 was demonstrated above in the cooling liquid, the washing | cleaning part which implements only the washing | cleaning of the collection member 110 may be installed separately from the cooling part 120. FIG.

The temperature of the exhaust gas discharged from the SO ₃ removal device 100 is generally above the water dew point. Therefore, cooling water is sprayed on the exhaust gas flowing through the flue 10 from the downstream spray device 140 installed in the flue 11 on the exhaust gas downstream side of the SO ₃ removal device 100. By so doing, the exhaust gas is cooled to water saturation at which the reaction in the subsequent wet desulfurization apparatus 3 functions sufficiently, that is, to a temperature close to the water dew point (about 50 to 60 ° C.).

Second Embodiment
Figure 7-9 is a diagram for explaining the SO ₃ removing apparatus according to the second embodiment. 7 is a side view, FIG. 8 is a cross-sectional view taken along the line AA in FIG. 7, and FIG. 9 is a cross-sectional view taken along the line BB in FIG.
The SO ₃ removal device 200 is installed in the flue immediately before the wet desulfurization device 3. The flue 10 is installed substantially vertically at the inlet of the wet desulfurization apparatus 3, and the exhaust gas flows through the flue 10 from top to bottom. In addition, you may distribute | circulate waste gas toward the upper direction from the flue 10 shown in FIG.
In addition, the SO ₃ removal device of the present embodiment can be installed in the flue where the exhaust gas circulates in a substantially horizontal direction as long as the effect of the present invention is achieved.

The SO ₃ removal apparatus 200 includes a plurality of SO ₃ collection units 210 and a cooling unit 220.

The SO ₃ collection unit 210 includes a storage unit 211 and a collection member 213. The accommodating part 211 is a rectangular parallelepiped frame 212, and the inside is hollow. The frame body 212 has a plurality of openings through which exhaust gas can flow, and has an opening ratio that does not hinder the flow of exhaust gas. The opening has a size capable of holding the collecting member 213 in the housing portion 211. The material of the accommodating part 211 needs to have acid resistance and heat resistance at the exhaust gas temperature. Specifically, the frame body 212 is made of a punching metal, a wire mesh, a polytetrafluoroethylene mesh member, or the like.

  A sensible heat storage material similar to that of the first embodiment may be used for the collection member 213 of the present embodiment, or a latent heat storage material that uses latent heat associated with the phase change of the substance may be used. The latent heat storage material applicable to the present embodiment is required to have a phase change temperature (melting point) of not higher than the sulfuric acid dew point temperature and a large heat capacity during the phase change. Specifically, it is desirable that the latent heat storage material has characteristics equivalent to erythritol (phase transition temperature 80 to 110 ° C.), sodium acetate trihydrate (phase transition temperature 35 to 57 ° C.), and the like.

  Similar to the first embodiment, the collection member 213 is cooled to the phase change temperature or lower by the coolant supplied from the cooling unit 220. Therefore, the latent heat storage material needs to have a phase change temperature higher than the temperature of the coolant supplied from the cooling unit 220. For example, when water at room temperature is supplied, erythritol or sodium acetate trihydrate can be used as the latent heat storage material. When the absorption liquid (about 50 to 60 ° C.) of the wet desulfurization apparatus 3 is supplied, it is preferable to apply erythritol having a phase transition temperature higher than the coolant temperature as the latent heat storage material.

  These latent heat storage materials are filled in a container such as a capsule made of a resin (for example, polytetrafluoroethylene) having acid resistance and heat resistance to form a collecting member 213. The container is granular. A container shape is not specifically limited, A spherical shape, an elliptical spherical shape, etc. are employable.

  The collection member 213 is filled in the accommodating portion 211. There is a gap through which the exhaust gas can flow between the collection members 213.

A plurality of SO ₃ collection units 210 are arranged in a direction substantially orthogonal to the gas flow direction of the flue 10. Although six SO ₃ collection units 210 are provided in FIG. 7, the present invention is not limited to this. As shown in FIG. 8, the SO ₃ collection unit 210 extends between a pair of opposing wall surfaces 12.
Partition plates 214 a and 214 b are installed between the adjacent SO ₃ collection units 210 and between the SO ₃ collection units 210 at both ends and the wall surface 12 of the flue 10. SO ₃ collecting portion 210, the partition plate 214a, the wall surfaces 12 of 214b and flue 10, an exhaust gas space 215 positioned on the exhaust gas upstream of the SO ₃ collecting portion 210, the exhaust gas downstream of the SO ₃ collecting portion 210 The located processing gas space 216 is isolated.

SO ₃ removal efficiency of SO ₃ removing apparatus 200 of the second embodiment, the exhaust gas temperature flowing into the SO ₃ removing apparatus 200, SO ₃ concentration in the exhaust gas, the gas flow rate, the temperature of the collection member 213, a sensible heat storage material It fluctuates depending on the heat capacity of the specific heat or latent heat storage material, the specific surface area of the collection member 213, the width of the accommodating portion 211 in the exhaust gas flow direction, and the like. The SO ₃ removal apparatus 200 is designed so as to satisfy a desired SO ₃ removal efficiency. For example, it can be configured to include the SO ₃ collecting portion of the plurality of stages in the exhaust gas flow direction.

The cooling unit 220 is installed above the SO ₃ collection unit 210. In the example of FIG. 9, the cooling unit 220 includes a spray pipe 221 (221-1 to 221-6) extending along the SO ₃ collection unit 210. A plurality of discharge holes 222 are provided along the axial direction below the spray pipes 221-1 to 221-6. Instead of the discharge holes 222, a plurality of nozzles may be installed on the exhaust gas upstream side or the exhaust gas downstream side. One end of the spray pipes 221-1 to 221-6 is closed, and valves V2-1 to V2-6 are installed at the other ends of the spray pipes 221-1 to 221-6. The spraying pipes 221-1 to 221-6 merge and are connected to a coolant supply source (not shown). Also in this embodiment, the same kind of coolant as in the first embodiment can be used.
Note that in the embodiment where the exhaust gas flows in a substantially horizontal direction flue, spraying pipe, for example, above the SO ₃ collecting portion, the cooling liquid is disposed in a position that can be supplied to the entire collecting member.

FIG. 10 is a modified example of the SO ₃ removal device of the second embodiment, and is a cross-sectional view taken along the line BB in FIG. In the cooling unit in this modification, two spray pipes 232a (232-1a to 232-6a) and 232b (232-1b to 232-6b) are arranged for one SO ₃ collection unit. The spreading pipes 232a and 232b extend so that the respective closed end portions 231 come into contact with each other in the vicinity of the center portion of the SO ₃ collection portion. Valves V3-1a to V3-6a and V3-1b to V3-6b are installed in the spray pipes 232-1a to 232-6a and 232-1b to 232-6b, respectively. Each of the spray pipes 232-1a to 232-6a and 232-1b to 232-6b joins and is connected to a coolant supply source (not shown).

A method for removing SO ₃ from exhaust gas using the SO ₃ removing apparatus 200 of the second embodiment will be described below.
Similar to the first embodiment, the collection member 213 is cooled to a temperature sufficiently lower than the acid dew point temperature. Cooling of the collection member 213 before the operation of the exhaust gas treatment system is performed by spraying the coolant from the cooling unit 220. Immediately after the start of operation of the exhaust gas treatment system, the spraying of the coolant from the cooling unit 220 is stopped.

The exhaust gas containing SO ₃ gas is cooled within the range of sulfuric acid dew point temperature to sulfuric acid dew point temperature + 20 ° C. before flowing into the SO ₃ removing device 200. By doing so, it is possible to prevent a rapid temperature rise of the collecting member 213.

(Gas cooling process)
Exhaust gas containing SO ₃ gas flows into the exhaust gas space 215 from the inlet and passes through the SO ₃ collection unit 210. The exhaust gas contacts the surface of the collecting member 213 and is cooled while passing through the gap between the collecting members 213. When the exhaust gas temperature is cooled below the sulfuric acid dew point temperature, the SO ₃ gas in the exhaust gas is converted to SO ₃ mist. Conversion to mist occurs particularly in the vicinity of the surface of the collecting member 213. For this reason, the generated mist is easily collected by the collection member 213.

(Collection process)
The generated SO ₃ mist adheres to the surface of the collection member 213 and is collected while passing through the SO ₃ collection unit 210. The exhaust gas having a reduced SO ₃ concentration passes through the SO ₃ trap 210 and reaches the processing gas space 216 and is discharged from the processing gas space 216 through the outlet.
Also in this embodiment, a part of the dust in the exhaust gas is removed from the exhaust gas by adhering to the collection member 213 and being collected.

In the present embodiment, since the exhaust gas will be flowing through the gap between the collecting member 213 increases the frequency of contact between the exhaust gas and the collection member 213, effectively SO ₃ mist generation and SO ₃ mist collecting by gas cooling And can be implemented.

(Collecting member cooling process)
Before the temperature of the collection member 213 reaches the sulfuric acid dew point temperature due to contact with the exhaust gas, the cooling unit 220 supplies the coolant to the collection member 213 of the SO ₃ collection unit 210 from the discharge hole 222. As the cooling liquid flows through the gap between the collecting members 213, the cooling liquid cools the collecting member 213. That is, the cooling liquid directly cools the surface of the collection member 213 on the side where the exhaust gas contacts.

As in the first embodiment, the timing and period for performing the collecting member cooling step may be determined based on the simulation result of the collecting member temperature, and the gas cooling step and the collecting step are performed. It may be determined based on the temperature of the collecting member 213 measured in between. Thus, by implementing the collection member cooling process based on the temperature of the collection member 213, the temperature of the collection member 213 while operating the SO ₃ collection device 200 is maintained below the sulfuric acid dew point temperature. The

In the collecting member cooling step, since the coolant flows through the gap between the collecting members 213, the exhaust gas cannot flow through the SO ₃ collecting unit 210. That is, the gas cooling process and the collection process are stopped while the collection member cooling process is being performed. Also in this embodiment, the collection member cooling step is sequentially performed for each SO ₃ collection unit 210 by shifting the opening timing of the valves V2-1 to V2-6 to each other. In this way, the SO ₃ removal process can be performed continuously.

