KR20100100854A - Process for producing boron-containing glass product and method for purifying waste gas generated in production of boron-containing glass product - Google Patents

Abstract

This invention provides the manufacturing method of the boron containing glass article provided with the process which can remove sulfur and boron simultaneously from exhaust gas, even if it contains sulfur in high concentration in exhaust gas. The present invention provides a cooling step of cooling exhaust gas containing sulfur and boron generated from a glass melting furnace by cooling means in contact with a cooling liquid to obtain a cooling discharge liquid containing sulfur and boron and exhaust gas after cooling; And a removing step of contacting the exhaust gas after the cooling with the contact liquid by a contact means to remove sulfur and boron from the exhaust gas after the cooling, and to obtain a post-contact exhaust liquid and clean gas containing sulfur and boron. It is related with the manufacturing method of the boron containing glass article with which it is equipped.

Description

PROCESS FOR PRODUCING BORON-CONTAINING GLASS PRODUCT AND METHOD FOR PURIFYING WASTE GAS GENERATED IN PRODUCTION OF BORON-CONTAINING GLASS PRODUCT}

The present invention relates to a method for producing a boron-containing glass article and a method for purifying exhaust gas generated in the production of a boron-containing glass article.

The glass product is supplied with a glass raw material and glass cullets to a glass melting furnace, heated by a burner flame in which liquid fuel such as heavy oil or kerosene or gaseous fuel such as LPG is combusted to form a molten glass, followed by a float method or the like. It is obtained by molding. Here, from the glass melting furnace, the exhaust gas containing the vaporizing substance, such as a sulfur compound and a boron compound, contained in a glass raw material, and the combustion exhaust gas containing the component in a liquid fuel or a gaseous fuel is generated. In particular, when a defoaming agent containing a sulfur compound is used or when producing a boron-containing glass product represented by an alkali free glass or a borosilicate glass, sulfur and boron are contained in the exhaust gas at a relatively high concentration. In the case of burning a fuel containing sulfur such as heavy oil in the glass melting furnace, the sulfur concentration in the exhaust gas is similarly high.

If such exhaust gas containing sulfur and boron is released into the atmosphere as it is, it may adversely affect the environment. In addition to sulfur and boron, there are fluorine, chlorine, and the like that affect the environment.

Several methods and facilities for removing such substances from exhaust gas have been proposed in the past.

For example, Patent Document 1 uses a fuel that is substantially free of sulfur as the fuel of the burner flame on one side to heat the glass raw material to obtain a molten glass, and the gas contained in the exhaust gas discharged from the glass melting furnace on the other side. A useful component that can be used as a glass raw material by collecting the phase useful component and the particulate useful component by contacting with water to form a collection liquid, neutralizing the collection liquid to form a neutralized collection liquid, and then separating the neutralized collection liquid into a solid solution. Arsenic, arsenic compounds, boron, boron compounds, chlorine or chlorine compounds) are described.

Patent Document 2 discloses a method of cooling boron-containing exhaust gas to 55 ° C. or lower to precipitate and recover boric acid from exhaust gas, wherein the boric acid precipitated and collected in the recovery device is heated to 120 to 180 ° C. A method for recovering boric acid from an exhaust gas is disclosed, wherein the boric acid is recovered from the exhaust gas by maintaining the temperature at least for 1 hour or longer.

In Patent Document 3, air is mixed into a waste gas containing boric acid to lower the absolute temperature of the waste gas, and the mixed gas is cooled to a temperature of about 40 ° C. by a heat exchanger to crystallize the boric acid gas in the mixed gas. A method for treating a waste gas comprising boric acid, characterized in that the boric acid particles produced by crystallization are collected by a dust collector, and the remaining gas portion is heated to a temperature of about 100 ° C. by the waste gas and then released into the atmosphere. .

Patent document 4 uses the water spray type cooling means which sprays water to exhaust gas, and the air mixing type cooling means which mixes air with the said exhaust gas, and cools the said exhaust gas, and uses the gas phase at the temperature exceeding 70 degreeC. The said gaseous boric acid is made by mixing the said air with the said exhaust gas containing boric acid and arsenic oxide, and cooling the exhaust gas after mixing to 70 degrees C or less, and making the moisture content in the exhaust gas after mixing into 15 volume% or less. A specific component recovery method in an exhaust gas is described, which precipitates the streams and arsenic oxides as solids and recovers the boric acid and arsenic oxides from the exhaust gas in a dry state.

Patent Document 5 discloses that the exhaust gas is cooled to a temperature near the dew point of the acid contained in the exhaust gas by indirect cooling, and then cooled to a temperature near the water dew point by introduction of secondary air. The dust collection method characterized by introducing and dust-collecting is described.

Japanese Patent Laid-Open No. 2004-238236 Japanese Patent Laid-Open No. 3-131515 Japanese Patent Laid-Open No. 61-287416 Japanese Registered Utility Model No. 3089266 Japanese Patent Laid-Open No. 2-152512

However, the method of patent document 1 is not applicable to what contains sulfur in glass raw material or the fuel of a burner flame.

In addition, the method of patent documents 2-4 is the same, and the case where sulfur is contained in exhaust gas is not applicable. In the methods described in Patent Documents 2 and 3, boric acid is precipitated by cooling the temperature of the exhaust gas to a temperature of about 40 to 55 ° C, and sulfuric acid is generated to corrode the equipment. In each facility described in Patent Documents 2 and 3, the recovery device and the heat exchanger are affected. Also in the method of patent document 4, when sulfur is contained 1 ppm or more, an acid dew point raises (specifically, 105-120 degreeC), it condenses before cooling the temperature of exhaust gas to about 70 degrees C or less, and boric acid melt | dissolves in it, Recovery to the solid aimed for by patent document 4 becomes inadequate.

In addition, in the method described in Patent Literature 5, when sulfur is contained in 1 ppm or more, the acid dew point rises, and dilution by introduction of secondary air requires an amount equivalent to that of the exhaust gas, which makes it difficult to develop into a large installation. In addition, when a lot of moisture is contained in exhaust gas (for example, in the case of a glass furnace of an oxygen combustion type), even if dilution, there is no difference between a water dew point and an acid dew point, and acid, such as boric acid, becomes a slurry without solidifying It is difficult to apply because it attaches to the inner wall and closes the duct.

Moreover, in the method described in patent document 2 and patent document 3, the process of reheating the boric acid which precipitated and deposited respectively after cooling of exhaust gas, and the process of heating the gas remaining after precipitation are unpreferable.

Therefore, an object of the present invention is to remove the sulfur and boron from the exhaust gas at the same time even when the exhaust gas contains a high concentration of sulfur, and to apply the process that can be applied even when a large amount of moisture is contained in the exhaust gas. It is providing the manufacturing method for obtaining the boron containing glass product provided. It is also an object of the present invention to produce a boron-containing glass product in which sulfur and boron are simultaneously removed from the exhaust gas when sulfur is contained at a high concentration and boron is also contained at a high concentration. Is to provide. Moreover, the objective of this invention is providing the method which does not require the heating of the boric acid or exhaust gas which precipitates in the said manufacturing method and purification method.

In the present invention, since the cooling of the conventional exhaust gas is lowered to 70 ° C. or lower, and most of it is lowered to 55 ° C. or lower, it is not necessary to deposit much of boron in the exhaust gas. It is mainly (1) and (2) shown next, characterized by the fact that boron in exhaust gas can be almost isolate | separated even if it is more than degreeC, and heating of precipitated boric acid or exhaust gas is not necessarily required.

(1) The exhaust gas containing sulfur and boron generated from the glass melting furnace is cooled by a cooling means in contact with the cooling liquid, and the exhaust gas after cooling (hereinafter referred to as "cooling exhaust gas"), and sulfur and boron A cooling step of obtaining a cooling discharge liquid comprising a contact with the after-cooling exhaust gas and a contacting liquid by contact means to remove sulfur and boron from the exhaust gas after cooling, and a clean gas and sulfur and boron A process for producing a boron-containing glass article, comprising a removing step of obtaining a discharged liquid after contact.

(2) cooling wastewater containing sulfur and boron by cooling the exhaust gas containing sulfur and boron generated from the glass melting furnace to a temperature where at least a portion of boron precipitates as a solid by cooling means for contacting with the cooling water; And a cooling step of obtaining exhaust gas after cooling, and contacting water after the cooling exhaust gas with contact water to remove sulfur and boron from the exhaust gas after cooling, and contact drainage comprising sulfur and boron, And a removal step of obtaining a clean gas, wherein the sulfur and boron are removed from the exhaust gas generated from the glass melting furnace.

According to the present invention, even when sulfur is contained at a high concentration in the exhaust gas, it is possible to provide a method for producing a boron-containing glass article having a step capable of simultaneously removing sulfur and boron from the exhaust gas. The manufacturing method of such a boron containing glass article is applicable also when a lot of moisture is contained in exhaust gas. Further, according to the present invention, in the case where sulfur is contained in a high concentration in the exhaust gas and boron is also contained in a high concentration, boron which simultaneously removes sulfur and boron, preferably sulfur, boron, fluorine and chlorine from the exhaust gas. It is possible to provide a method for purifying exhaust gas for producing a containing glass article. Moreover, according to this invention, in the said manufacturing method and purification method, the method which does not necessarily require heating of the boric acid or exhaust gas which precipitates can be provided.

1 is a schematic diagram of a manufacturing method of the present invention.
2 is a view for explaining the relationship between the pressure loss and the removal efficiency of B ₂ O ₃ by the production method of the present invention.
3 is a view for explaining the relationship between the temperature of exhaust gas after cooling by the production method of the present invention and the removal efficiency of B ₂ O ₃ .

The present invention will be described.

The present invention provides a cooling step in which an exhaust gas containing sulfur and boron generated from a glass melting furnace is cooled by a cooling means in contact with a cooling liquid to obtain an exhaust gas after cooling and a cooling discharge liquid containing sulfur and boron. And the contacting liquid is brought into contact with the after-cooling exhaust gas by means of a contact means to remove sulfur and boron from the after-cooling exhaust gas and to obtain a clean gas and a post-contact exhaust liquid containing sulfur and boron. It is a manufacturing method of a boron containing glass article provided with a process.

The manufacturing method of such a boron containing glass article is also called "the manufacturing method of this invention" below.

In addition, although this invention is also a purification method of the exhaust gas produced at the time of manufacture of a boron containing glass product, since it is the purification method provided with the cooling process and the removal process in the manufacturing method of this invention, only the manufacturing method of this invention is only below. Explain.

<Cooling process>

The cooling process of the manufacturing method of this invention is demonstrated.

In a cooling process, the exhaust gas containing sulfur and boron which generate | occur | produced from the glass melting furnace is cooled by the cooling means which contacts a cooling liquid.

<Exhaust gas>

The exhaust gas will be described.

In the production method of the present invention, a defoaming agent containing sulfur is used or a fuel containing sulfur such as heavy oil is burned in a glass melting furnace. It is also assumed that a glass (boron-containing glass) product containing substantially boron is produced. Thus, the exhaust gas contains sulfur and boron. In the exhaust gas, sulfur is usually present in the form of an oxide (SO _X ), and boron is usually present in the form of boric acid. Although boric acid in exhaust gas differs in the combustion system of a melting furnace, it is based on the boron or a boron compound which 15-25 mass% of boron in a glass raw material vaporized.

The sulfur concentration in the exhaust gas is not limited. For example, when a sulfur-containing defoamer is used so as to contain 0.1% by mass or more of sulfur in the glass raw material, or a fuel containing sulfur such as heavy oil in the melting furnace is burned. What is necessary is just the sulfur concentration in the case. For example, 10 ppm or more may be sufficient as the sulfur concentration of the said exhaust gas, and 30 ppm or more may be sufficient as it.

In addition, the sulfur concentration in the said exhaust gas shall mean the density | concentration immediately before providing to the cooling means mentioned later. The same applies to the other components (boron, fluorine, chlorine, etc.) and the temperature in the exhaust gas. The density | concentration of each component shall mean the value at the time of measuring using ICP analysis method, JISK0105 (1998), and JIS K0107 (2002). Temperature shall mean the value when it measures using the thermocouple.

The same applies to the boron concentration in the exhaust gas, and is not particularly limited, and the boron concentration in the case of producing a boron-containing glass represented by an alkali free glass or borosilicate glass may be used. The boron concentration in an alkali free glass or borosilicate glass should just be 5-15 mass%, just 5-10 mass%, and should be 7-9 mass%. Even when the boron concentration in the boron-containing glass is about 15% by mass, it is preferable that the concentration of boric acid (B ₂ O ₃ ) is preferably 10 mg / Nm 3 or less, by making the treatment conditions, such as a cooling process and a removal process, etc. preferable. More preferably, it can be 5 mg / Nm <3> or less, More preferably, it may be 1 mg / Nm <3> or less. In addition, 1Nm <3> (normal cubic meter) shows the gas volume of 1m <3> in the case of converting the target gas into a standard state (0 degreeC, 760 mmHg). Moreover, even when the boron concentration in boron containing glass is about 15 mass%, the ratio of the boron concentration (mass%) of the said clean gas with respect to the boron concentration (mass%) of the said exhaust gas becomes like this. Preferably it is 0.2 or less, More preferably, it can be 0.1 or less, More preferably, you may be 0.05 or less.

The exhaust gas may further contain fluorine. This content rate may be 2.5 mg / Nm 3 or more, 10 mg / Nm 3 or more, and 40 mg / Nm 3 or more.

In addition, chlorine may be further included. This content rate may be 8 mg / Nm <3> or more, 30 mg / Nm <3> or more, and 50 mg / Nm <3> or more may be sufficient.

Even when the exhaust gas contains fluorine and chlorine in addition to sulfur and boron, according to the glass production method of the present invention, a clean gas in which sulfur, boron, fluorine and chlorine is reduced can be obtained.

In addition, in this invention, containing sulfur, boron, fluorine, or chlorine includes not only the case where each single substance is contained but the case which contains the compound containing each single substance.

The other components of the exhaust gas are not particularly limited. In the glass manufacturing method for obtaining the boron containing glass represented by alkali free glass and borosilicate glass, what is necessary is just a component contained in the exhaust gas discharged from a melting furnace normally.

The temperature of the exhaust gas (the temperature of the exhaust gas just before providing it to the cooling means) is not particularly limited. For example, what is necessary is just the temperature which discharges from a melting furnace in the normal glass manufacturing method, cools in the process which flows through piping, etc., and passes through a bag filter. It is preferable that the said exhaust gas temperature is 130-160 degreeC, It is more preferable that it is 135-155 degreeC, It is still more preferable that it is 145-150 degreeC.

Cooling liquid

The cooling liquid will be described.

The cooling liquid comes into contact with the exhaust gas by cooling means described later, and the exhaust gas is cooled.

The kind of cooling liquid is not specifically limited, What is necessary is just to be able to cool the said exhaust gas by contacting with the said exhaust gas. For example, water (including those which have water, such as industrial water and distilled water as a main component), and seawater are mentioned. Among these, the cooling liquid is preferably water (hereinafter also referred to as "cooling water"). The reason is that the procurement is easy and inexpensive, and there are few dissolved components other than the main component.

The temperature of the liquid for cooling is not specifically limited, What is necessary is just a temperature lower than the said exhaust gas, and a lower one is preferable. For example, room temperature may be sufficient.

In addition, the temperature of the said cooling liquid shall mean the temperature just before providing to the cooling means mentioned later. The same applies to the components (sulfur, boron, fluorine, chlorine, etc.) and pH in the cooling liquid. The density | concentration of each component shall mean the value at the time of measuring using ICP analysis method, JISK0105 (1998), and JIS K0107 (2002). Temperature shall mean the value when it measures using the thermocouple. pH shall mean the value at the time of measuring using JIS Z8802 (1984).

PH of the said cooling liquid is not specifically limited. For example, when cooling liquid is water, it is preferable that pH is 5-9, It is more preferable that it is 6-8, It is further more preferable that it is 7-8. This is because boron and sulfur at normal temperature show high solubility at pH 7-8.

The sulfur concentration of the cooling liquid is not particularly limited. For example, when cooling liquid is water, it is preferable that it is 0-15000 ppm, and it is more preferable that it is 0-5000 ppm.

The boron concentration of the cooling liquid is not particularly limited. For example, when cooling liquid is water, it is preferable that it is 0-10000 mg / L, and it is more preferable that it is 0-5000 mg / L.

<Cooling means>

The cooling means will be described.

Cooling means is a means for cooling the exhaust gas in contact with the cooling liquid in the cooling step of the production method of the present invention.

The cooling means is not particularly limited, and examples thereof include spraying and bubbling. Especially, it is preferable that it is a means to contact the said exhaust gas with the said cooling liquid by spraying the said cooling liquid on the said exhaust gas. The cooling liquid is sprayed continuously while the exhaust gas is flowing at a rate of preferably 0.5 to 5 Nm 3 / s, more preferably 0.5 to 4 Nm 3 / s, and still more preferably 0.5 to 3 Nm 3 / s. do. This is because the heat exchange between the exhaust gas and the cooling liquid is efficiently performed by spraying the exhaust gas at this flow rate.

Here, it is preferable that the quantity L of the said cooling liquid with respect to the quantity Nm3 of the exhaust gas at the time of spraying is 0.5-1.0L / Nm3, It is more preferable that it is 0.6-0.8L / Nm3. It is more preferable that it is 0.6-0.7L / Nm <3>. This is because the heat exchange efficiency of the exhaust gas and the cooling liquid is maximum.

By the said cooling means, it is preferable to cool the said exhaust gas to the temperature which at least one part of boron in the said exhaust gas precipitates as a solid. It is preferable that this temperature is 90 degrees C or less, and it is preferable that it is 70 degrees C or more. Moreover, when it is 70 degreeC or more and 80 degrees C or less, it is more preferable at the point that most of boron does not precipitate as a solid, and when it is 70 degreeC or more and 75 degreeC or less, most of boron will not precipitate as a solid and in the next process More preferred in terms of reducing the load. That is, it is preferable that the temperature of exhaust gas after cooling mentioned later becomes this temperature.

By lowering to such a temperature, although a part of boron in the said exhaust gas precipitates normally in a solid (powder) form, in the manufacturing method of this invention, it is not necessary to necessarily deposit a large part of the boron in the said exhaust gas. In the conventional method, the boron in the exhaust gas can be almost separated even if the boron in the exhaust gas is reduced to 70 ° C. or lower, and most of it is reduced to 55 ° C. or lower as much as possible. This is because some of the sulfur and boron in the exhaust gas are dissolved in the cooling liquid because the exhaust gas is in contact with the cooling liquid, and the gaseous boron is forcibly forced into the contact liquid by a removal process described later. This is because it can be removed by dissolving it.

<Exhaust gas and cooling exhaust liquid after cooling>

By contacting the exhaust gas with the cooling liquid by such cooling means, the temperature of the exhaust gas is lowered, and at least a part of sulfur and boron contained in the exhaust gas are separated from the exhaust gas.

By applying such cooling means, exhaust gas and cooling discharge liquid after cooling can be obtained. The exhaust gas after cooling can reduce temperature by providing to the said cooling means, at least one part of sulfur and boron isolate | separates, and is exhaust gas after temperature falls. The cooling discharge liquid is a cooling liquid provided with the said cooling means to lower the temperature of the said exhaust gas, and to contain the sulfur and boron isolate | separated from the exhaust gas.

The sulfur, boron, fluorine and chlorine concentrations and temperatures of the exhaust gas after the cooling change depending on the concentration of each component in the exhaust gas, the processing conditions of the cooling means, etc., but the sulfur concentration is preferably 0 to 20 ppm, and preferably 0 to It is more preferable that it is 10 ppm, and it is still more preferable that it is 0-5 ppm. It is preferable that boron concentration is 0-200 mg / Nm <3>, It is more preferable that it is 0-100 mg / Nm <3>, It is still more preferable that it is 0-50 mg / Nm <3>. It is preferable that fluorine concentration is 0-20 mg / Nm <3>, It is more preferable that it is 0-10 mg / Nm <3>, It is still more preferable that it is 0-5 mg / Nm <3>.

It is preferable that chlorine concentration is 0-20 mg / Nm <3>, It is more preferable that it is 0-10 mg / Nm <3>, It is further more preferable that it is 0-5 mg / Nm <3>. It is preferable that it is 70-90 degreeC, It is more preferable that it is 70-80 degreeC, It is still more preferable that it is 70-75 degreeC. The reason is because of the heat resistance of the material having corrosion resistance to be described later and the temperature dependency of the removal load reduction and the removal ability in the next step.

In addition, the sulfur concentration, temperature, etc. of exhaust gas after cooling mean immediately after providing to the said cooling means. The measuring method of each component concentration and the measuring method of temperature are similar to the thing in the said exhaust gas.

Although the pH of the said cooling discharge liquid changes with sulfur concentration in the said exhaust gas, processing conditions, etc., it is preferable that it is 5-9, It is more preferable that it is 6-8, It is further more preferable that it is 7-8.

Since pH of the said cooling discharge liquid is such a value, it is preferable to perform the said cooling process with the apparatus which consists of an outer casing which has an inner wall made of corrosion-resistant material. Examples of the corrosion resistant material include FRP and stainless steel. Especially, FRP is more preferable.

In addition, each component concentration and temperature, such as pH and sulfur of a cooling discharge liquid, means immediately after providing to the said cooling means. These measuring methods are similar to the thing in the said cooling liquid.

The sulfur concentration of the cooling discharge liquid is not particularly limited. For example, when cooling liquid is water, it is preferable that it is 0-15000 ppm, and it is more preferable that it is 0-5000 ppm.

The boron concentration of the cooling discharge liquid is not particularly limited. For example, when cooling liquid is water, it is preferable that it is 0-10000 mg / L, and it is more preferable that it is 0-5000 mg / L.

<Specific form of cooling process>

It is preferable to perform such a cooling process with a cooling tower. The reason is to prevent the pressure loss of the exhaust gas. By spraying the cooling liquid on the exhaust gas in the cooling tower, the exhaust gas is cooled in the cooling tower, and a cooling discharge liquid containing sulfur and boron is stored at the bottom of the cooling tower. Therefore, it is preferable that at least the bottom of the inner surface of the outer casing of the cooling tower is made of FRP. Moreover, it is more preferable that the part which contact | connects the said exhaust gas, the said after-cooling gas, and the said cooling discharge liquid in the inside of the outer casing of a cooling tower is more preferable.

<Removal process>

Next, the removal process of the manufacturing method of this invention is demonstrated.

In the removing step, the cooling gas and the contact liquid are brought into contact with each other by a contact means to remove sulfur and boron from the exhaust gas after cooling, and the clean gas and the contact liquid after contact containing sulfur and boron are removed. Get

<Liquid contact liquid>

The said contact liquid is not specifically limited, What is necessary is just to be able to remove sulfur and boron from the said exhaust gas after cooling by contacting with the said exhaust gas after cooling by the contact means mentioned later. For example, water (including those which have water, such as industrial water and distilled water as a main component), and seawater are mentioned. Among these, the contact liquid is preferably water (hereinafter also referred to as "contact water"). The reason is that procurement is easy and inexpensive, and there are few dissolved components other than the main component.

The temperature of the said contact liquid is not specifically limited, What is necessary is just a temperature lower than the exhaust gas after the said cooling, and a lower one is preferable. For example, normal temperature may be sufficient.

In addition, the concentration and temperature of each component such as pH, sulfur, and the like of the contacting liquid mean immediately before being provided to the contacting means. These measuring methods are similar to the thing in the said cooling liquid.

PH of the said contact liquid is not specifically limited, either. For example, when cooling liquid is water, it is preferable that pH is 5-9, It is more preferable that it is 6-8, It is further more preferable that it is 7-8. This is because boron and sulfur at normal temperature show high solubility at pH 7-8.

The sulfur concentration of the contact liquid is not particularly limited. For example, when cooling liquid is water, it is preferable that it is 0-15000 ppm, and it is more preferable that it is 0-5000 ppm.

The boron concentration of the contact liquid is not particularly limited. For example, when cooling liquid is water, it is preferable that it is 0-10000 mg / L, and it is more preferable that it is 0-5000 mg / L.

<Contact means>

The contact means will be described.

The contact means is a means for contacting the exhaust gas after the cooling with the contact liquid in the removal step of the production method of the present invention.

A contact means is not specifically limited, For example, the spraying method and the bubbling method are mentioned similarly to the case of the said cooling process. Among these, and a spray liquid after the contact with the cooled exhaust gas, and thereafter, a mixed fluid of the liquid for the cooling and after the exhaust gas contacting the resulting, from 60 to 90m / s 50 to 300㎜H ₂ O It is preferable that it is a means to let it pass to the high differential pressure site | part which generate | occur | produces a pressure loss.

Here, it is preferable that the quantity L of the said contact liquid with respect to the quantity Nm of exhaust gas after cooling at the time of spraying is 0.5-2.5L / Nm <3>, and it is more that it is 1.0-2.0L / Nm <3>. It is preferable and it is more preferable that it is 1.5-2.0L / Nm <3>. The reason is that after cooling, the exhaust gas is dissolved in the contact liquid well.

Further, the pressure loss in the high differential pressure portion is preferably 50 to 300 mmH ₂ O at 60 to 90 m / s, more preferably 50 to 250 mmH ₂ O, more preferably 50 to 200 mmH ₂ O More preferably. If the pressure loss is within this range, the mixed fluid of the exhaust gas after the cooling and the contact liquid is in a turbulent state, and the exhaust gas after the cooling and the contact liquid are sufficiently mixed to form a gaseous phase in the exhaust gas after the cooling. This is because sulfur and boron can be efficiently transferred into the contact liquid. If the value of this pressure loss is too large, the droplets of the contact liquid generated by the spray are excessively coalesced, rather the surface area of the mixed fluid is reduced, and the contact time of the exhaust gas and the contact liquid after the cooling is reduced, The throughput of the exhaust gas decreases.

The high differential pressure portion, which generates a pressure loss of 50 to 300 mmH ₂ O at 60 to 90 m / s, refers to the flow of the mixed fluid in the flow path of the mixed fluid of the exhaust gas and the contacting liquid after the cooling. It is a site | part which inhibits and produces a pressure loss. For example, the site | part which provided the board | plate or rod in the flow path of the said mixed fluid, and the site | part which narrowed the flow path itself are mentioned. By adjusting the angle of the plate, the number of rods, etc. with respect to the flow direction of a fluid, it can adjust so that it may become said pressure loss.

<Clean gas and liquid after contact>

By such contact means, the exhaust gas after cooling is brought into contact with the liquid for contact, so that sulfur and boron contained in the exhaust gas after cooling are separated from the exhaust gas after cooling.

By applying such contact means, clean gas and post-contact discharge liquid can be obtained.

The clean gas is the exhaust gas after cooling after most of the sulfur and boron are separated after being provided to the contact means, and the exhaust liquid after contact lowers the temperature of the exhaust gas after cooling, and is separated from the exhaust gas after the cooling. It is a contact liquid that contains sulfur and boron.

Clean gas is a purified gas and the content of sulfur and boron is very low. In addition, the content of fluorine and chlorine is very low.

When the sulfur concentration in the clean gas is 30 ppm (in terms of O ₂ = 15% by volume), the sulfur concentration in the clean gas can be 1 ppm or less by making the treatment conditions in the cooling step and the removal step or the like preferable.

When the boron concentration of the said exhaust gas is 50 mg / Nm <3>, the boron concentration in clean gas can be 1 mg / Nm <3> or less by making the processing conditions in a cooling process, a removal process, etc. preferable.

When the fluorine concentration in the clean gas is 40 mg / Nm 3, the fluorine concentration in the clean gas can be 0.2 mg / Nm 3 or less by making the cooling conditions, the processing conditions in the removal step, and the like preferable.

When the chlorine concentration of the said exhaust gas is 50 mg / Nm <3>, the chlorine concentration in clean gas can be made into 0.2 mg / Nm <3> or less by making processing conditions in a cooling process, a removal process, etc. preferable.

Although the temperature of a clean gas is not specifically limited and heating is not necessary, It is preferable that it is 75 degrees C or less, It is more preferable that it is 70 degrees C or less, It is further more preferable that it is 60 degrees C or less. The reason is to aggregate the moisture in the exhaust gas.

In addition, the sulfur concentration, temperature, etc. of a clean gas mean immediately after providing it to the said contact means.

The measuring method of each component concentration and the measuring method of temperature are similar to the thing in the said exhaust gas.

The pH of the discharged liquid after contact varies depending on the sulfur concentration in the exhaust gas after the cooling, treatment conditions, and the like, but is preferably 5 to 9, more preferably 6 to 8, and even more preferably 7 to 8.

Since the pH of the discharged liquid after contact is such a value, it is preferable that the removal step is performed with an apparatus consisting of an outer casing having an inner wall made of a corrosion resistant material. Examples of the corrosion resistant material include FRP and stainless steel. Especially, FRP is more preferable.

In addition, the concentration and temperature of each component such as pH and sulfur of the discharged liquid after contacting means immediately after providing the contacting means. These measuring methods are similar to the thing in the said cooling liquid.

The sulfur concentration of the discharged liquid after contacting is not particularly limited. For example, when cooling liquid is water, it is preferable that it is 0-15000 ppm, and it is more preferable that it is 0-5000 ppm.

The boron concentration of the discharged liquid after contacting is not particularly limited. For example, when cooling liquid is water, it is preferable that it is 0-10000 mg / L, and it is more preferable that it is 0-5000 mg / L.

<Specific form of removal process>

Such a removal process can be performed with a venturi scrubber, a cyclone scrubber, a jet scrubber, etc. Especially, it is preferable to carry out by a venturi scrubber. The reason is that the structure is easy, the operating cost is low, and the removal efficiency is high. By spraying the contact liquid to the exhaust gas after cooling in a venturi scrubber and passing the high differential pressure portion, sulfur and boron are separated and removed from the exhaust gas after cooling in a venturi scrubber, and the venturi scrubber At the bottom of the discharged liquid is stored after contact which contains sulfur and boron. Therefore, at least the bottom of the inner wall of the venturi scrubber is preferably made of FRP. In addition, it is more preferable that the portion of the venturi scrubber that is in contact with the exhaust gas after cooling and the exhaust liquid after contact is made of FRP.

<Separation process>

In the manufacturing method of this invention, in addition to the said cooling process and the said removal process, it is preferable to further provide the separation process which isolate | separates the liquid which remain | survives in the said clean gas, and collect | recovers as a discharge liquid after cleaning. In the clean gas, the liquid mainly remains in the mist phase, but the mist liquid is agglomerated in the clean gas flow path (exhaust gas pipe, etc.) after the removal process and before the air is discharged from the chimney or the like, and the liquid flows into the liquid. This is because there is a possibility to seal with.

The means for separating the liquid remaining in the clean gas is not particularly limited, but means for separating the mist-like liquid from the clean gas using a centrifugal force, cyclone or the like can be applied. Especially, the method of applying a centrifugal force dust collector is preferable. This is because the misty liquid can be separated efficiently.

In addition, the separated liquid may have a relatively low pH to the same extent as the discharged liquid after the contact. Therefore, it is preferable to perform a separation process in the apparatus which consists of an outer casing whose inner wall is made of FRP.

<Reuse of Drain Liquid>

In the manufacturing method of this invention, at least 1 sort (s) of the said cooling discharge liquid, the said after-contact discharge liquid, and the said after discharge liquid is collect | recovered, a pH, sulfur concentration, and a boron concentration are managed and adjusted, the said cooling means, and And / or reuse in the contact means as a cooling liquid and / or a contact liquid.

It is preferable that pH, sulfur concentration, and boron concentration of the cooling liquid and the contact liquid at the time of reuse are the preferable values at the time of using each liquid shown above. Adjustment of pH, sulfur concentration, and boron concentration can be performed by a conventional method. If pH is too low, it can adjust by adding caustic soda. If the sulfur concentration or the boron concentration is too high, it can be lowered by adding water.

In addition, it is preferable to separate sulfur and / or boron from at least one of the cooling discharge liquid, the post-contact discharge liquid and the clean discharge liquid, and reuse it as a glass raw material.

<Clean gas discharge method>

Since the said clean gas obtained by the said removal process or the clean gas after processing in the said separation process is purified as mentioned above, it can dissipate to air | atmosphere.

Moreover, in the manufacturing method of this invention, the temperature of the clean gas at the time of dissipation can be 70 degrees C or less. It is because sulfur content in clean gas is low, and even if it is the temperature below an acid dew point, it is difficult to corrode the clean gas flow paths, such as piping. When sulfur content in clean gas is comparatively high like the conventional method, it is necessary to heat clean gas temperature to about 150 degreeC, but the manufacturing method of this invention does not require the installation for performing such heating.

In addition, the clean gas is preferably discharged from the chimney to the atmosphere using a fan. The reason is that when a large amount of the above clean gas is emitted, it is difficult to dissipate to the atmosphere only by the draft effect of the chimney. Moreover, it is preferable that the said fan can control the dissipation amount of the said clean gas in conjunction with the said high differential pressure part in the said removal process. This is because, in order to stabilize the quality of the glass, the amount of air flow of the exhaust gas from the glass melting furnace must be controlled to be constant. This has the following meaning. When the differential pressure of the high differential pressure portion is determined, the amount of dissipation of the clean gas by the fan is determined. However, when the concentrations of sulfur, boric acid, fluorine and chlorine contained in the exhaust gas and the temperature fluctuate, the pressure loss conditions at other places other than the pressure loss at the high pressure difference site are changed. As a result, the amount of dissipation of the clean gas is changed. For this reason, it is preferable to be able to control in conjunction with a pressure loss.

<Other process>

The other process in the manufacturing method of this invention may be the same as the process with which the manufacturing method of a normal glassware is equipped.

For example, a melting process of melting a glass raw material to generate molten glass while generating the exhaust gas, a molding process of molding the molten glass into a shape of a predetermined glass product, and a slow cooling process of gradually cooling while removing internal distortion of the glass product. And a cutting step.

Melting process is a process of mixing and mixing raw materials, such as silica sand, limestone, and soda ash, according to the composition of a glass product, into a glass melting furnace, and heating and melting it to about 1400 degreeC or more according to the kind of glass, and obtaining molten glass. . For example, in a known melting furnace, a batch is introduced from one end of the furnace, a flame obtained by burning heavy oil is injected into the injected batch, and a flame obtained by burning by mixing natural gas with air is injected, The molten glass can be obtained by heating to about 1550 degreeC or more, and melt | dissolving a batch. The manufacturing method of this invention removes a predetermined | prescribed component from the exhaust gas which generate | occur | produces in this melting furnace, and discharges the clean gas below the predetermined | prescribed concentration which remain | survived from a chimney.

The exhaust gas generated in the glass melting furnace may be provided to the cooling step after passing through a dust collector such as a bag filter.

Although a shaping | molding process has a float method and a roll out method as a well-known technique, any one or another method may be sufficient. Hereinafter, when a float method is demonstrated as an example, in a shaping | molding process, molten glass is introduce | transduced into the molten tin bath from the downstream part of a melting furnace, the molten glass floats on molten tin, it advances, and it shape | molds with a glass ribbon. In the shaping | molding process, in order to shape | mold the glass ribbon thinner than the equilibrium thickness of a molten glass, the rotating roll called a top roll is pressed to the both ends of the width direction orthogonal to a traveling direction, and tension is applied in the width direction, and molten tin The glass ribbon on the top can also be stretched in the advancing direction while suppressing the width from being reduced.

The following slow cooling process is a process after taking out a glass ribbon from molten tin with a lift out roll after shaping | molding. Slow cooling is performed in the slow cooling furnace or air | atmosphere provided with the metal roll as a conveyance mechanism of a glass ribbon, and the mechanism for gradually lowering the temperature of a glass ribbon. The mechanism which gradually lowers the temperature supplies the amount of heat whose output is controlled by the combustion gas or the electric heater to the required position in the furnace, and slowly cools the glass ribbon to a temperature region close to normal temperature. Thereby, the residual stress inherent in a glass ribbon can be eliminated.

Cutting is a process performed in order to plate a glass product in a desired size.

Moreover, in the process of melt | dissolving a glass raw material in a glass melting furnace, the inside of a glass melting furnace is made into oxygen atmosphere, and the glass raw material is heated and made into molten glass by the burner flame which burned the heavy oil containing sulfur normally. In the case, the effect of the manufacturing method of this invention is high. This is because, in the case of oxygen combustion, the ratio of vaporized boron or boron compound in the exhaust gas is about 1.7 times higher than that of air combustion.

Moreover, in the manufacturing method of this invention, it is not necessary to use an electrostatic precipitator like the conventional method. The reason for this is that the dust is also washed out with the cooling discharge liquid and the discharge liquid after contact. Therefore, the effect of removing the dust is also exhibited. In addition, as mentioned above, in the manufacturing method of this invention, it is not necessary to necessarily heat the boric acid or exhaust gas which precipitated in a series of process. Therefore, compared with the conventional method which requires reheating, the cost at the time of operation also exhibits the effect which can be made low.

(Example)

The manufacturing method of this invention is demonstrated more concretely based on an Example. However, the present invention is not limited to the following examples. In addition, in the following description, it abbreviate | omits about the process with which the manufacturing method of normal glassware, such as a shaping | molding process, a slow cooling process, and a cutting process in the manufacturing method of this invention, is equipped.

1 is a schematic view of the production method of the present invention. In FIG. 1, the exhaust gas 12 generated from the glass melting furnace 10 during the melting process is supplied to the cooling tower 16 at a gas temperature of 135 to 155 ° C. via the bag filter 14.

In the cooling tower 16, the cooling water 18 is dispersed and contacted with the exhaust gas 12 at 1 to 3 m 3 / h per spray and 3 to 3 9 m 3 / h in total.

And the exhaust gas 20 after cooling cooled to 65-90 degreeC is supplied to the venturi scrubber 24 through the piping 22. As shown in FIG. In addition, the cooling water 18 after cooling the exhaust gas 12 is set to a water temperature of 60 to 70 ° C, and is stored as the cooling discharge liquid 26 at the bottom of the cooling tower 16. The cooling discharge liquid 26 is withdrawn from the bottom of the cooling tower 16 through the pipe 28 attached to the bottom, and collected in the tank 30.

After the cooling of the exhaust gas 20 supplied to the venturi scrubber 24 via the pipe 22, the contact water 27 is 7 to 10 m 3 / h per spray and 21 to 30 m 3 / h in total of three. Is scattered. And, 50 to the high 180㎜H set to ₂ O through the differential pressure region (29), it is supplied to the centrifugal force, the dust collector 32 as clean gas 31 at a temperature of 65 to 70 ℃, liquid (water), the venturi After contact with the bottom of the scrubber 24 is stored as the discharge liquid 34. After contact, the discharge liquid 34, like the cooling discharge liquid 26, is withdrawn from the bottom of the venturi scrubber 24 through the pipe 36 attached to the bottom and collected in the tank 30.

The clean gas 31 supplied to the centrifugal force precipitator 32 is freed of mist-like water in the centrifugal force precipitator 32 and discharged to the atmosphere as a clean gas having a temperature of 60 to 70 ° C through the chimney 37. There is a fan 39 between the chimney 37 and the centrifugal force dust collector 32, whereby the gas flow rate passing through these devices can be adjusted. Although the adjustment amount of gas flow volume is determined according to the capacity of exhaust gas, it can also adjust in the range of 9000-11000 Nm <3> / h in a comparatively large melting furnace.

Mist-like water 38 is stored in the bottom of the centrifugal force dust collector 32. This water 38 is extracted from the bottom of the centrifugal dust collector 32 through the pipe 40 attached to the bottom, and collected in the tank 30, similarly to the cooling discharge liquid 26 and the post-contact drainage 34. Lose.

The water collected in the tank 30 adjusts pH to 6-8 in a tank. The tank 30 is equipped with a pH meter 42 and a NaOH addition device 44.

The pH adjusted water in the tank 30 is reused as cooling water 18 and contact water 27 at a water temperature of 60 to 70 ° C.

Next, based on the schematic diagram of the manufacturing method of this invention shown in FIG. 1, the apparatus provided with a cooling process and a removal process is produced, and the result which confirmed the effect of this invention is demonstrated. This apparatus was attached to the glass melting furnace and other manufacturing facilities of a well-known technique. Then, the effect was confirmed three times the next day. Below, the outline | summary and the result of the test conditions used in implementation are shown.

Volume of exhaust gas: about 10000 Nm3 / h

H ₂ O in exhaust gas: 25 vol%

Average temperature of exhaust gas just before cooling tower: 150 ° C

Total spray amount in cooling tower: 6㎥ / h

Exhaust gas temperature after cooling at the inlet of a venturi scrubber: 69, 74, 77 ° C

Average velocity of mixed fluid in venturi scrubber: 75 m / s

Pressure loss in venturi scrubbers: 58, 96, 174 mmH ₂ O

Total volume of spray from venturi scrubber: 23㎥ / h

Average temperature of clean gas at the outlet of the venturi scrubber: 66 ° C

Under the above conditions, SOx is about 13 ppm before the cooling step and the removing step, boric acid (B ₂ O ₃ ) is 93 to 164 mg / Nm 3, boron is 29 to 51 mg / Nm 3 (B ₂ O ₃ equivalent), The fluorine was 0.66 mg / Nm3 and the chlorine (HCL equivalent) was 0.69mg / Nm3, but after the removal process, SOx averaged 1ppm or less, boric acid (B ₂ O ₃ ) averaged 3mg / Nm3, and boron averaged 1mg / Nm 3 (B ₂ O ₃ equivalent), fluorine was 0.15 mg / Nm 3 or less, and chlorine (HCL equivalent) was 0.25 mg / Nm 3. The measurement of temperature and concentration was based on the method mentioned above. In addition, the concentration of fluorine and chlorine was measured only once.

2 shows the relationship between the pressure loss and the removal rate of B ₂ O _{3 in} the apparatus described above. The ratio of the removal rate is the venturi scrubber B ₂ O ₃ per unit volume of weight at the inlet (mg / N㎥), removal of the removed unit of B ₂ O ₃ after the processing volume for the sugar weight (mg / N㎥) Indicates. In this FIG. 2, in addition to the above-mentioned three times, data in the case where the pressure loss was 4.2 mmH ₂ O was added. In this case, the exhaust gas temperature after cooling at the inlet of the venturi scrubber was 77 ° C. Other conditions were made the same as the above. From Figure 2, it was found that the pressure loss is at least 50㎜H ₂ O or more preferred. Further, the removal rate and found to be that the rate of increase in pressure loss 200㎜H ