JP6794917B2 - Exhaust gas treatment method, exhaust gas treatment equipment, glass article manufacturing equipment and glass article manufacturing method - Google Patents

Description

The present invention relates to an exhaust gas treatment method, an exhaust gas treatment device, a glass article manufacturing apparatus, and a glass article manufacturing method.

The exhaust gas generated in the glass melting furnace contains various components derived from the fuel used to melt the glass raw material, the glass raw material, and the like. For example, when heavy oil is used to dissolve a glass raw material by a flame, a sulfur component is contained in the exhaust gas. Further, in the case of producing borosilicate glass, a boron component is contained in the exhaust gas. If these components are released into the atmosphere as they are, they may have an adverse effect on the environment. Therefore, various methods for removing these components from exhaust gas have been studied.

Patent Document 1 describes a method of adding a solid alkali metal carbonate and / or a solid alkali metal hydrogen carbonate to an exhaust gas containing a boron component to remove the boron component in the exhaust gas.

Further, in Patent Document 2, as a method for removing the sulfur component and the boron component in the exhaust gas, the exhaust gas is brought into contact with cooling water and contact water, and the sulfur component and the boron component in the exhaust gas are dissolved in water and removed. The method is described. The effluent containing sulfur and boron components produced by this method can be reused as cooling water or contact water after being neutralized.

Japanese Unexamined Patent Publication No. 2003-10633 International Publication No. 2009/072612

However, since the method described in Patent Document 1 is an exhaust gas treatment method using a dry exhaust gas treatment facility, the boron component in the exhaust gas may not be sufficiently removed.

Further, the method described in Patent Document 2 can sufficiently remove the boron component in the exhaust gas and reuse the waste liquid as cooling water or contact water, but the wet equipment provided after the bag filter becomes bloated and the investment cost is increased. , There is a problem that operating costs are high.

The present invention has been made in view of the above problems, and is an exhaust gas treatment method and exhaust gas that can sufficiently remove sulfur components, boron components, etc. in exhaust gas, and can suppress investment costs and operating costs of wet equipment. Provided are a processing apparatus, a glass article manufacturing apparatus, and a glass article manufacturing method.

The present invention comprises a glass melting step of melting a glass raw material, a cooling step of bringing a cooling aqueous solution into contact with the exhaust gas generated in the glass melting step to obtain a cooled exhaust gas, and an alkali metal salt or alkaline soil in the cooled exhaust gas. A powder recovery step of recovering the reaction product of the cooled exhaust gas and the powder as a powder while contacting the powders of metal salts to obtain post-contact exhaust gas, and contacting the post-contact exhaust gas with a cooling liquid. The effluent treatment step includes a effluent treatment step of recovering the reaction liquid of the exhaust gas and the cooling liquid as effluent while obtaining clean gas, and the effluent treatment step prepares the effluent at pH 5-9. A treatment liquid is produced by adjusting the temperature to 40 ° C. or higher, the treatment liquid is sent back to the cooling step, and the cooling step is an exhaust gas treatment method characterized in that the treatment liquid is brought into contact with the exhaust gas. ..

Further, the present invention is an exhaust gas treatment device including a glass melting furnace for generating exhaust gas, a cooling tower, a bag filter, and a scrubber, and the cooling tower sprays a cooling aqueous solution on the exhaust gas. The bag filter includes a filter cloth and a powder recovery means for obtaining exhaust gas after cooling, and the filter cloth carries a powder of an alkali metal salt or an alkaline earth metal salt, and after cooling. The exhaust gas is brought into contact with the powder to form a post-contact exhaust gas, the powder recovery means recovers the reaction product of the cooled exhaust gas and the powder as a powder, and the scrubber is a cooling liquid in the post-contact exhaust gas. Is provided with a nozzle for obtaining clean gas and drainage liquid by spraying, an adjusting means for adjusting the pH and temperature of the drainage liquid to be a treatment liquid, and a return pipe for sending the treatment liquid to the cooling tower. The cooling tower is an exhaust gas treatment device including a nozzle for spraying the treatment liquid on the exhaust gas.

According to the exhaust gas treatment method, the exhaust gas treatment device, the glass article manufacturing apparatus, and the glass article manufacturing method of the present invention, the sulfur component, boron component, etc. in the exhaust gas can be sufficiently removed and discharged by a simple wet facility. The liquid can be reused.

It is the schematic of the exhaust gas treatment apparatus which concerns on one Embodiment of this invention. A cooling tower according to an embodiment of the present invention, (A) is a schematic cross-sectional view of an enlarged main part of the cooling tower, and (B) is a plan view of the cooling tower. It is the schematic of the scrubber which concerns on one Embodiment of this invention. It is a flowchart which shows the exhaust gas treatment method which concerns on one Embodiment of this invention.

Hereinafter, the exhaust gas treatment apparatus, the exhaust gas treatment method, the glass article manufacturing apparatus, and the glass article manufacturing method according to the embodiment of the present invention will be described with reference to the drawings. The scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention.

[Exhaust gas treatment equipment]
FIG. 1 is a schematic view of an exhaust gas treatment device according to an embodiment of the present invention. 2A and 2B are a cooling tower according to an embodiment of the present invention, in which FIG. 2A is an enlarged sectional view of a main part of the cooling tower, and FIG. 2B is a plan view of the cooling tower.

The exhaust gas treatment device 1 according to the embodiment of the present invention will be described with reference to FIG.

The exhaust gas treatment device 1 of the present embodiment includes a glass melting furnace 10 that generates exhaust gas G1, a cooling tower 20, a bag filter 30, a powder supply device 35, a denitration device 40, a scrubber 50, and a main fan 60. , With a chimney 70.

The glass melting furnace 10 heats and melts the glass raw material by radiating the flame of the burner toward the glass raw material to generate exhaust gas G1. Burners form flames by mixing fuels such as natural gas and heavy oil with gas and burning them. As the burner, an air combustion burner that mainly uses air as a gas or an oxygen combustion burner that mainly uses oxygen as a gas is used.

Exhaust gas G1 contains a sulfur component derived from heavy oil by burner combustion using heavy oil. Further, the exhaust gas G1 contains a sulfur component, a fluorine component, a chlorine component and the like derived from the fining agent. Further, the exhaust gas G1 contains a boron component that easily volatilizes from the molten glass when borosilicate glass is produced. The sulfur component in the exhaust gas G1 is mainly sulfur oxide (SO _X ), the chlorine component is mainly hydrogen chloride (HCl), the fluorine component is mainly hydrogen fluoride (HF), and the boron component is mainly boric acid (H _3). BO ₃ ).

Next, the cooling tower 20 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2.

The cooling tower 20 includes an inlet portion 21, a diameter-expanded portion 23, a cooling tower main body 25, a spray nozzle 26, a solid matter recovery means 27, and an outlet portion.

As shown in FIG. 2, the cooling tower main body 25 is provided upright in a cylindrical shape. The enlarged diameter portion 23 is provided so as to be connected to the upper portion of the cooling tower main body 25. The inlet portion 21 is provided so as to be connected to the upper portion of the enlarged diameter portion 23. The inlet portion 21 changes the flow of the exhaust gas G1 flowing into the cooling tower 20 from the horizontal direction to the vertical direction downward.

The diameter of the cross section of the enlarged diameter portion 23 gradually increases from the inlet portion 21 toward the cooling tower main body 25. The cross section of the enlarged diameter portion 23 is typically circular, but may be rectangular. The enlarged diameter portion 23 reduces the flow velocity of the exhaust gas G1 that has passed through the inlet portion 21.

The cooling tower main body 25 has a reaction space inside, and produces a reaction product by the reaction of the exhaust gas G1 that has passed through the enlarged diameter portion 23 with the cooling aqueous solution L21 and the treatment liquid L22.

The spray nozzle 26 is provided on the side surface of the enlarged diameter portion 23, and cools the exhaust gas G1 by spraying the cooling aqueous solution L21 and the treatment liquid L22 in the flow direction of the exhaust gas G1. As a result, the temperature of the exhaust gas G2 after cooling can be lowered to prevent the filter cloth in the bag filter 30, which will be described later, from being damaged by heat. Further, the exhaust gas G1 is reacted with the cooling aqueous solution L21 and the treatment liquid L22 to remove the sulfur component or the chlorine component in the exhaust gas G1.

The cooling aqueous solution L21 of the present embodiment is a sodium hydroxide (NaOH) aqueous solution, and the treatment liquid L22 is an aqueous solution containing sodium hydroxide as a main component. Sodium hydroxide is used as a general neutralizer for acidic effluent because it is inexpensive and easy to handle.

As shown in FIG. 2A, the spray nozzle 26 sprays the cooling aqueous solution L21 and the treatment liquid L22 radially from the injection port of the nozzle. The injection angle α of the spray nozzle 26 is preferably 30 to 70 °, more preferably 40 to 60 °. When the injection angle α is 30 ° or more, the cooling aqueous solution L21 and the treatment liquid L22 spread over the entire cooling tower main body 25, and the sulfur component or chlorine component in the exhaust gas G1 can be sufficiently removed. Further, when the injection angle α is 70 ° or less, it is possible to prevent a large amount of the reaction products of the cooling aqueous solution L21, the treatment liquid L22 and the exhaust gas G1 from adhering to the wall surface of the cooling tower main body 25. If a large amount of the reactant adheres to the wall surface, it causes the cooling tower body 25 to be blocked.

As shown in FIG. 2B, a plurality of spray nozzles 26 are provided, and each of them is installed on a concentric circle with the center of the enlarged diameter portion 23 at intervals in the circumferential direction.

In the present embodiment, the number of spray nozzles 26 is 9, but the present invention is not limited to this, and 2 to 20 spray nozzles are preferable, and 2 to 15 spray nozzles are more preferable. When the number of the spray nozzles 26 is two or more, the cooling aqueous solution L21 and the treatment liquid L22 can be sprayed separately. Further, when the number of the spray nozzles 26 is 20 or less, the spray nozzles 26 can be installed at intervals in the circumferential direction. When the number is large, two or more rows may be installed in the radial direction on a concentric circle with the center of the enlarged diameter portion 23.

Of the nine spray nozzles 26, for example, six spray the cooling aqueous solution L21 and three spray the treatment liquid L22. Here, as will be described later, the treatment liquid L22 contains sodium tetraborate (Na ₂ B ₄ O ₇ ) or magnesium borate (Mg B ₂ O ₄ ), so that sodium tetraborate or magnesium borate does not precipitate. It is necessary to control the temperature. Therefore, it is preferable that the cooling aqueous solution L21 and the treatment liquid L22 are sprayed separately without being mixed.

The total flow rate of the spray nozzle 26 needs to be appropriately adjusted depending on the flow rate of the exhaust gas G1, but is preferably 1000 to 5000 L / h, more preferably 2000 to 4000 L / h.

In the present embodiment, the spray nozzle 26 is used to spray the cooling aqueous solution L21 and the treatment liquid L22, but the present invention is not limited to this, and the liquid can be sprayed or sprayed onto the exhaust gas G1. Any contact means may be used.

The solid matter recovery means 27 of the cooling tower 20 is provided at the bottom of the cooling tower main body 25. The solid matter recovery means 27 recovers the reaction product produced in the cooling tower main body 25 as the solid matter S2. The solid substance S2 contains sodium sulfate (Na ₂ SO ₄ ) derived from the sulfur component in the exhaust gas G1 and sodium chloride (NaCl) derived from the chlorine component in the exhaust gas G1.

The outlet portion of the cooling tower 20 is provided so as to be connected to the lower side surface of the cooling tower main body 25. The outlet portion discharges the exhaust gas G2 after cooling.

The temperature T1 of the exhaust gas G1 at the inlet portion 21 is preferably 700 to 900 ° C. When the temperature T1 is 700 ° C. or higher, the sulfur component or chlorine component in the exhaust gas G1 sufficiently reacts with the cooling aqueous solution L21 and the treatment liquid L22. Further, when the temperature T1 is 900 ° C. or lower, damage in the cooling tower 20 can be prevented.

The cooling aqueous solution L21 of the present embodiment is a sodium hydroxide (NaOH) aqueous solution, but may be a magnesium hydroxide (Mg (OH) ₂ ) aqueous solution. In this case, the treatment liquid L22 is an aqueous solution containing magnesium hydroxide as a main component. Each component in the exhaust gas G1 reacts with the cooling aqueous solution L21 and the treatment liquid L22, the sulfur component in the exhaust gas G1 becomes magnesium sulfate (Regular ₄ ), and the chlorine component in the exhaust gas G1 is magnesium chloride (MgCl ₂ ). It becomes.

Magnesium hydroxide is used as a neutralizer for general acidic wastewater because it is inexpensive and easy to handle. However, since it has low solubility in water and is usually in a slurry state, the liquid is circulated and reused. If this is the case, there is a concern that the piping may be clogged. However, since the treatment liquid L22 contains a boron component, magnesium hydroxide does not become a slurry state and can be sent out from the scrubber 50 to the cooling tower 20 without causing the problem of clogging.

The concentration C21 of the cooling aqueous solution L21 is preferably 0.3% or more, more preferably 0.5% or more. The concentration C21 is preferably 2.0% or less, more preferably 1.0% or less. When the concentration C21 is 0.3% or more, the sulfur component or the chlorine component in the exhaust gas G1 can be sufficiently removed. Further, when the concentration C21 is 2.0% or less, the spray nozzle 26 can be prevented from being blocked by the drying of the cooling aqueous solution L21, and the discharge amount of the solid matter S2 can be reduced.

The bag filter 30 in FIG. 1 includes three bag filter main bodies 31 and powder recovery means 37.

The bag filter main body 31 is provided with a filter cloth inside and is connected to the adjacent bag filter main body 31 to form a flow path through which the exhaust gas G2 passes after cooling.

The filter cloth carries a powder of an alkali metal salt or an alkaline earth metal salt, and the exhaust gas G2 after cooling is brought into contact with the powder to obtain the exhaust gas G3 after contact. The cooled exhaust gas G2 reacts with the powder, and the sulfur component, the fluorine component or the chlorine component in the cooled exhaust gas G2 is removed. Further, after cooling, soot dust in the exhaust gas G2 is collected and removed with a filter cloth.

As the material of the filter cloth, it is preferable to use a polytetrafluoroethylene (PTFE) resin. Polytetrafluoroethylene is chemically stable and is excellent in heat resistance and chemical resistance.

The bag filter main body 31 is provided with a gas nozzle above the filter cloth. The bag filter main body 31 blows compressed air onto the filter cloth using a gas nozzle to wipe off the powder carried by the filter cloth and the reaction product of the exhaust gas G2 and the powder after cooling. The gas nozzle may use a gas such as oxygen or nitrogen instead of compressed air.

The powder recovery means 37 recovers the powder and the reaction product as the powder S3. The powder collecting means 37 transports the powder S3 recovered from the bottoms of the three bag filter main bodies 31 by a conveyor or the like and collects them in one place.

Since the bag filter 30 can remove the fluorine component in the exhaust gas G2 after cooling, it is possible to prevent the fluorine component from being mixed into the scrubber 50 by the exhaust gas G3 and G4 after contact. This makes it possible to prevent the fluorine component from reacting with magnesium hydroxide to form a slurry in the scrubber 50. Specifically, it is possible to prevent the formation of poorly soluble magnesium fluoride (MgF ₂ ) in water.

The bag filter 30 of FIG. 1 includes three bag filter main bodies 31, but the present invention is not limited thereto. The number of bag filter main bodies 31 is preferably 2 to 15, more preferably 2 to 10. When the number of the bag filter main bodies 31 is 2 or more, the distance of the flow path through which the cooled exhaust gas G2 passes can be lengthened, and the sulfur component, the fluorine component or the chlorine component in the cooled exhaust gas G2 is removed with high efficiency. be able to. Further, when the number of the bag filter main bodies 31 is 15 or less, the investment cost and the operating cost of the equipment can be suppressed. The number of the bag filter main body 31 may be one.

The powder supply device 35 includes three powder supply device main bodies 36.

Powder powder supplying device body 36, a powder of an alkali metal salt or alkaline earth metal salts, is supplied to the bag filter 30 through the pipe.

The number of the powder supply device main body 36 is preferably the same as the number of the bag filter main body 31. As a result, the amount of powder supplied to the bag filter main body 31 can be adjusted independently.

The powder supply device 35 preferably supplies 1.0 to 5.0 g of powder, and more preferably 2.0 to 3.0 g of powder, to 1 Nm ³ of the cooled exhaust gas G2.

Since the amount of powder adhered to the filter cloth in the bag filter main body 31 gradually increases from the powder supply device main body 36, the pressure difference between the inlet and the outlet of the bag filter 30 increases. The pressure difference is preferably 30 to 150 mmH ₂ O. When he pressure differential 30mmH 2 _O or more, powder has sufficiently adhere to the filter cloth, it is possible to sufficiently remove the sulfur components in the cooling after the exhaust gas G2, the fluorine component or chlorine component. Further, when the pressure difference is 150 mmH ₂ O or less, the exhaust gas G2 easily flows after cooling.

The pressure difference of the bag filter 30 is preferably adjusted together with the pressure difference of each bag filter main body 31.

The alkali metal salt is preferably sodium hydrogen carbonate (NaHCO ₃ ) or sodium carbonate (Na ₂ CO ₃ ). The alkaline earth metal salt is preferably calcium hydroxide (Ca (OH) ₂ ), calcium carbonate (CaCO ₃ ), or a compound salt of calcium carbonate and magnesium carbonate (MgCO ₃ ). The double salt is, for example, dolomite.

After cooling, each component in the exhaust gas G2 reacts with the powder of the alkali metal salt or the alkaline earth metal salt. After cooling, the sulfur component in the exhaust gas G2 becomes sodium sulfate (Na ₂ SO ₄ ) or calcium sulfate (CaSO ₄ ), the fluorine component becomes sodium fluoride (NaF) or calcium fluoride (CaF ₂ ), and the chlorine component becomes sodium chloride. It becomes (NaCl) or calcium chloride (CaCl ₂ ). When a double salt such as dolomite is used as the powder of the alkaline earth metal salt, the sulfur component is magnesium sulfate (sulfonyl ₄ ), the fluorine component is magnesium fluoride (MgF ₂ ), and the chlorine component is magnesium chloride (MgCl ₂ ). Generate. The powder S3 is a mixture of these reactants.

The average particle size of the alkali metal salt or alkaline earth metal salt powder is preferably 1 to 100 μm, more preferably 1 to 50 μm, and even more preferably 1 to 30 μm. When the average particle size is 1 μm or more, the powder can be produced inexpensively by the pulverization operation. When the average particle size is 100 μm or less, the sulfur component, chlorine component, or fluorine component in the exhaust gas G2 after cooling is sufficiently reacted with the powder and removed.

Here, the average particle size is defined as the cumulative volume when the particle size is measured by a laser diffraction / scattering type particle size distribution measuring device (Microtrac FRA9220 manufactured by Nikkiso Co., Ltd.) and the cumulative volume is calculated with the total volume as 100%. It is a particle size at a point of 50%.

The powder S3 contains a calcium component and a magnesium component, and if the average particle size is 30 to 100 μm, it is suitable for reuse as a glass raw material for non-alkali glass.

The temperature T2 of the cooled exhaust gas G2 is preferably 180 to 250 ° C. at the inlet of the bag filter 30. When the temperature T2 is 180 ° C. or higher, the sulfur component, chlorine component or fluorine component in the exhaust gas G2 after cooling is sufficiently reacted with the powder and removed. Further, when the temperature T2 is 250 ° C. or lower, it is possible to prevent the filter cloth in the bag filter main body 31 from being damaged by heat.

The concentration of the sulfur component contained in the post-contact flue gas G3 is sulfur dioxide (SO ₂₎ is preferably 100 mg / Nm ³ or less in terms of, 50 mg / Nm ³ or less is more preferable. The concentration of fluorine components in contact after the exhaust gas G3 is preferably 30 mg / Nm ³ or less, more preferably ^{10mg / Nm 3, 5mg / Nm} 3 or less is more preferable. The concentration of the chlorine components in contact after the exhaust gas G3 is preferably 100 mg / Nm ³ or less, 50 mg / Nm ³ or less is more preferable.

The concentration of the sulfur component is obtained by automatic analysis by an infrared absorption method or the like, or chemical analysis. The concentration of the sulfur component is determined by, for example, IC (ion chromatograph). The concentration of the fluorine component is collected exhaust gas metering pump, is absorbed into the absorbing solution, the concentration of the fluorine component in the solution was measured by ICP, calculated from the fluorine component per exhaust 1 Nm ^3. The concentration of the chlorine component is determined by the same method as the concentration of the fluorine component.

Next, the denitration device 40 according to the embodiment of the present invention will be described with reference to FIG.

The denitration device 40 includes a catalyst layer and a gas injection nozzle. The denitration device 40 injects ammonia (NH ₃ ) gas using a gas injection nozzle after the contact and before the exhaust gas G3 passes through the catalyst layer. As a result, nitrogen oxides (NO _X ) contained in the exhaust gas G3 after contact are removed. The post-contact exhaust gas G4 that has passed through the denitration device 40 flows into the scrubber 50.

As the catalyst layer, it is preferable to use a catalyst containing vanadium pentoxide (V ₂ O ₅ ) as an active ingredient. For example, a catalyst using titanium oxide (TiO ₂ ) as a carrier (TiO _2- V ₂ O _5- WO ₃ ). Is used.

The injection amount of ammonia gas is preferably 5 to 20 Nm ³ / h. When it is 5 Nm ³ / h or more, nitrogen oxides (NO _x ) can be sufficiently decomposed. In addition, when the injection amount is 20 Nm ³ / h or less, the reaction between sulfur trioxide (SO ₃ ) and ammonia (NH ₃ ) in the exhaust gas G3 after contact is suppressed, and ammonium hydrogen sulfate (NH ₄ HSO ₄ ) is produced. Can be reduced. Ammonium hydrogen sulfate clogs the catalyst pores, so it is desirable not to generate it. For that purpose, as described above, it is also necessary to adjust the concentration of the sulfur component contained in the exhaust gas G3 after contact. Therefore, the concentration of the sulfur component in the exhaust gas G3 after contact is preferably 100 mg / Nm ³ or less in terms of sulfur dioxide (SO ₂ ).

The temperature T3 of the exhaust gas G3 after contact is preferably 200 to 300 ° C. at the inlet of the denitration device 40. When the temperature T3 is 200 ° C. or higher, the nitrogen oxides (NO _X ) in the exhaust gas G3 after contact sufficiently react with the ammonia (NH ₃ ) gas. Further, when the temperature T3 is 300 ° C. or lower, it is possible to prevent the catalytic activity from decreasing. It is preferable to provide a temperature adjusting means (for example, a burner) in the flow path between the bag filter 30 and the denitration device 40 to heat the flow path and adjust the temperature T3. This is because the temperature at the outlet of the bag filter 30 drops to 200 ° C. or lower. For example, natural gas is used as the fuel for the burner.

The post-contact exhaust gas G4 that has passed through the denitration device 40 preferably has a nitrogen oxide (NO _X ) concentration of 800 mg / Nm ³ or less, and more preferably 500 mg / Nm ³ or less. The concentration of nitrogen oxides is obtained from automatic measurement by chemiluminescence method or the like. The denitration device 40 may not be provided as long as the concentration of nitrogen oxides (NO _X ) in the exhaust gas G3 after contact is 800 mg / Nm ³ or less. In this case, the exhaust gas G3 will flow into the scrubber 50 after contact.

FIG. 3 is a schematic view of a scrubber according to an embodiment of the present invention. The scrubber 50 according to the embodiment of the present invention will be described with reference to FIGS.

The scrubber 50 includes a press club bar 510, a scrubber main body 520 provided connected to the press club bar 510, and a drainage tank 530 provided at the bottom of the scrubber main body 520.

The scrubber 50 reacts the exhaust gas G4 and G41 after contact with the cooling liquids L51 and L52 and the treatment liquid L22 to obtain a clean gas G5 and a drainage liquid L55. Water or an aqueous sodium hydroxide solution is used as the cooling liquids L51 and L52.

Further, the scrubber 50 includes an adjusting means 539 that adjusts the pH and temperature of the drainage L55 to be the treatment liquid L22, a return pipe 550 that connects the drainage tank 530 and the cooling tower 20, the drainage tank 530 and the scrubber. A return pipe 551 for connecting the main body 520 is provided.

The press clubber 510 has a structure in which exhaust gas G4 flows in from the upper part and is discharged to the lower part after contact, and a nozzle 511 is provided in the upper part. The nozzle 511 sprays the cooling liquid L51 in the flow direction of the exhaust gas G4 after contact. By adjusting the flow rate of the cooling liquid L51, the temperature of the exhaust gas G41 after contact can be appropriately adjusted. The cooling liquid L51 after contacting with the exhaust gas G4 after contact is recovered as drainage L55 in the drainage tank 530.

In FIG. 3, the number of nozzles 511 is one, but a plurality of nozzles may be provided. Further, the nozzle may be provided in the lower part of the press clubber 510 and spray the cooling liquid L51 in a direction opposite to the flow of the exhaust gas G4 after contact.

Further, although not shown in FIG. 3, the press clubr 510 may be further provided with a nozzle to spray the treatment liquid L22.

Further, the press clubr 510 may be provided with a drainage tank at the bottom. In this case, the drainage tank collects the cooling liquid L51 after contacting with the exhaust gas G4 after contact as drainage.

Scrubber body 520 flows the post-contact gas G41 discharged from flop Les scrubber 510 from the bottom, is discharged to the top. The scrubber body 520 includes a filling layer 521 inside, and nozzles 523 and 525 above the filling layer 521. The nozzle 523 is provided between the filling layer 521 and the nozzle 525.

The nozzle 523 is connected to the return pipe 551 and sprays the treatment liquid L22 in a direction opposite to the flow of the exhaust gas G41 after contact. The nozzle 525 sprays the cooling liquid L52 in a direction opposite to the flow of the exhaust gas G41 after contact.

The scrubber body 520 brings the cooling liquid L52 and the treatment liquid L22 into contact with the post-contact exhaust gas G41 to dissolve the boron component in the post-contact exhaust gas G41 in the cooling liquid L52 and the treatment liquid L22. At this time, components other than the boron component in the contact exhaust gas G41 may be dissolved in the cooling liquid L52 and the treatment liquid L22. For example, after contact, the sulfur component or chlorine component in the exhaust gas G41 dissolves. By adjusting the flow rates of the cooling liquid L52 and the treatment liquid L22, the temperature of the exhaust gas G41 after contact can be appropriately adjusted. The cooling liquid L52 after contacting with the exhaust gas G41 after contact is recovered as drainage L55 in the drainage tank 530.

The packing layer 521 creates a pressure difference between the upper part and the lower part of the scrubber body 520. As a result, the exhaust gas G41 after contact becomes a turbulent state in the scrubber body 520, the exhaust gas G41 after contact and the cooling liquid L52 and the treatment liquid L22 are sufficiently contacted, and the cooling liquid L52 of the components in the exhaust gas G41 after contact , Dissolution in the treatment liquid L22 can be promoted. The pressure difference between the inlet and outlet of the scrubber 50 is preferably 50 to 200 mmH ₂ O.

The packed bed 521 floats a plastic ball as a filling and promotes the reaction by a water film on the surface of the ball. The filler of the packing layer 521 is preferably one having a large surface area, easy formation of a water film, low resistance to gas flow, low overflow or drift, or light and durable. The material of the filler of the packing layer 521 is preferably polypropylene. Polypropylene is superior in that it is lightweight and inexpensive. The diameter of the particles constituting the packing is preferably 40 to 100 mm.

It is preferable to use fiber reinforced plastic (FRP) having excellent corrosion resistance in the press clubber 510 and the scrubber body 520.

When the cooling aqueous solution L21 used in the cooling tower 20 is a magnesium hydroxide aqueous solution, water or a magnesium hydroxide aqueous solution is used as the cooling liquids L51 and L52. In this case, a magnesium hydroxide aqueous solution is used as the pH adjusting aqueous solution L54 described later.

Here, when the cooling liquids L51 and L52 contain a Ca component as a neutralizing agent, precipitates such as calcium sulfate (CaSO ₄ ) and calcium borate (CaB ₄ O ₇ ) are formed in the drainage tank 530. Will be generated. Such deposits can block the return pipes 550,551. Therefore, it is desirable that the cooling liquids L51 and L52 do not contain a Ca component as a neutralizing agent.

The drainage tank 530 accommodates the drainage L55. The boron component in the exhaust gas G4 and G41 after contact is dissolved in the drainage L55. It is preferable to use fiber reinforced plastic (FRP) having excellent corrosion resistance in the drainage tank 530.

The drainage tank 530 also includes a pH measuring meter 533, a thermometer, a cooling nozzle, and a heater. The cooling nozzle injects the cooling water L53 into the drainage tank 530.

The adjusting means 539 includes an injection tank 540, a circulation pump 541, and an injection nozzle. The injection tank 540 stores the pH adjusting aqueous solution L54. The injection nozzle injects the pH adjusting aqueous solution L54 from the injection tank 540 into the drainage tank 530 via the circulation pump 541. As the pH adjusting aqueous solution L54, a sodium hydroxide aqueous solution is used.

The concentration C54 of the pH adjusting aqueous solution L54 is preferably 20% or more, more preferably 30% or more. When the concentration C54 is 20% or more, it is suitable for adjusting the pH of the drainage L55.

Further, the adjusting means 539 adjusts the drainage L55 to a pH of 5 to 9 and a temperature of 40 ° C. or higher. As a result, a treatment liquid L22 containing a boron component and a sodium component or a magnesium component is produced. In the process of preparing the treatment liquid L22, the boron component in the waste liquid L55 reacts with sodium hydroxide or magnesium hydroxide, and sodium tetraborate (Na ₂ B ₄ O ₇ ) or magnesium borate (Mg B ₂ O). ₄ ) is generated. The treatment liquid L22 may contain an unreacted boron component, sodium hydroxide or magnesium hydroxide. Further, the treatment liquid L22 may contain a small amount of chlorine, fluorine, calcium and the like.

The return pipe 550 sends the processing liquid L22 from the drainage tank 530 to the spray nozzle 26 of the cooling tower 20 via the circulation pump 531.

The return pipe 551 sends the processing liquid L22 from the drainage tank 530 to the nozzle 523 of the scrubber main body 520 via the circulation pump 531.

It is preferable that the return pipes 550 and 551 are provided with a heater for adjusting the temperature of the treatment liquid L22.

The amount of sodium hydroxide or magnesium hydroxide injected into the drainage tank 530 is preferably an amount sufficient to convert the boron component, sulfur component or chlorine component in the drainage L55 into a sodium salt or magnesium salt. .. However, if the amount of sodium hydroxide supplied is too large, sodium tetraborate or magnesium borate is saturated and precipitated. When sodium tetraborate or magnesium borate precipitates, the return pipes 550 and 551 are blocked, so that it becomes difficult to send the treatment liquid L22 to the spray nozzle 26 of the cooling tower 20 or the nozzle 523 of the scrubber body 520.

Therefore, the pH of the treatment liquid L22 in the drainage tank 530 is measured with a pH measuring meter 533, and the pH is kept in the range of 5 to 9. At this time, the pH and temperature are adjusted by adjusting the supply amounts of the cooling water L53 and the pH adjusting aqueous solution L54.

The pH of the treatment liquid L22 is preferably 6 to 8, more preferably 6.5 to 7.5. When he pH of 5 or more of the processing liquid L22, can be converted to such boron component in the treating solution L22 to satisfactorily sodium or Ma grayed Neshiumu salt, less boron component such unreacted remaining in the treatment liquid L22 can do. Further, when the pH of the treatment liquid L22 is 9 or less, it is possible to prevent the precipitation of sodium tetraborate or magnesium borate in the treatment liquid L22.

The temperature T22 of the treatment liquid L22 is adjusted so as to be maintained at 40 ° C. or higher. The temperature T22 is preferably 50 ° C. or higher, more preferably 60 ° C. or higher. The temperature T22 is preferably 90 ° C. or lower, more preferably 80 ° C. or lower. By setting the temperature T22 to 40 ° C. or higher, it is possible to prevent the precipitation of sodium tetraborate or magnesium tetraborate in the treatment liquid L22. Further, when the temperature is 90 ° C. or lower, damage due to heat in the drainage tank 530 can be prevented.

The drainage tank 530 of the present embodiment is provided at the bottom of the scrubber main body 520, but may be provided at a place different from the scrubber main body 520 via a pipe. This embodiment, when collecting the drainage at the bottom of the flop les scrubber 510, are excellent in that the drainage flop les scrubber 510 and scrubber body 520 can be aggregated and processed at one location.

The temperature T4 of the exhaust gas G4 after contact is preferably 200 to 300 ° C. at the inlet of the scrubber 50. When the temperature T4 is 200 ° C. or higher, the boron component in the exhaust gas G4 and G41 after contact can be sufficiently removed. Further, when the temperature T4 is 300 ° C. or lower, damage to the packed bed 521 due to heat can be prevented.

The temperature of the exhaust gas G41 after contact is preferably 60 to 90 ° C, more preferably 70 to 80 ° C. When the temperature of the exhaust gas G41 after contact is 60 ° C. or higher, the amount of cooling liquids L51 and L52 used can be reduced. Further, when the temperature of the post-contact exhaust gas G41 is 90 ° C. or lower, the boron component in the post-contact exhaust gas G41 can be dissolved in the cooling liquid L52 and the treatment liquid L22 and separated.

The concentration of boron component in the clean gas G5 is boron oxide _(B 2 _{O 3)} is preferably 20 mg / Nm ³ or less in terms of, 10 mg / Nm ³ or less is more preferable.

Next, the main fan 60 and the chimney 70 according to the embodiment of the present invention will be described.

The clean gas G5 is sucked by the main fan 60 that adjusts the flow rate of the exhaust gas, and the clean gas G6 that has passed through the main fan 60 is released to the atmosphere as the clean gas G7 through the chimney 70.

The temperature of the clean gas G5 is 60 to 90 ° C. immediately after passing through the scrubber 50. The clean gas G5 may be sucked by the main fan 60 without adjusting the temperature as it is, but if the temperature is low, the chimney effect of the chimney 70 becomes small. Therefore, it is preferable to provide a burner in the flow path between the scrubber 50 and the main fan 60 for heating, and the temperature T5 of the clean gas G5 before flowing into the main fan 60 is preferably 100 to 130 ° C.

According to the exhaust gas treatment device 1 of the present embodiment, the clean gas G7 has a sulfur component concentration of 100 mg / Nm ³ or less in terms of sulfur dioxide (SO ₂ ) and a nitrogen oxide (NO _X ) concentration of 800 mg / Nm ^3. Hereinafter, the concentration of the fluorine component can be achieved to be 30 mg / Nm ³ or less, the concentration of the chlorine component to be 100 mg / Nm ³ or less, and the concentration of the boron component to be 20 mg / Nm ³ or less in terms of boron oxide (B ₂ O ₃ ). The exhaust gas treatment device 1 is suitable for exhaust gas treatment in which the flow rate of the clean gas G7 is 5,000 to 40,000 Nm ³ / h.

[Exhaust gas treatment method]
FIG. 4 is a flowchart showing an exhaust gas treatment method according to an embodiment of the present invention. The exhaust gas treatment method according to the embodiment of the present invention will be described with reference to FIG.

The exhaust gas treatment method of the present embodiment includes a glass melting step ST1 for melting a glass raw material, a cooling step ST2 for obtaining a cooling exhaust gas by bringing a cooling aqueous solution into contact with the exhaust gas generated in the glass melting step ST1, and a cooling exhaust gas. The present invention comprises a powder recovery step ST3 in which a powder of an alkali metal salt or an alkaline earth metal salt is brought into contact with each other to obtain an exhaust gas after contact, and a reaction product of the exhaust gas after cooling and the powder is recovered as a powder. Further, the exhaust gas treatment method includes a denitration step ST4 for removing nitrogen oxides contained in the exhaust gas after contact, and the exhaust gas after contact and the cooling liquid while obtaining a clean gas by contacting the cooling liquid with the exhaust gas after contact. The exhaust gas treatment step ST5 for collecting the reaction solution as an exhaust gas is provided.

In the effluent treatment step ST5, the effluent is adjusted to pH 5-9 and the temperature is 40 ° C. or higher to prepare a effluent, and the effluent is sent back to the cooling step. In the cooling step ST2, the treatment liquid is brought into contact with the exhaust gas.

In the cooling step ST2, the cooling aqueous solution is preferably a sodium hydroxide aqueous solution or a magnesium hydroxide aqueous solution. Further, in the cooling step ST2, it is preferable that a reaction product is generated by the reaction between the exhaust gas and the cooling aqueous solution, and the reaction product is recovered as a solid product.

In the powder recovery step ST3, the alkali metal salt is preferably sodium hydrogen carbonate or sodium carbonate. The alkaline earth metal salt is preferably calcium hydroxide, calcium carbonate, or a double salt of calcium carbonate and magnesium carbonate.

In the denitration step ST4, it is preferable to inject ammonia gas after the contact and before the exhaust gas passes through the catalyst layer.

As described above, according to the exhaust gas treatment method and the exhaust gas treatment device 1 of the present embodiment, sulfur components, boron components and the like in the exhaust gas can be sufficiently removed without using complicated wet equipment. Therefore, the investment cost of the wet equipment (scrubber 50) can be suppressed. Further, according to the exhaust gas treatment device 1 of the present embodiment, since the treatment liquid L22 obtained by the scrubber 50 is reused in the cooling tower 20, the amount of the cooling aqueous solution L21 used in the cooling tower 20 is reduced, and the operating cost is reduced. Can be suppressed.

[Manufacturing equipment and manufacturing method for glass articles]
Next, a manufacturing apparatus and a manufacturing method for glass articles using the exhaust gas treatment apparatus of the present embodiment will be described.

The glass raw material is supplied into the glass melting furnace, and the flame of the burner is radiated toward the glass raw material to heat and melt the glass raw material. The glass raw material may be heated by heating with the flame of a burner and energizing by applying a voltage to a plurality of energizing electrodes.

The molten glass obtained by melting the glass raw material is molded in a molding furnace provided on the downstream side of the glass melting furnace. The molded glass is slowly cooled in a slow cooling furnace provided on the downstream side of the molding furnace to become a glass article.

To obtain a glass plate as a glass article, for example, a float method is used. The float method is a method in which molten glass introduced onto a molten metal (for example, molten tin) housed in a float bath is used as a strip-shaped glass ribbon. The glass ribbon is pulled up from the molten metal and slowly cooled while being conveyed in the slow cooling furnace to become flat glass. After being carried out from the slow cooling furnace, the plate glass is cut into a predetermined size and shape by a cutting machine to become a product glass plate.

Further, a fusion method may be used as another molding method for obtaining the glass plate. In the fusion method, the molten glass that overflows from the upper edges on both the left and right sides of the gutter-shaped member is allowed to flow down along the left and right side surfaces of the gutter-shaped member, and is combined at the lower edges where the left and right side surfaces intersect to form a strip. This is a method of using a glass ribbon. The molten glass ribbon is slowly cooled while moving downward in the vertical direction to become flat glass. The flat glass is cut into a predetermined size and shape by a cutting machine to become a product glass plate.

The method for producing a glass article of the present embodiment is not particularly limited in the composition of the glass raw material, but is preferably used for the method for producing boron-containing borosilicate glass. In addition, the method for producing a glass article of the present embodiment is suitable for producing a glass raw material composition containing a fluorine component and a chlorine component as a clarifying agent, particularly an alkali-free composition of aluminoborosilicate glass. Alkali-free composition aluminoborosilicate glass is suitable for liquid crystal displays (LCD) and organic light emitting diodes (OLED) applications.

The glass article of the present embodiment has a non-alkali glass composition, and as a preferable example from the viewpoint of increasing strain points and solubility, in terms of oxide-based mass percentage display, SiO ₂ : 58 to 66%, Al ₂ O ₃ : 15 to 22%, B ₂ O ₃ : 5 to 12%, MgO: 0.5 to 8%, CaO: 0.5 to 9%, SrO: 3 to 12.5%, BaO: 0 to 2%, Cl : 0.01 to 0.35%, F: 0.01 to 0.15%, and SO ₃ : 0.0001 to 0.0025%, MgO + CaO + SrO + BaO: 9 to 18%, MgO / (MgO + CaO): 0 .35 to 0.55.

As a particularly preferable example from the viewpoint of increasing solubility, in terms of mass percentage display based on oxides, SiO ₂ : 50 to 61.5%, Al ₂ O ₃ : 10.5 to 18%, B ₂ O ₃ : 7 to 10%, MgO: 2-5%, CaO: 0.5-14.5%, SrO: 0-24%, BaO: 0-13.5%, Cl: 0.01-0.35%, F: It contains 0.01 to 0.15% and SO ₃ : 0.0001 to 0.0025%, MgO + CaO + SrO + BaO: 16 to 29.5%, MgO / (MgO + CaO): 0.3 to 0.5.

As a particularly preferable example from the viewpoint of increasing the strain point, in the mass percentage display based on the oxide, SiO ₂ : 54 to 73%, Al ₂ O ₃ : 10.5 to 22.5%, B ₂ O ₃ : 0. 1-12%, preferably 0.3-12%, more preferably 0.5-5.5%, MgO: 0.5-10%, CaO: 0.5-9%, SrO: 0-16% , BaO: 0-2.5%, Cl: 0.01-0.35%, F: 0.01-0.15%, and SO ₃ : 0.0001-0.0025%, MgO + CaO + SrO + BaO: 8 ~ 26%, MgO / (MgO + CaO): 0.3 to 0.8.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

1 Exhaust gas treatment device 10 Glass melting furnace 20 Cooling tower 21 Inlet part 23 Diameter expansion part 25 Cooling tower body 26 Spray nozzle 27 Solid matter recovery means 30 Bug filter 31 Bug filter body 35 Powder supply device 36 Powder supply device body 37 Powder recovery Means 40 Denitration device 50 Scrubber 510 Press clubber 511 Nozzle 520 Scrubber body 523,525 Nozzle 530 Drainage tank 531 Circulation pump 533 pH meter 539 Adjusting means 540 Injection tank 541 Pump 550,551 Return pipe 60 Main fan 70 Chimney L21 For cooling Aqueous solution L22 Treatment liquid L51, L52 Cooling liquid L53 Cooling water L54 pH adjusting aqueous solution L55 Exhaust liquid G1 Exhaust gas G2 Cooling exhaust gas G3, G4, G41 Contact exhaust gas G5 to G7 Clean gas S2 Solid S3 Powder ST1 Glass melting step ST2 Cooling process ST3 Powder recovery process ST4 Denitration process ST5 Drainage treatment process

Claims (10)

The glass melting process that melts the glass raw material and
A cooling step in which an aqueous solution for cooling is brought into contact with the exhaust gas generated in the glass melting step to obtain exhaust gas after cooling.
A powder recovery step in which a powder of an alkali metal salt or an alkaline earth metal salt is brought into contact with the cooled exhaust gas to obtain a contacted exhaust gas, and a reaction product of the cooled exhaust gas and the powder is recovered as a powder.
A drainage treatment step of recovering the reaction liquid of the post-contact exhaust gas and the cooling liquid as a drainage liquid while contacting the cooling liquid with the post-contact exhaust gas to obtain a clean gas is provided.
In the effluent treatment step, a effluent is prepared by adjusting the effluent to pH 5-9 and a temperature of 40 ° C. or higher, and the effluent is sent back to the cooling step.
The cooling step is an exhaust gas treatment method characterized in that the treatment liquid is brought into contact with the exhaust gas, a reaction product is generated by the reaction between the exhaust gas and the cooling aqueous solution, and the reaction product is recovered as a solid substance . The exhaust gas treatment method according to claim 1, wherein the cooling aqueous solution is a sodium hydroxide aqueous solution or a magnesium hydroxide aqueous solution. The exhaust gas treatment method according to claim 1 or 2, wherein the alkali metal salt is sodium hydrogen carbonate or sodium carbonate. The exhaust gas treatment method according to claim 1 or 2, wherein the alkaline earth metal salt is calcium hydroxide, calcium carbonate, or a double salt of calcium carbonate and magnesium carbonate. Between the powder recovery step and the effluent treatment step, there is a denitration step of removing nitrogen oxides contained in the exhaust gas after the contact.
The exhaust gas treatment method according to any one of claims 1 to 4 , wherein the denitration step injects ammonia gas after the contact before the exhaust gas passes through the catalyst layer. An exhaust gas treatment device including a glass melting furnace that generates exhaust gas, a cooling tower, a bag filter, and a scrubber.
The cooling tower includes a nozzle for spraying a cooling aqueous solution on the exhaust gas to obtain the exhaust gas after cooling.
The bag filter includes a filter cloth and a powder recovery means.
The filter cloth carries a powder of an alkali metal salt or an alkaline earth metal salt, and the cooled exhaust gas is brought into contact with the powder to obtain a contact exhaust gas.
The powder recovery means recovers the reaction product of the exhaust gas after cooling and the powder as a powder.
The scrubber has a nozzle for spraying a cooling liquid on the exhaust gas after contact to obtain a clean gas and a drainage liquid, an adjusting means for adjusting the pH and temperature of the drainage liquid to be a treatment liquid, and the cooling tower. Equipped with a return pipe for sending out the processing liquid,
The cooling tower includes a nozzle for spraying the treatment liquid on the exhaust gas .
The cooling tower is an exhaust gas treatment device characterized in that a solid material recovery means for recovering a reaction product generated in the cooling tower body as a solid material is provided at the bottom of the cooling tower body . The scrubber includes a press clubber and a scrubber body provided connected to the press clubber.
The exhaust gas treatment device according to claim 6 , wherein the scrubber body includes a filling layer inside. Annealing the exhaust gas treatment apparatus according to claim 6 or 7, provided on the downstream side of said glass melting furnace, a forming furnace for forming a molten glass, is provided downstream from the forming furnace, a formed glass A slow cooling furnace, and a glass article manufacturing apparatus. A method for manufacturing a glass article using the glass article manufacturing apparatus according to claim 8 . The method for producing a glass article according to claim 9 , wherein the glass article is borosilicate glass.