In the case of the modification of FIG. 10, the valves V3a and V3b of the spray pipes 232a and 232b arranged on the same SO ₃ collection unit may be opened at different times. For example, when the valve V3-1a is opened and the valve V3-1b is closed, the coolant is supplied to the SO ₃ collection unit located below the spray pipe 232-1a, and the flow of the exhaust gas is stopped. . On the other hand, in the SO ₃ collection part located below the spray pipe 232-1b, the exhaust gas flows and the gas cooling process and the collection process are continued.

In the above process, the collecting member 213 is cooled by the coolant, and the SO ₃ mist adhering to the surface of the collecting member 213 is removed. By performing the cooling and the cleaning at the same time as described above, it is possible to lengthen the period for performing the gas cooling process and the collection process, and it is possible to maintain a high SO ₃ removal efficiency over a long period of time.
However, in the present embodiment, a configuration in which a cleaning unit that performs only cleaning of the collection member 213 is installed separately from the cooling unit 220.

<Third Embodiment>
11-12 are views for explaining the SO ₃ removing apparatus according to the third embodiment. 11 is a side view, and FIG. 12 is a cross-sectional view taken along the line CC in FIG.
The SO ₃ removal device 300 is installed at the same location as the SO ₃ removal device of the first embodiment and the second embodiment. The flue 10 is installed substantially vertically at the inlet of the wet desulfurization apparatus 3, and in FIG. 11, the exhaust gas flows through the flue 10 from top to bottom.
In addition, the SO ₃ removal device of the present embodiment can be installed in the flue where the exhaust gas circulates in a substantially horizontal direction as long as the effect of the present invention is achieved.

It is the same as that of 2nd Embodiment except the accommodating part 311 in the SO3 collection part 310 of _3rd Embodiment being cylindrical shape. The housing 311 houses a collecting member using a sensible heat storage material or a latent heat storage material.

A plurality of SO ₃ collection units 310 are arranged in a plane substantially orthogonal to the gas flow direction of the flue 10. In FIG. 11, the SO ₃ collection units 310 are arranged in 3 rows × 3 rows, but the arrangement position is not limited to this.

Partition plates 314 a and 314 b are installed between the SO ₃ collection unit 310 and between the SO ₃ collection unit 310 and the wall surface 12 of the flue 10. SO ₃ collecting portion 310 and the partition plate 314a, by 314b, the exhaust gas space 315 positioned on the exhaust gas upstream of the SO ₃ collecting unit 310, a processing gas space 316 positioned on the exhaust gas downstream of the SO ₃ collecting portion 310 Is isolated.

The cooling unit 320 is installed above each SO ₃ collection unit 310 at a position corresponding to the upper partition plate 314a. 11 and 12 has the same configuration as that of the second embodiment. The cooling unit of the third embodiment is provided with a nozzle on each SO ₃ collection unit (exhaust gas upstream side of the SO ₃ collection unit), for example, and the coolant is supplied to the storage unit of each SO ₃ collection unit. It is good also as a structure.

The SO ₃ removal method using the SO ₃ removal apparatus 300 of the third embodiment is almost the same as the method using the SO ₃ removal apparatus of the second embodiment.

<Fourth embodiment>
13-14 are views for explaining the SO ₃ removing apparatus according to the fourth embodiment. 13 is a side view, and FIG. 14 is a sectional view taken along the line DD in FIG.

The SO ₃ collection unit 410 and the cooling unit 420 in the SO ₃ removal device 400 of FIGS. 13 and 14 are the same as those in the second embodiment.

The SO ₃ removal device 400 of the fourth embodiment is different from the second embodiment and the third embodiment in that a plurality of discharge electrodes 430 are installed in the exhaust gas space 415. As shown in FIG. 14, the discharge electrodes 430 are arranged along the SO ₃ collection unit 410.

The discharge electrode 430 includes a mounting shaft 431 and a plurality of discharge spikes 432 protruding from the mounting shaft 431 in a direction substantially orthogonal to the extending direction of the mounting shaft 431. The tip of the discharge thorn 432 is directed to the surface of the SO ₃ collection unit on the exhaust gas upstream side. Each of the discharge electrodes 430 is connected to a high voltage power source 440.

The member (upstream member) 412 on the upstream side of the exhaust gas of the frame body of the SO ₃ collection unit 410 is made of a conductive material. When the frame is a punching metal or a metal mesh, the upstream member 412 is a metal and has conductivity. When the frame other than the upstream member is a non-conductive member having acid resistance and heat resistance (for example, a member made of polytetrafluoroethylene), the upstream member 412 is made of a conductive material such as punching metal or a metal mesh. To do. The upstream member 412 is grounded.

In the SO ₃ removing device according to the fourth embodiment, the SO ₃ collection unit 410 and the cooling unit 420 may have the same configuration as that of the third embodiment. In this case, one discharge electrode is inserted into the exhaust gas space.

The method for removing SO ₃ from the exhaust gas using the SO ₃ removal apparatus 400 of the _third embodiment is substantially the same as that of the second embodiment. In the fourth embodiment, the SO ₃ removal device actively collects dust contained in the exhaust gas simultaneously with the removal of SO ₃ .

(Charging process)
The high voltage power source applies a voltage to the discharge electrode 430. As a result, a potential difference is generated between the discharge electrode 430 and the upstream member 412, and a corona discharge is generated when a certain potential difference or more is secured between the discharge barb 432 of the discharge electrode 430 and the upstream member 412. To do. Dust in the exhaust gas flowing into the exhaust gas space 415 is charged by corona discharge in the exhaust gas space 415.

(Dust collection process)
The charged dust flows from the exhaust gas flow toward the SO ₃ collection unit 410. The upstream member 412 collects dust charged on the surface. Thereby, dust is removed from the exhaust gas. The exhaust gas from which the dust has been removed passes through the opening of the upstream member 412 and flows into the SO ₃ collection unit 410. Part of the dust that could not be collected by the upstream member 412 is collected from the exhaust gas by being collected by the collection member 413 in the SO ₃ collection unit 410.
By charging the dust as in this embodiment, the dust removal rate from the exhaust gas can be greatly improved.

The dust adhering to the surface of the upstream member 412 flows downward along with the coolant supplied in the collecting member cooling step, and is removed from the upstream member 412. Alternatively, when a cleaning unit is provided separately from the cooling unit 420, dust attached to the surface of the upstream member 412 is removed by the cleaning liquid supplied from the cleaning unit to the SO ₃ collection unit 410.

<Fifth Embodiment>
SO3 removing apparatus according to the fifth embodiment, the SO ₃ removing apparatus described in the first embodiment (FIG. 2), is configured to install the discharge electrode and the dust collecting electrode on the gas upstream side of the collecting member. Hereinafter, the fifth embodiment will be described with reference to FIGS. 2 and 3.

The dust collecting electrode is a plate-like member having an opening through which gas can flow and is made of a conductive material. Specifically, the dust collecting electrode is a metal mesh or punching metal made of a metal or alloy having excellent acid resistance such as Ti, Hastelloy, stainless steel, or a mesh member made of carbon fiber.
The dust collection electrode is installed on the surface of the collection member 110 that is a heat storage body that faces the flow of exhaust gas. The dust collecting electrode is grounded.

  The discharge electrode is installed to face the dust collection electrode. The discharge electrode has the same configuration as the discharge electrode 430 of the fourth embodiment. The tip of the discharge thorn of the discharge electrode is directed to the dust collection electrode. It is preferable that a plurality of discharge spikes be installed on one mounting shaft. In FIG. 2, it is preferable to have a configuration in which a plurality of discharge electrodes are arranged in the depth direction or the horizontal direction. The discharge electrode is connected to a high voltage power source.

The method for removing SO ₃ from the exhaust gas using the SO ₃ removal apparatus of the fifth embodiment is substantially the same as that of the first embodiment.
In the fifth embodiment, dust contained in the exhaust gas is collected simultaneously with the removal of SO _{3 in} the SO ₃ removal device.

(Charging process)
The high-voltage power supply applies a voltage to the discharge electrode and generates a potential difference between the discharge electrode and the dust collection electrode. Thereby, corona discharge is generated between the discharge thorn of the discharge electrode and the dust collection electrode. Dust in the exhaust gas flowing into the SO ₃ removal device is charged by corona discharge.

(Dust collection process)
The charged dust flows from the exhaust gas flow toward the dust collecting electrode. The dust collecting electrode collects dust charged on the surface. Thereby, dust is removed from the exhaust gas. The exhaust gas from which the dust has been removed passes through the opening of the dust collecting electrode and flows through the through hole 111 in the collecting member 110. Part of the dust that could not be collected by the dust collection electrode is removed from the exhaust gas by being collected by the collection member 110.
By charging the dust as in the present embodiment, the dust removal rate from the exhaust gas can be significantly improved as compared with the first embodiment.

  The dust adhering to the surfaces of the dust collecting electrode and the collecting member 110 flows downward along with the coolant supplied in the collecting member cooling step, and is removed from the dust collecting electrode and the collecting member 110. When a cleaning unit is provided separately from the cooling unit 120, dust attached to the surfaces of the dust collecting electrode and the collecting member 110 is removed by the cleaning liquid supplied from the cleaning unit to the collecting member 110.

<Sixth Embodiment>
FIG. 15 is a schematic view of an SO ₃ removal device according to the sixth embodiment. In FIG. 15, the same components as those in FIG.
The SO ₃ removal device 500 of the sixth embodiment includes a collecting member 510 installed in the flue 10, a cooling unit 520, a cleaning unit 530, and a temperature measuring unit 540.

  A heat transfer body is used for the collecting member 510. The heat transfer body applied to this embodiment has high thermal conductivity (for example, 10 W / (m · K) or more) and has acid resistance. Specifically, the collection member (heat transfer body) 510 is made of a metal such as Ti, an alloy such as Hastelloy or stainless steel, SiC, or carbon fiber.

The collection member 510 in the present embodiment is a honeycomb structure in which a plurality of through holes are formed, similarly to the heat storage material shown in FIG. The collection member 510 is disposed in the flue 10 so that the extending direction of the through hole substantially coincides with the flow direction of the exhaust gas.
The SO ₃ removal device 500 is installed in the flue immediately before the wet desulfurization device 3. The flue 10 is installed substantially vertically at the inlet of the wet desulfurization apparatus 3, and the exhaust gas flows through the flue 10 from top to bottom. Note that the exhaust gas may circulate from the bottom to the top of the flue 10 shown in FIG. In addition, the SO ₃ removal device of the present embodiment can be installed in the flue where the exhaust gas circulates in a substantially horizontal direction as long as the effect of the present invention is achieved.

  The shape of the collecting member 510 is not particularly limited, and has a shape corresponding to the cross-sectional shape of the flue 10 such as a prism or cylinder. The shape of the through hole is not particularly limited, and is, for example, a polygon such as a quadrangle or a regular hexagon, a circle house, or an ellipse. As in the case of the heat storage material, the size of the through hole is preferably within a range where the specific surface area is large and no blockage is caused. Specifically, the size of the through hole is about 2 to 10 mm.

The SO ₃ removal efficiency is the exhaust gas temperature flowing into the SO ₃ removal device 500, the SO ₃ concentration in the exhaust gas, the gas flow rate, the temperature of the collection member 510, the thermal conductivity of the heat transfer member, the specific surface area of the collection member 510, and the like. Varies depending on The SO ₃ removal apparatus 500 is designed so as to satisfy a desired SO ₃ removal efficiency.
Although FIG. 15 shows a configuration in which one heat transfer body is provided as the collecting member 510, the direction substantially perpendicular to the exhaust gas flow direction or the flow direction of the exhaust gas depending on the size of the heat transfer body and the size of the flue 10. It is good also as a structure which puts in order a some heat exchanger.

In FIG. 15, the cooling part 520 is installed above the collection member 510 (exhaust gas upstream side). However, the cooling unit may be installed below the collection member 510 (on the exhaust gas downstream side).
The cooling unit 520 has a plurality of nozzles 521, and a branch pipe 522 is connected to each nozzle 521. Although five nozzles 521 are shown in FIG. 15, the number of nozzles 521 is not limited to this. Depending on the size of the collecting member 510, nozzles and branch pipes are also arranged in the depth direction of the paper in FIG. Each branch pipe 522 joins the coolant supply pipe 523. A valve V4 is installed in the coolant supply pipe 523 outside the flue 10. The coolant supply pipe 523 is connected to a coolant supply source (not shown). The coolant supply source may be a tank or the storage unit 20 of the wet desulfurization apparatus 3.

  When arranging a plurality of collecting members 510 along the flow direction of the exhaust gas, it is preferable that a cooling unit 520 is provided for each collecting member 510.

The cooling unit 520 sprays the coolant from the nozzle 521 toward the collecting member 510. Although high-temperature exhaust gas is circulating inside the SO ₃ removal device 500, in order for the collecting member 510 to be cooled by the cooling liquid, the sprayed droplets of the cooling liquid must reach the collecting member 510. I must. The time required until the droplet (water) completely evaporates depends on the droplet diameter. Therefore, considering the droplet diameter of the coolant sprayed from the nozzle 521, the gas flow rate, etc., the tip of the nozzle 521 and the collection member 510 are arranged so that the cleaning liquid reaches the collection member 510 as droplets. The distance is set.

In FIG. 15, the cleaning unit 530 is installed above the collection member 510 (on the exhaust gas upstream side). However, the cleaning unit may be installed below the collection member 510 (on the exhaust gas downstream side).
The cleaning unit 530 includes a nozzle 531, a branch pipe 532, and a cleaning liquid supply pipe 533. The plurality of nozzles 532 are respectively connected to the branch pipe 532, and the branch pipe 532 joins the cleaning liquid supply pipe 533. Each branch pipe 532 is provided with a valve V <b> 5 outside the flue 10. The cleaning liquid supply pipe 533 is connected to a cleaning liquid supply source (not shown). The cleaning liquid supply source may be a tank or the storage unit 20 of the wet desulfurization apparatus 3.

  As illustrated in FIG. 4, the cleaning unit 530 may be combined so that the closed ends of the two branch pipes face each other.

  The temperature measuring unit 540 is attached to the collecting member 510 and measures the surface temperature of the collecting member 510. A plurality of temperature measuring units 540 may be attached to one collecting member 510. In this case, it is preferable that the plurality of temperature measurement units 540 can measure the temperature distribution in the gas circulation direction by measuring the temperature of the collection member 510 at a plurality of locations along the exhaust gas circulation direction. Moreover, the temperature measurement part 540 may be arrange | positioned so that the temperature distribution of the collection member 510 in the several location in the surface substantially orthogonal to an exhaust gas distribution direction may be measured.

A method for removing SO ₃ from exhaust gas using the SO ₃ removal apparatus 500 of the sixth embodiment will be described below.
Before the operation of the exhaust gas treatment system, the collection member 510 is cooled to a sulfuric acid dew point temperature or lower (for example, 50 to 60 ° C.). Cooling of the collection member 510 before operation is performed by spraying the coolant from the nozzle 521 of the cooling unit 520 to the collection member 510.

Similarly to the first embodiment, when the temperature of the exhaust gas before flowing into the SO ₃ removal device 500 exceeds 150 to 180 ° C., the upstream installed in the flue 10 on the exhaust gas upstream side of the SO ₃ removal device 500. It is preferable that cooling water is separately sprayed in advance with respect to the exhaust gas flowing through the flue 10 from the side spray device 130, and the exhaust gas is cooled to a temperature within the range of sulfuric acid dew point to sulfuric acid dew point + 20 ° C.

(Gas cooling process)
Exhaust gas (150 to 180 ° C.) containing SO ₃ gas flows into the SO ₃ removal device 100 and circulates in the through hole of the collecting member 510. Since the collection member 510 is cooled below the sulfuric acid dew point temperature, the exhaust gas is cooled by contacting the inner wall of the through hole while the exhaust gas flows through the through hole. When the exhaust gas temperature is cooled below the sulfuric acid dew point temperature, the SO ₃ gas in the exhaust gas is converted into SO ₃ mist very close to the inner wall of the through hole.

(Collection process)
The SO ₃ mist generated in the very vicinity of the inner wall of the through-hole adheres to the inner wall of the through-hole while flowing through the through-hole along with the exhaust gas, and is collected by the collecting member 510. The exhaust gas from which the SO ₃ mist has been removed passes through the through hole and is discharged from the collecting member 510.

  The exhaust gas generated in the combustion facility 2 contains dust. In this embodiment, a part of the dust in the exhaust gas is removed from the exhaust gas by being collected by the collection member 510.

(Collecting member cooling process)
When the high-temperature exhaust gas comes into contact with the collection member (heat transfer body) 510, the temperature of the collection member 510 rises at the contact portion.
In the sixth embodiment, the collecting member cooling step is continued between the gas cooling step and the collecting step. While the exhaust gas is flowing through the collection member 510, the coolant is sprayed. The spray of cooling water may be continuous or intermittent. The coolant sprayed from the nozzle 521 of the cooling unit 520 reaches the collecting member 510 in a droplet state while part of the coolant evaporates while cooling the exhaust gas. The cooling liquid droplets completely evaporate on the collecting member 510, specifically on the inner wall of the through hole. The collection member 510 is cooled by the heat of vaporization of the coolant. Since the collecting member 510 is a heat transfer body, not only the location where the coolant contacts but also the surrounding area is cooled by the coolant. The cooling unit 520 sprays the cooling liquid substantially uniformly on the entire collecting member 510, whereby the temperature of the collecting member 510 can be made substantially uniform.

  In this embodiment, the temperature measurement part 540 measures the temperature of the collection member 510 between a gas cooling process and a collection process. The cooling unit 520 controls the supply amount of the coolant based on the temperature measured by the temperature measurement unit 540. By doing so, the cooling unit 520 maintains the temperature of the collecting member 510 below the sulfuric acid dew point temperature.

(Washing process)
Since the coolant evaporates on the collecting member 510 as described above, SO ₃ mist accumulates on the surface of the collecting member 510 when the collecting process is continued. For this reason, in this embodiment, the washing | cleaning part 530 supplies a washing | cleaning liquid toward the collection member 510 regularly, and the collection member 510 is wash | cleaned. The collected dust is also removed from the collecting member 110 together with the cleaning liquid.

  In the cleaning process, a sufficient amount of cleaning liquid is supplied from the cleaning unit 530 so as not to completely evaporate on the collection member 510. Since the exhaust gas cannot pass through the through hole into which the cleaning liquid flows, the gas cooling process and the collection process are stopped. For this reason, the cleaning process is performed in at least one of the plurality of through holes of the collection member 510, and the circulation of the exhaust gas (the gas cooling process and the collection process) is continued in the remaining through holes. Actually, as described in the collecting member cooling step of the first embodiment, the through hole of the collecting member 510 is divided into a plurality of blocks, and the cooling step is periodically performed for each block.

Specifically, in the SO ₃ removal device 500 of FIG. 15, the cleaning liquid is sequentially supplied from the nozzle 531 by shifting the opening timing of the plurality of valves V5. The timing for performing the cleaning process and the period of the cleaning process are set in consideration of the SO ₃ concentration in the exhaust gas, the gas flow rate, the size of the collection member 510, and the like.

The SO ₃ mist adhering to the inner wall of the through hole is removed from the collecting member 510 by flowing toward the lower side of the collecting member 510 along with the flow of the cleaning liquid. When the cleaning process is completed and the exhaust gas can flow through the through-hole, the inner wall of the through-hole is in a state where SO ₃ mist easily adheres, and the collection performance is regenerated. Therefore, it is possible to maintain high SO ₃ removal efficiency over a long period of time.

When using the absorbing liquid of the wet desulfurization apparatus 3 as the cleaning liquid, the absorbing liquid is supplied to the collecting member 110 at the beginning of the cleaning process. Thereafter, the supply of the absorbing liquid is stopped, water is supplied to the collecting member 110, and the absorbing liquid on the surface of the collecting member 110 is washed away. By doing so, the absorbing liquid remains on the surface of the collecting member 110, and when the gas cooling process and the collecting process are restarted, moisture in the absorbing liquid evaporates and CaCO _{3 and the} like are deposited in the through holes. It is possible to prevent the through hole from being blocked.

The SO ₃ mist is discharged from below the collecting member 510 together with the cleaning liquid. The discharged cleaning liquid flows into the storage unit 20 of the wet desulfurization apparatus 3 through the flue 11. Therefore, when the absorption liquid of the wet desulfurization apparatus 3 is used as the cleaning liquid, the cleaning liquid discharged from the collection member 510 is circulated to the SO ₃ removal apparatus 500.

The temperature of the exhaust gas discharged from the SO ₃ removal device 500 is generally equal to or higher than the water dew point temperature. For this reason, like the SO ₃ removal device of the first embodiment, the cooling water is sprayed from the downstream spray device 140 to the exhaust gas flowing through the flue 10, and the exhaust gas is at a temperature close to the water dew point temperature (about 50 ˜60 ° C.).

<Seventh embodiment>
FIG. 16 is a side view for explaining the SO ₃ removing device according to the seventh embodiment. The SO ₃ removal device 600 of the seventh embodiment includes a collection member 610, a cooling unit 620, a cleaning unit 630, and a temperature measurement unit 640. The SO ₃ removal apparatus 600 of the seventh embodiment is the same as the SO ₃ removal apparatus of the sixth embodiment except that the cooling unit is different. The collecting member 610 is provided apart from the wall surface 12 of the flue 10. The cooling unit 620 in the SO ₃ removal device 600 of the seventh embodiment is installed in the flue 10 on the side surface (the outer peripheral surface along the exhaust gas flow direction) of the collection member 610 that is a heat transfer body.
In FIG. 16, the exhaust gas flows through the flue 10 from top to bottom. In the present embodiment, the exhaust gas may circulate through the flue 10 from the bottom to the top. In addition, the SO ₃ removal device of the present embodiment can be installed in the flue where the exhaust gas circulates in a substantially horizontal direction as long as the effect of the present invention is achieved.

  A side surface of the collecting member 610 is surrounded by a partition wall 650. The collection member 610 and the partition 650 are in contact with each other. The partition wall 650 is a member having high thermal conductivity, acid resistance, and heat resistance. Specifically, it is a plate made of a metal such as Ti or an alloy such as Hastelloy or stainless steel.

  The cooling unit 620 includes a plurality of nozzles 621 installed in a space between the inner wall of the flue 10 and the collecting member 610 (partition wall 650), a plurality of branch pipes 622 connected to each nozzle 621, and a valve V6. Prepare. Each branch pipe 622 joins and communicates with a cooling water supply pipe (not shown). The tip position of the nozzle 621 is determined so that cooling water can be supplied to the side surface of the collecting member 610. A plurality of nozzles 621 may be installed around the collection member 610 and may be arranged in the exhaust gas flow direction.

  A shielding member 651 that obstructs gas flow between the exhaust gas upstream side surface of the collection member 610 and the wall surface 12 of the flue 10 so that the exhaust gas does not flow into the space between the flue 10 and the collection member 610. Is installed.

The method for removing SO ₃ from the exhaust gas using the SO ₃ removal device 600 of the seventh embodiment is the same as that of the sixth embodiment except for the method of cooling the collection member. Also in this embodiment, a part of the dust in the exhaust gas is removed from the exhaust gas by being collected by the collection member 610.
In the seventh embodiment, the cooling unit 620 supplies the coolant to the partition wall 650 in the case where the collecting member 610 is cooled before operation and in the collecting member cooling step. Since the collection member 610 of this embodiment is a heat transfer body, the temperature of the other part of the collection member 610 also decreases as the surface of the collection member 610 in contact with the coolant is cooled. As a result, the inner wall of the through hole of the collecting member 610 is cooled below the sulfuric acid dew point temperature. That is, the coolant supplied from the cooling unit 620 indirectly cools the inner wall of the through hole, which is a region where SO ₃ mist is collected.

  Also in the present embodiment, the supply of the cooling liquid from the cooling unit 620 is continued while the gas cooling process and the collection process are performed.

  Similar to the sixth embodiment, the temperature measurement unit 640 measures the temperature of the collection member 610. The cooling unit 620 controls the supply amount of the coolant based on the measured temperature. By doing so, the cooling unit 620 maintains the temperature of the collecting member 610 below the sulfuric acid dew point temperature.

  When the collection member 610 is large, a temperature distribution is generated in the collection member 610 even if the side surface of the collection member 610 is cooled by the cooling unit 620. Depending on the thermal conductivity of the collection member (heat transfer body), the size of the collection member, the exhaust gas temperature, the temperature of the coolant, and the amount of coolant, the temperature below the sulfuric acid dew point temperature is maintained at the center of the collection member 610. It may not be possible. In this case, by installing the same configuration as the cooling unit 620 in FIG. 15 in the flue 10 and supplying the coolant to the collecting member 610, the temperature of the entire collecting member 610 can be surely lower than the sulfuric acid dew point temperature. To maintain.

<Eighth Embodiment>
FIG. 17 is a side view for explaining the SO ₃ removing device according to the eighth embodiment.
The SO ₃ removal device 700 of the eighth embodiment is a heat transfer body in which the collection member 710 has a plurality of through holes, and the plurality of collection members 710 are substantially orthogonal to the direction in which the exhaust gas flows in the flue 10. They are spaced apart in the direction. The collecting member 710 is disposed away from the wall surface 12 of the flue 10. Although three collection members 710 are shown in FIG. 17, the number of collection members 710 is not limited to this in this embodiment.
In FIG. 17, the exhaust gas flows through the flue 10 from top to bottom. In the present embodiment, the exhaust gas may circulate through the flue 10 from the bottom to the top. In addition, the SO ₃ removal device of the present embodiment can be installed in the flue where the exhaust gas circulates in a substantially horizontal direction as long as the effect of the present invention is achieved.

In FIG. 17, each collecting member 710 is surrounded by a partition wall 750. A shielding member 751 that inhibits the flow of gas between the exhaust gas upstream side surface of the collection member 710 and the wall surface 12 of the flue 10 so that the exhaust gas does not flow into the space between the flue 10 and the collection member 710. Is installed.
A cooling unit 720 </ b> A similar to that of the seventh embodiment is installed between the space between the collection members 710 and between the collection member 710 and the wall surface of the flue 10. In addition, a cooling unit 720B similar to that of the sixth embodiment is installed above the collection member 710 (on the exhaust gas upstream side). The cooling unit 720 </ b> B may be installed below the collection member 710.
A temperature measuring unit 740 is installed on each collecting member 710.

  In FIG. 17, a cleaning unit 730 is installed above the collection member 710 (exhaust gas upstream side). In the eighth embodiment, the cleaning unit 730 is provided with a nozzle 731 for each of the collection members 710. Each nozzle 731 is connected to a branch pipe 732. A valve V <b> 7 is installed in each branch pipe 732 outside the flue 10.

A method for removing SO ₃ from exhaust gas using the SO ₃ removal apparatus 700 of the eighth embodiment will be described below. The gas cooling step and the collection step in this embodiment are substantially the same as those in the sixth embodiment. Also in this embodiment, a part of the dust in the exhaust gas is removed from the exhaust gas by being collected by the collection member 710.

  In the case where the collecting member 710 is cooled before the operation and in the collecting member cooling step, the cooling unit 720 supplies the coolant to the partition wall 750. Thereby, the cooling unit 720 indirectly cools the surface (through hole inner wall) of the collection member 710 that contacts the exhaust gas. Further, the exhaust gas supplied from the cooling unit 710 to the collecting member 710 directly contacts the through hole inner wall of the collecting member 710 to cool the through hole inner wall. As a result, the collection member 710 is cooled below the sulfuric acid dew point temperature.

  The cooling unit 720 </ b> A and the cooling unit 720 </ b> B control the supply amount of the cooling water based on the temperature measured by the temperature measurement unit 740 to maintain the collection member 710 below the sulfuric acid dew point temperature.

  Note that FIG. 17 shows a configuration in which two cooling units 720A and 720B are installed, but in the present embodiment, either one of the cooling unit 720A and the cooling unit 720B may be installed.

In the present embodiment, the cleaning process is performed for each collection member 710. Specifically, in the SO ₃ removing device 700 of FIG. 17, the supply of the cleaning liquid from the nozzle 731 is sequentially performed by shifting the opening timing of the valve V7. In the collecting member 710 in which the cleaning process is performed, the SO ₃ mist and dust collected by the collecting member 710 are discharged from the collecting member 710 together with the cleaning liquid. In the collection member 710 where the cleaning process is performed, the flow of the exhaust gas is blocked, but in the other collection member 710, the flow of the exhaust gas is continued, and the gas cooling process and the collection process are performed. Therefore, it is possible to maintain high SO ₃ removal efficiency over a long period of time while continuing the flow of exhaust gas.

<Ninth Embodiment>
FIG. 18 is a side view for explaining the SO ₃ removing device according to the ninth embodiment.
The SO ₃ removal apparatus 800 of this embodiment includes a cooling unit 820, a cleaning unit 830, and a temperature measurement unit 840 having the same configuration as that of the sixth embodiment. In FIG. 18, the exhaust gas flows through the flue 10 from top to bottom. In the present embodiment, the exhaust gas may circulate through the flue 10 from the bottom to the top. In addition, the SO ₃ removal device of the present embodiment can be installed in the flue where the exhaust gas circulates in a substantially horizontal direction as long as the effect of the present invention is achieved.

  The collection member 810 of the ninth embodiment is a heat transfer body having acid resistance, and has a mesh-shaped opening. The collection member 810 is, for example, a metal mesh or punching metal manufactured from a metal or alloy having excellent acid resistance such as Ti, Hastelloy, or stainless steel, or a mesh member made of carbon fiber.

In the present embodiment, a plurality of plate-like collection members 810 may be stacked in the exhaust gas flow direction. The plate-shaped collection member 810 is disposed so that the surface having the opening faces the flow of exhaust gas.
In the present embodiment, a plate-shaped collecting member formed in a cylindrical shape may be disposed.

FIG. 19 is a view showing a modification of the SO ₃ removal device according to the ninth embodiment. FIG. 19 is a side view. In FIG. 19, the exhaust gas flows through the flue 10 from the top to the bottom. In the present embodiment, the exhaust gas may circulate through the flue 10 from the bottom to the top.
In the SO ₃ removal device 900 of this modification, the plate-shaped collection member 910 is disposed so as to be inclined with respect to the flow direction of the exhaust gas. In FIG. 19, two collecting members 910a and 910b support the load on the upper side, and are combined so that the longitudinal section becomes a triangle. However, this modification is not limited to this, and the shape of the longitudinal section may be another polygon such as a trapezoid. Although the SO ₃ removal apparatus 900 of FIG. 19 is configured to include six, the number of the collection members 910 is not limited to this. When a plurality of collecting members 910 are installed, the collecting members 910 are arranged in a direction substantially orthogonal to the flow direction of the exhaust gas. The collecting member 910 is installed on a support portion (not shown).
A temperature measuring unit 940 is attached to each collecting member 910.

In the SO ₃ removal apparatus 900 of this modification, the branch pipe 922 of the cooling unit 920 is disposed along each collection member 910. In the example of FIG. 19, the branch pipe 922 may be installed also in the depth direction of the paper. The plurality of branch pipes 922 join the cooling water supply pipe 923. A plurality of nozzles 921 are installed in each branch pipe 922. The tip of the nozzle 921 is directed to the collecting member 910.

  The configuration of the cleaning unit 930 is the same as that of the sixth embodiment. In FIG. 19, the nozzle 931 is installed above the combined portion of the two collecting members 910. For example, the nozzle 931a is installed above the combined portion of the collection members 910a and 910b.

  However, the cleaning unit 930 is not limited to the upper side of the collecting member 910 and may be installed below the collecting member 910. In this case, the nozzle 931 of the cleaning unit 930 is preferably arranged at a position where the cleaning liquid can be supplied to the entire collection member 910.

Note that the SO ₃ removal device having the configuration shown in FIG. 19 can also be installed in a flue through which exhaust gas flows in a substantially horizontal direction. In this case, the combination part of the collection member is directed in a direction substantially coincident with the exhaust gas circulation direction. The cooling unit and the cleaning unit are installed on the upstream side of the exhaust gas of the collection member. However, about a washing | cleaning part, it can be set as the structure installed above a collection member.

The SO ₃ removal method according to the ninth embodiment will be described using the SO ₃ removal apparatus 800 shown in FIG.
Prior to the operation of the exhaust gas treatment system, the collection member 810 is cooled to below the sulfuric acid dew point temperature by the cooling unit 820.

(Gas cooling process)
Exhaust gas (150 to 180 ° C.) containing SO ₃ gas flows into the SO ₃ removal device 800. Since the collection member 810 is cooled below the sulfuric acid dew point temperature, the exhaust gas is cooled by contacting the collection member 810 when the exhaust gas passes through the opening of the collection member 810. When the exhaust gas temperature is cooled below the sulfuric acid dew point temperature, the SO ₃ gas in the exhaust gas is converted into SO ₃ mist in the immediate vicinity of the mesh-shaped collecting member 810.

(Collection process)
The SO ₃ mist generated in the very vicinity of the collecting member 810 is collected by the collecting member 810 by adhering to the surface of the collecting member 810. The exhaust gas from which the SO ₃ mist has been removed passes through the opening of the collection member 810 and is discharged from the collection member 810. Part of the dust in the exhaust gas is removed from the exhaust gas by being collected by the collection member 810.

(Collecting member cooling process)
Also in this embodiment, the collection member cooling process is continued between the gas cooling process and the collection process. The coolant sprayed from the nozzle 821 of the cooling unit 820 reaches the collecting member 810 in a droplet state and evaporates on the collecting member 810. Since the collection member 810 is a heat transfer body, the portion in contact with the coolant and the surrounding region are cooled by the heat of vaporization of the coolant. The cooling unit 820 sprays the cooling liquid substantially uniformly on the entire collection member 810, so that the temperature of the collection member 810 is substantially uniform.
The temperature of the collecting member 810 during the gas cooling step and the collecting step is measured. The cooling unit 820 controls the supply amount of the coolant based on the measured temperature, and maintains the temperature of the collection member 810 below the sulfuric acid dew point temperature.

Also in the SO ₃ removal apparatus 900 of the modification of FIG. 19, the SO ₃ removal process is performed by the gas cooling step, the collection step, and the collection member cooling step similar to the above.

(Washing process)
Also in the present embodiment, the cleaning process is periodically performed. Through the cleaning process, SO ₃ mist and dust adhering to the collecting member 810 are removed from the surface of the collecting member 810 together with the cleaning liquid.

When the flat surface of the plate-shaped collection member 810 is arranged so as to face the flow of exhaust gas as in the SO ₃ removal device 800 of FIG. 18, the flat surface is divided into a plurality of areas, and a cooling process is performed for each area. Is performed regularly. Specifically, the supply of the cleaning liquid from the nozzle 821 is sequentially performed by shifting the opening / closing timing of the valve V8. By doing so, in one plate-shaped collection member 810, there are an area where the flow of exhaust gas is blocked and the cooling process is performed, and an area where the gas cooling process and the collection process are performed. To do. As a result, the SO ₃ removal process can be performed continuously.

In the SO ₃ removal apparatus 900 of the modification shown in FIG. 19, the cooling process is performed for each collection member 910. In the example of FIG. 19, when the cooling liquid is supplied from the nozzle 921a, the cooling process is performed by the collecting members 910a and 910b located below the nozzle 921a. On the other hand, the SO ₃ removal process is continued in the other collection members 910c to 910f.

<Tenth Embodiment>
FIG. 20 is a diagram for explaining the SO ₃ removal device according to the tenth embodiment. FIG. 20 is a side view. In FIG. 20, the exhaust gas flows through the flue 10 from the top to the bottom. In the present embodiment, the exhaust gas may circulate through the flue 10 from the bottom to the top. In addition, the SO ₃ removal device of the present embodiment can be installed in the flue where the exhaust gas circulates in a substantially horizontal direction as long as the effect of the present invention is achieved.

The SO ₃ removal apparatus 1000 according to the tenth embodiment includes a plurality of SO ₃ collection units 1010 as in the SO ₃ removal apparatus described in the second embodiment. A plurality of SO ₃ collection units 1010 are arranged in a direction substantially orthogonal to the gas flow direction.

Similar to the second embodiment, the SO ₃ collection unit 1010 includes an accommodation unit 1011 and a collection member 1013. The accommodating part 1011 is comprised by the rectangular parallelepiped frame 1012, and the inside is a cavity. The frame body 1012 has a plurality of openings through which exhaust gas can flow. Specifically, the frame body 1012 is made of a punching metal, a wire mesh, a polytetrafluoroethylene mesh member, or the like.

A collecting member 1013 is accommodated in the accommodating portion 1011. In the tenth embodiment, the collection member 1013 is a granular heat transfer body. As described in the sixth embodiment, the heat transfer body is made of a metal such as Ti, an alloy such as Hastelloy or stainless steel, SiC, or carbon fiber.
A temperature measuring unit 1040 is attached to each collecting member 1010.

A branch pipe 1022 of the cooling unit 1020 is disposed along the SO ₃ collection unit 1010. In the example of FIG. 20, the branch pipe 1022 may be installed in the depth direction of the paper. The plurality of branch pipes 1022 join the cooling water supply pipe 1023. A plurality of nozzles 1021 are installed in each branch pipe 1022. The tip of the nozzle 1021 is directed to the collecting member 1013.

The cleaning unit 1030 is installed above the SO ₃ collection unit 1010. In the case of installing the SO ₃ removing apparatus of this embodiment flue flowing substantially horizontally exhaust gas, spraying pipe of the cleaning unit can be configured to be disposed above the collecting member.
The cleaning unit 1030 in the present embodiment can have the same configuration (FIGS. 9 and 10) as the cooling unit in the second embodiment. That is, the cleaning unit 1030 has a configuration in which a plurality of discharge holes are provided in the spraying pipe extending along the SO ₃ collection unit 1010, and a valve is installed in the spraying pipe. In this case, the cleaning unit 1030 is installed on the exhaust gas upstream side of the SO ₃ collection unit 1010.

As a modification of the tenth embodiment, the SO ₃ collection unit may be cylindrical as in the third embodiment (FIGS. 11 and 12).

In the method for removing SO ₃ from the exhaust gas using the SO ₃ removal apparatus 1000 of the tenth embodiment, the gas cooling step, the collecting step, and the collecting member cooling step are substantially the same as in the sixth embodiment. Also in this embodiment, a part of the dust in the exhaust gas is removed from the exhaust gas by being collected by the collection member 1013.

In the cleaning process of the tenth embodiment, the cleaning unit 1030 supplies cleaning water to the collecting member 1013 from the discharge hole or the valve. Thereby, the SO ₃ mist and dust collected by the collection member 1013 are discharged from the collection member 1013 together with the cleaning liquid. At this time, by performing the cleaning process for each SO ₃ collection unit 1010, the gas cooling process, the collection process, and the cleaning process can be performed simultaneously in the SO ₃ removal apparatus 1000. As a result, the SO ₃ removal process can be performed continuously.

<Eleventh embodiment>
FIG. 21 is a diagram for explaining the SO ₃ removal device according to the eleventh embodiment. FIG. 21 is a side view.
The SO ₃ removal device 1100 according to the eleventh embodiment includes a collection member 1110, a cooling unit 1120, a cleaning unit 1130, and a temperature measurement unit 1140 that are the same as the SO ₃ removal device described in the sixth embodiment. The SO ₃ removal apparatus 1100 further includes a discharge electrode 1150, a dust collection electrode 1170, and a high voltage power source 1160.
In FIG. 21, the exhaust gas flows through the flue 10 from top to bottom. In the present embodiment, the exhaust gas may circulate through the flue 10 from the bottom to the top. In addition, the SO ₃ removal device of the present embodiment can be installed in the flue where the exhaust gas circulates in a substantially horizontal direction as long as the effect of the present invention is achieved.

The discharge electrode 1150, the dust collection electrode 1170, and the high voltage power supply 1160 have the same configuration as in the fifth embodiment.
As shown in FIG. 21, a dust collection electrode 1170 is installed on the surface of the collection member 1110 that faces the exhaust gas. The dust collection electrode 1170 is a plate-like member having an opening through which gas can flow and is made of a conductive material. Specifically, the dust collection electrode 1170 is a metal mesh or punching metal made of an acid-resistant metal or alloy such as Ti, Hastelloy, or stainless steel, or a mesh member made of carbon fiber.

  The discharge electrode 1150 is disposed to face the dust collection electrode 1170. The discharge electrode 1150 has a mounting shaft 1151 and a plurality of discharge spikes 1152 protruding from the mounting shaft 1151 in a direction substantially orthogonal to the extending direction of the mounting shaft 1151. The tip of the discharge thorn 1152 is directed to the dust collection electrode 1170. In FIG. 21, a plurality of discharge electrodes 1150 may be arranged in the depth direction of the paper. The discharge electrode 1150 is connected to a high voltage power source 1160. The dust collection electrode 1170 is grounded.

A method for removing SO ₃ from exhaust gas using the SO ₃ removal apparatus 1100 of the eleventh embodiment is substantially the same as that of the sixth embodiment.
In the eleventh embodiment, dust contained in the exhaust gas is collected simultaneously with the removal of SO _{3 in} the SO ₃ removal device.

(Charging process)
The high voltage power supply 1160 applies a voltage to the discharge electrode 1150 and generates a potential difference between the discharge electrode 1150 and the dust collection electrode 1170. Thereby, corona discharge is generated between the discharge thorn 1152 of the discharge electrode 1150 and the dust collection electrode 1170. The dust in the exhaust gas flowing into the SO ₃ removal device 1100 is charged by corona discharge.

(Dust collection process)
The charged dust flows from the exhaust gas flow toward the dust collection electrode 1170. The dust collecting electrode 1170 collects dust charged on the surface. Thereby, dust is removed from the exhaust gas. The exhaust gas from which the dust has been removed passes through the opening of the dust collecting electrode 1170 and flows through the through hole in the collecting member 1110. Part of the dust that could not be collected by the dust collection electrode 1170 is collected from the exhaust gas by being collected by the collection member 1110.
By charging the dust as in the present embodiment, the dust removal rate from the exhaust gas can be significantly improved as compared with the SO ₃ removal device of the sixth embodiment.

  In the case of the present embodiment, the cleaning liquid supplied from the cleaning unit 1130 in the cleaning process takes in the dust attached to the dust collecting electrode 1170 and flows toward the collecting member 1110. Thereby, dust is removed from the dust collection electrode 1170.

The process of removing dust from the exhaust gas described in the present embodiment is performed in the same manner in the SO ₃ removal apparatuses of the seventh and eighth embodiments.

<Twelfth embodiment>
FIG. 22 is a view for explaining an SO ₃ removal device according to the twelfth embodiment. FIG. 22 is a side view.
The SO ₃ removal device 1200 of FIG. 22 includes a collection member 1210, a cooling unit 1220, a cleaning unit 1230, and a temperature measurement unit 1240 similar to those of the SO ₃ removal device of FIG. The SO ₃ removal apparatus 1200 further includes a discharge electrode 1250 and a high voltage power source 1260.
As described above, the collection member 1210 is made of metal (conductive material). Therefore, in this embodiment, the collection member 1210 serves as a dust collection electrode.
In FIG. 22, the exhaust gas flows through the flue 10 from the top to the bottom. In the present embodiment, the exhaust gas may circulate through the flue 10 from the bottom to the top. In addition, the SO ₃ removal device of the present embodiment can be installed in the flue where the exhaust gas circulates in a substantially horizontal direction as long as the effect of the present invention is achieved.

  The discharge electrode 1250 is installed to face the collecting member 1210. The discharge electrode 1250 has a mounting shaft 1251 and a discharge thorn 1252. The tip of the discharge thorn 1252 is directed to the collection member 1210. In FIG. 22 as well, a plurality of discharge electrodes 1250 may be arranged in the depth direction of the paper. The discharge electrode 1250 is connected to a high voltage power source 1260. The collecting member 810 is grounded.

FIG. 23 is a view for explaining an SO ₃ removal device according to a modification of the twelfth embodiment. FIG. 23 is a side view.
The SO ₃ removal device 1300 in FIG. 23 includes a collection member 1310, a cooling unit, a cleaning unit 1330, and a temperature measurement unit that are substantially the same as the SO ₃ removal device in FIG. In order to simplify the drawing, the cooling unit and the temperature measuring unit are omitted in FIG. The SO ₃ removal apparatus 1300 further includes a discharge electrode 1350 and a high voltage power source (not shown in FIG. 23).
Also in FIG. 23, the exhaust gas flows through the flue 10 from the top to the bottom, but the exhaust gas may flow through the flue 10 from the bottom to the top. In addition, the SO ₃ removal device of the present embodiment can be installed in the flue where the exhaust gas circulates in a substantially horizontal direction as long as the effect of the present invention is achieved.

Also in this modification, the collection member 1310 serves as a dust collection electrode.
The discharge electrode 1350 has a mounting shaft 1351 and a discharge bar 1352. The mounting shaft 1351 is disposed along each collecting member 1310. The tip of the discharge thorn 1352 is directed to the collection member 1310. Also in FIG. 23, a plurality of discharge electrodes 1350 may be arranged in the depth direction of the drawing. The discharge electrode 1350 is connected to a high voltage power source 1360. The collecting member 1310 is grounded.

The method of removing SO ₃ from the exhaust gas using the SO ₃ removal apparatuses 1200 and 1300 of the twelfth embodiment is substantially the same as that of the ninth embodiment.
In the twelfth embodiment, the method of collecting dust in the SO ₃ removal apparatuses 1200 and 1300 is substantially the same as the method described in the eleventh embodiment.
According to this embodiment, dust charged by corona discharge adheres to the collecting members 1210 and 1310 and is collected, thereby being removed from the exhaust gas. If the SO ₃ removal device of the present embodiment is used, the dust removal rate from the exhaust gas can be greatly improved as compared with the SO ₃ removal device of the ninth embodiment.

<13th Embodiment>
FIG. 24 is a view for explaining an SO ₃ removal device according to the thirteenth embodiment. FIG. 24 is a side view.
Similar to the SO ₃ removal device of the tenth embodiment, the SO ₃ removal device 1400 of the thirteenth embodiment includes an SO ₃ collection unit 1410, a cooling unit, a cleaning unit 1430, and a temperature measurement unit. In order to simplify the drawing, the cooling unit and the temperature measuring unit are omitted in FIG. The SO ₃ removal apparatus 1400 further includes a discharge electrode 1450 and a high voltage power source (not shown in FIG. 24).
In FIG. 24, the exhaust gas flows through the flue 10 from top to bottom. In the present embodiment, the exhaust gas may circulate through the flue 10 from the bottom to the top. In addition, the SO ₃ removal device of the present embodiment can be installed in the flue where the exhaust gas circulates in a substantially horizontal direction as long as the effect of the present invention is achieved.

When the frame body of the SO ₃ collection unit 1410 is a punching metal or a metal mesh, the exhaust gas upstream side member (upstream side member) 1412 of the frame body 1012 is a metal and has conductivity. When the frame is a non-conductive member (for example, a member made of polytetrafluoroethylene), the upstream member 1412 of the frame is made of a conductive material such as punching metal or metal mesh. The upstream member 1412 is grounded. The upstream member 1412 serves as a dust collection electrode.

  A discharge electrode 1450 is installed in the exhaust gas space 1415. The discharge electrode 1450 has a mounting shaft 1451 and a discharge bar 1452, and the tip of the discharge bar 1452 is directed to the upstream member 1412. The discharge electrode 1450 is connected to a high voltage power source. On the other hand, the upstream member 1412 is grounded.

When the SO ₃ collection part is cylindrical as in the third embodiment (FIGS. 11 and 12), one discharge electrode is inserted into the exhaust gas space.

The method of removing SO ₃ from the exhaust gas using the SO ₃ removal apparatus 1400 of the thirteenth embodiment is substantially the same as the tenth embodiment.
In the thirteenth embodiment, the method for collecting dust in the SO ₃ removal device 1400 is substantially the same as the method described in the eleventh embodiment.

Also in the present embodiment, the dust in the exhaust gas is removed from the exhaust gas by adhering to the collection member 1410 and being collected. If the SO ₃ removal device of the present embodiment is used, the dust removal rate from the exhaust gas can be significantly improved as compared with the SO ₃ removal device of the tenth embodiment.

1 Exhaust gas treatment system 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400 SO ₃ removal device 110, 213, 510, 610, 710, 810, 910, 1013 , 1110, 1210, 1310 Collection member 111 Through-hole 120, 220, 320, 420, 520, 620, 720, 820, 920, 1020, 1120, 1220 Cooling unit 210, 310, 410, 1010, 1410 SO ₃ collection Portions 211, 311 and 1011 Housing portions 215, 315, 415 and 1415 Exhaust gas spaces 216 and 316 Process gas spaces 412 and 1412 Upstream members 530, 630, 730, 830, 930, 1030, 1130, 1230, 1330 and 1430 Cleaning units 430, 11 50, 1250, 1350, 1450 Discharge electrode

Claims (36)

An SO ₃ removal device provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows,
A collection member that is cooled to a sulfuric acid dew point temperature or lower, cools the exhaust gas to generate the mist containing SO ₃ , and collects the mist;
Based on the temperature of the collecting member, a cooling unit for maintaining the collecting member below the sulfuric acid dew point temperature ,
The collection member is a sensible heat storage material made of ceramics,
The collecting member is a honeycomb structure having a column shape and having a plurality of through holes formed therein,
The through hole is formed so as to penetrate in the axial direction of the column of the collecting member,
The SO ₃ removal device , wherein the collection member is disposed in the flow passage so that an extending direction of the through hole substantially coincides with a flow direction of the exhaust gas in the flow passage . An SO ₃ removal device provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows,
A collection member that is cooled to a sulfuric acid dew point temperature or lower, cools the exhaust gas to generate the mist containing SO ₃ , and collects the mist;
Based on the temperature of the collecting member, a cooling unit for maintaining the collecting member below the sulfuric acid dew point temperature ,
The SO ₃ removing device, wherein the collection member is a latent heat storage material having a melting point equal to or lower than the sulfuric acid dew point temperature . An SO ₃ removal device provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows,
A collection member that is cooled to a sulfuric acid dew point temperature or lower, cools the exhaust gas to generate the mist containing SO ₃ , and collects the mist;
A partition wall that surrounds the side surface of the collecting member and is arranged to contact the collecting member;
Based on the temperature of the collecting member, a cooling unit for maintaining the collecting member below the sulfuric acid dew point temperature ,
The collection member is a heat transfer body having acid resistance,
The SO ₃ removal apparatus in which the cooling unit supplies a cooling liquid to the side surface of the partition wall, and indirectly cools the surface of the heat transfer body on the side where the cooling liquid contacts the exhaust gas . The SO ₃ removing device according to claim 1 or 2 , wherein a cooling liquid is supplied to a surface of the collecting member on a side where the cooling unit comes into contact with the exhaust gas, and the cooling liquid directly cools the surface. The SO ₃ removing device according to claim 4 , wherein the mist collected by the collecting member is removed from the collecting member. The SO ₃ removing apparatus according to claim 3 , further comprising a cleaning unit that supplies a cleaning liquid to the collection member. The has a collecting member a plurality of through-holes, said exhaust gas is the flow in the through-hole, according to any of claims 1, 3 and 4 for collecting the mist on the inner wall of the through hole SO ₃ removal device. A plurality of SO ₃ traps, each of which is composed of a storage section having a plurality of openings and the granular collection member filled in the storage section, are arranged in a direction substantially perpendicular to the flow direction of the exhaust gas in the flow passage. Have a collection
The SO ₃ collecting unit, the SO ₃ and an exhaust gas space in which the exhaust gas located on an upstream side of the exhaust gas collector flows, located downstream of the exhaust gas of the SO ₃ collecting portion the SO ₃ Isolate the processing gas space into which the processing gas from which the mist has been removed flows in the collecting section,
The SO ₃ removal device according to claim 2 or 3 , wherein a plurality of the cooling units are installed corresponding to each of the SO ₃ collection units. An SO ₃ removal device provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows,
A collection member that is cooled to a sulfuric acid dew point temperature or lower, cools the exhaust gas to generate the mist containing SO ₃ , and collects the mist;
Based on the temperature of the collecting member, a cooling unit for maintaining the collecting member below the sulfuric acid dew point temperature ,
A plurality of openings each having a plurality of openings and the granular collection member filled in the storage, and arranged in a manner spaced apart in a direction substantially perpendicular to the flow direction of the exhaust gas in the flow passage. An SO ₃ collection unit,
The SO ₃ collecting unit, the SO ₃ and an exhaust gas space in which the exhaust gas located on an upstream side of the exhaust gas collector flows, located downstream of the exhaust gas of the SO ₃ collecting portion the SO ₃ Isolate the processing gas space into which the processing gas from which the mist has been removed flows in the collecting section,
A plurality of the cooling unit, the SO ₃ collector SO ₃ removing apparatus installed in correspondence to each. The said collection member is a member which has a mesh-shaped opening, The said collection member cools the said waste gas when the said waste gas passes through the said opening, The said collection member collects the said mist. 3. The SO ₃ removing device according to ₃ . An SO ₃ removal device provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows,
A collection member that is cooled to a sulfuric acid dew point temperature or lower, cools the exhaust gas to generate the mist containing SO ₃ , and collects the mist;
A cooling unit disposed along the collection member and configured to supply a coolant and maintain the collection member below the sulfuric acid dew point temperature based on the temperature of the collection member; ,
The collection member is a heat transfer body having acid resistance,
The collection member is a member having a mesh-shaped opening, and when the exhaust gas passes through the opening, the collection member cools the exhaust gas, and the collection member collects the mist,
The collection member is plate-shaped, and is disposed to be inclined with respect to the flow direction of the exhaust gas.
More the collection member is, SO ₃ removing apparatus which is an array in a direction substantially perpendicular to the flow direction of the exhaust gas in the flow passage. The exhaust gas contains dust,
A discharge electrode is disposed on the upstream side of the exhaust gas of the collecting member,
A dust collection electrode having an opening through which the exhaust gas can flow is arranged on the upstream side of the exhaust gas of the collecting member,
The SO ₃ removal apparatus according to claim 1 or 7 , wherein the discharge electrode generates corona discharge to charge the dust, and the dust collection electrode collects the charged dust. An SO ₃ removal device provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows ,
A collection member that is cooled to a sulfuric acid dew point temperature or lower, cools the exhaust gas to generate the mist containing SO ₃ , and collects the mist;
Based on the temperature of the collecting member, a cooling unit for maintaining the collecting member below the sulfuric acid dew point temperature,
Supplying cooling liquid to the surface of the collecting member on the side where the cooling unit contacts the exhaust gas, and the cooling liquid directly cools the surface;
The collection member has a plurality of through-holes, the exhaust gas is circulated in the through-holes, and the mist is collected on an inner wall of the through-holes;
The exhaust gas contains dust,
A discharge electrode is disposed on the upstream side of the exhaust gas of the collecting member,
A dust collection electrode having an opening through which the exhaust gas can flow is arranged on the upstream side of the exhaust gas of the collecting member,
An SO ₃ removing device that collects the dust charged by the dust collecting electrode by charging the dust by causing the discharge electrode to generate corona discharge. The exhaust gas contains dust,
The upstream member facing the upstream side of at least the exhaust gas of the accommodating portion is a conductive material,
A discharge electrode is disposed in the exhaust gas space;
The SO ₃ removal apparatus according to claim 8 or 9 , wherein the discharge electrode generates corona discharge to charge the dust, and the upstream member collects the charged dust. The exhaust gas contains dust,
The collection member is made of a conductive material,
A discharge electrode is disposed on the upstream side of the exhaust gas of the collecting member,
The SO ₃ removal device according to claim 10 or 11 , wherein the discharge electrode generates corona discharge to charge the dust, and the collecting member collects the charged dust. An SO ₃ removal device provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows ,
A collection member that is cooled to a sulfuric acid dew point temperature or lower, cools the exhaust gas to generate the mist containing SO ₃ , and collects the mist;
Based on the temperature of the collecting member, a cooling unit for maintaining the collecting member below the sulfuric acid dew point temperature,
The collection member is a heat transfer body having acid resistance,
The collection member is a member having a mesh-shaped opening, and when the exhaust gas passes through the opening, the collection member cools the exhaust gas, and the collection member collects the mist,
The exhaust gas contains dust,
The collection member is made of a conductive material,
A discharge electrode is disposed on the upstream side of the exhaust gas of the collecting member,
An SO ₃ removing device in which the discharge electrode generates corona discharge to charge the dust and the collecting member collects the charged dust. The SO ₃ removing device according to any one of claims 1 to 16 ,
An exhaust gas treatment system comprising a wet desulfurization device provided on the downstream side of the exhaust gas of the SO ₃ removal device. A method of removing the SO ₃ from the exhaust gas using an SO ₃ removal device that is provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows, and that includes a collection member and a cooling unit,
The collection member cooled to a sulfuric acid dew point temperature or less and the exhaust gas containing SO ₃ in a gaseous state are in contact with each other, and the exhaust gas is cooled to the sulfuric acid dew point temperature or less to produce a mist containing the SO ₃ ; ,
A step of collecting the mist on the surface of the collecting member;
The cooling unit is seen containing a step of maintaining said collecting member based on the temperature of the collecting member below the sulfuric acid dew point,
The collection member is a sensible heat storage material made of ceramics,
The collecting member is a honeycomb structure having a column shape and having a plurality of through holes formed therein,
The through hole is formed so as to penetrate in the axial direction of the column of the collecting member,
The SO ₃ removal method , wherein the collection member is disposed in the flow passage so that an extending direction of the through hole substantially coincides with a flow direction of the exhaust gas in the flow passage . A method of removing the SO ₃ from the exhaust gas using an SO ₃ removal device that is provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows, and that includes a collection member and a cooling unit,
The collection member cooled to a sulfuric acid dew point temperature or less and the exhaust gas containing SO ₃ in a gaseous state are in contact with each other, and the exhaust gas is cooled to the sulfuric acid dew point temperature or less to produce a mist containing the SO ₃ ; ,
A step of collecting the mist on the surface of the collecting member;
The cooling unit is seen containing a step of maintaining said collecting member based on the temperature of the collecting member below the sulfuric acid dew point,
The SO ₃ removal method, wherein the collection member is a latent heat storage material having a melting point equal to or lower than the sulfuric acid dew point temperature . A method of removing the SO ₃ from the exhaust gas using an SO ₃ removal device that is provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows, and that includes a collection member and a cooling unit,
The collection member cooled to a sulfuric acid dew point temperature or less and the exhaust gas containing SO ₃ in a gaseous state are in contact with each other, and the exhaust gas is cooled to the sulfuric acid dew point temperature or less to produce a mist containing the SO ₃ ; ,
A step of collecting the mist on the surface of the collecting member;
The cooling unit is seen containing a step of maintaining said collecting member based on the temperature of the collecting member below the sulfuric acid dew point,
Further comprising a partition wall that surrounds the side surface of the collection member and is arranged to contact the collection member;
The collection member is a heat transfer body having acid resistance,
The SO ₃ removal method, wherein the cooling unit supplies a cooling liquid to the side surface of the partition wall and indirectly cools the surface of the heat transfer body with the cooling liquid . The SO ₃ removal method according to claim 18 or 19 , wherein a cooling liquid is supplied to a surface of the collecting member on a side where the cooling unit comes into contact with the exhaust gas, and the surface is directly cooled by the cooling liquid. The method for removing SO _{3 according} to claim 21 , wherein the mist collected by the collecting member is removed from the collecting member. 21. The SO ₃ removal method according to claim 20 , wherein a cleaning liquid is supplied to the collecting member, and the mist collected by the collecting liquid is removed from the collecting member. The collecting member has a plurality of through holes;
The exhaust gas is cooled by flowing through each of the through holes, and the mist is generated.
The SO ₃ removal method according to any one of claims 18 , 20 , and 21 , wherein the mist is collected on an inner wall of the through hole. The cooling unit supplies cooling liquid to at least one of the through holes to cool the surface of the through hole;
Simultaneously with cooling of the at least one through hole, the exhaust gas flows through the remaining through hole,
25. The SO ₃ removal method according to claim 18 or 24, wherein when the at least one through hole is cooled, the exhaust gas flows through the at least one through hole. The SO ₃ removal device is configured by a storage portion having a plurality of openings and the granular collection member filled in the storage portion, and is arranged in a direction substantially orthogonal to the flow direction of the exhaust gas in the flow passage. A plurality of SO ₃ collectors,
The SO ₃ collecting unit, the SO ₃ and an exhaust gas space in which the exhaust gas located on an upstream side of the exhaust gas collector flows, located downstream of the exhaust gas of the SO ₃ collecting portion the SO ₃ Isolate the processing gas space into which the processing gas from which the mist has been removed flows in the collecting section,
The exhaust gas is cooled by flowing from the exhaust gas space into the SO ₃ collection unit and flowing between the collection members,
21. The SO ₃ removal method according to claim 19 or 20 , wherein the mist is collected on a surface of the collection member, and the processing gas is discharged from the SO ₃ collection unit to the processing gas space. A method of removing the SO ₃ from the exhaust gas using an SO ₃ removal device that is provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows, and that includes a collection member and a cooling unit,
The collection member cooled to a sulfuric acid dew point temperature or less and the exhaust gas containing SO ₃ in a gaseous state are in contact with each other, and the exhaust gas is cooled to the sulfuric acid dew point temperature or less to produce a mist containing the SO ₃ ; ,
A step of collecting the mist on the surface of the collecting member;
The cooling section includes maintaining the collection member below the sulfuric acid dew point temperature based on the temperature of the collection member;
The SO ₃ removal device includes a housing portion having a plurality of openings and the granular collection member filled in the housing portion, and is separated in a direction substantially orthogonal to the flow direction of the exhaust gas in the flow passage. A plurality of SO ₃ collectors arranged as
The SO ₃ collecting unit, the SO ₃ and an exhaust gas space in which the exhaust gas located on an upstream side of the exhaust gas collector flows, located downstream of the exhaust gas of the SO ₃ collecting portion the SO ₃ Isolate the processing gas space into which the processing gas from which the mist has been removed flows in the collecting section,
The exhaust gas is cooled by flowing from the exhaust gas space into the SO ₃ collection unit and flowing between the collection members,
The SO ₃ removal method in which the mist is collected on the surface of the collection member, and the processing gas is discharged from the SO ₃ collection unit to the processing gas space . A plurality of the cooling units are installed corresponding to each of the plurality of SO ₃ collection units,
The cooling unit supplies cooling liquid to at least one SO ₃ collection unit to cool the collection member;
The same time at least one cooling of the SO ₃ collecting portion, said remaining of said SO ₃ collector exhaust gas flows,
28. The SO ₃ removal method according to claim 26 or 27, wherein after the cooling of the at least one SO ₃ collection unit is completed, the exhaust gas flows through the at least one SO ₃ collection unit. A method of removing the SO ₃ from the exhaust gas using an SO ₃ removal device that is provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows, and that includes a collection member and a cooling unit ,
The collection member cooled to a sulfuric acid dew point temperature or less and the exhaust gas containing SO ₃ in a gaseous state are in contact with each other, and the exhaust gas is cooled to the sulfuric acid dew point temperature or less to produce a mist containing the SO ₃ ; ,
A step of collecting the mist on the surface of the collecting member;
The cooling section includes maintaining the collection member below the sulfuric acid dew point temperature based on the temperature of the collection member;
Supplying cooling liquid to the surface of the collecting member on the side where the cooling unit comes into contact with the exhaust gas, and directly cooling the surface with the cooling liquid;
The SO ₃ removal device is configured by a storage portion having a plurality of openings and the granular collection member filled in the storage portion, and is arranged in a direction substantially orthogonal to the flow direction of the exhaust gas in the flow passage. A plurality of SO ₃ collectors,
The SO ₃ collecting unit, the SO ₃ and an exhaust gas space in which the exhaust gas located on an upstream side of the exhaust gas collector flows, located downstream of the exhaust gas of the SO ₃ collecting portion the SO ₃ Isolate the processing gas space into which the processing gas from which the mist has been removed flows in the collecting section,
The exhaust gas is cooled by flowing from the exhaust gas space into the SO ₃ collection unit and flowing between the collection members,
The mist is collected on the surface of the collection member, and the processing gas is discharged from the SO ₃ collection unit to the processing gas space,
A plurality of the cooling units are installed corresponding to each of the plurality of SO ₃ collection units,
The cooling unit supplies cooling liquid to at least one SO ₃ collection unit to cool the collection member;
The same time at least one cooling of the SO ₃ collecting portion, said remaining of said SO ₃ collector exhaust gas flows,
Wherein the cooling of the at least one SO ₃ collecting portion is completed, the SO ₃ removing wherein said at least one SO ₃ collecting portion the exhaust gas flows. The collecting member is a member having a mesh-shaped opening;
21. The SO ₃ removal method according to claim 20 , wherein when the exhaust gas passes through the opening, the collection member cools the exhaust gas and collects the mist. A method of removing the SO ₃ from the exhaust gas using an SO ₃ removal device that is provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows, and that includes a collection member and a cooling unit,
The collection member cooled to a sulfuric acid dew point temperature or less and the exhaust gas containing SO ₃ in a gaseous state are in contact with each other, and the exhaust gas is cooled to the sulfuric acid dew point temperature or less to produce a mist containing the SO ₃ ; ,
A step of collecting the mist on the surface of the collecting member;
The cooling unit having a pipe for supplying a cooling liquid disposed along the collecting member maintains the collecting member below the sulfuric acid dew point based on the temperature of the collecting member; Including
The collection member is a heat transfer body having acid resistance,
The collection member is a member having a mesh-shaped opening, and when the exhaust gas passes through the opening, the collection member cools the exhaust gas, and the collection member collects the mist,
The collection member is plate-shaped, and is disposed to be inclined with respect to the flow direction of the exhaust gas.
SO ₃ removal method plurality of said collecting member, which is an array in a direction substantially perpendicular to the flow direction of the exhaust gas in the flow passage.
The exhaust gas contains dust,
A discharge electrode is disposed on the upstream side of the exhaust gas of the collecting member,
A dust collection electrode having an opening through which the exhaust gas can flow is arranged on the upstream side of the exhaust gas of the collecting member,
Corona discharge is generated in the upstream space of the exhaust gas of the collection member by the discharge electrode, and the dust is charged;
The method for removing SO _{3 according} to claim 18 or 24, further comprising a step of collecting the charged dust on a surface of the dust collecting electrode. A method of removing the SO ₃ from the exhaust gas using an SO ₃ removal device that is provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows, and that includes a collection member and a cooling unit ,
The collection member cooled to a sulfuric acid dew point temperature or less and the exhaust gas containing SO ₃ in a gaseous state are in contact with each other, and the exhaust gas is cooled to the sulfuric acid dew point temperature or less to produce a mist containing the SO ₃ ; ,
A step of collecting the mist on the surface of the collecting member;
The cooling section includes maintaining the collection member below the sulfuric acid dew point temperature based on the temperature of the collection member;
Supplying cooling liquid to the surface of the collecting member on the side where the cooling unit comes into contact with the exhaust gas, and directly cooling the surface with the cooling liquid;
The collecting member has a plurality of through holes;
The exhaust gas is cooled by flowing through each of the through holes, and the mist is generated.
The mist is collected on the inner wall of the through hole,
The exhaust gas contains dust,
A discharge electrode is disposed on the upstream side of the exhaust gas of the collecting member,
A dust collection electrode having an opening through which the exhaust gas can flow is arranged on the upstream side of the exhaust gas of the collecting member,
Corona discharge is generated in the upstream space of the exhaust gas of the collection member by the discharge electrode, and the dust is charged;
Further comprising SO ₃ removal method and a step of charged the dust is collected on the surface of the dust collecting electrode. The exhaust gas contains dust,
A discharge electrode is disposed in the exhaust gas space of the SO ₃ removal device, and an upstream member facing at least an upstream side of the exhaust gas of the accommodating portion is a conductive material,
Corona discharge is generated in the exhaust gas space by the discharge electrode, and the dust is charged;
30. The SO ₃ removal method according to any one of claims 26 , 27, and 29, further comprising a step of collecting the charged dust on a surface of the upstream member. The exhaust gas contains dust,
The collection member is made of a conductive material, and a discharge electrode is disposed on the upstream side of the exhaust gas of the collection member,
Corona discharge is generated in the upstream space of the exhaust gas of the collection member by the discharge electrode, and the dust is charged;
The SO ₃ removal method according to claim 30 or 31 , further comprising a step of collecting the charged dust on a surface of the collection member. A method of removing the SO ₃ from the exhaust gas using an SO ₃ removal device that is provided in a flow passage through which exhaust gas containing SO ₃ in a gaseous state flows, and that includes a collection member and a cooling unit ,
The collection member cooled to a sulfuric acid dew point temperature or less and the exhaust gas containing SO ₃ in a gaseous state are in contact with each other, and the exhaust gas is cooled to the sulfuric acid dew point temperature or less to produce a mist containing the SO ₃ ; ,
A step of collecting the mist on the surface of the collecting member;
The cooling section includes maintaining the collection member below the sulfuric acid dew point temperature based on the temperature of the collection member;
The collection member is a heat transfer body having acid resistance,
The collecting member is a member having a mesh-shaped opening;
When the exhaust gas passes through the opening, the collecting member cools the exhaust gas, collects the mist,
The exhaust gas contains dust,
The collection member is made of a conductive material, and a discharge electrode is disposed on the upstream side of the exhaust gas of the collection member,
Corona discharge is generated in the upstream space of the exhaust gas of the collection member by the discharge electrode, and the dust is charged;
Further comprising SO ₃ removal method and a step of charged the dust is collected on the surface of the collecting member.

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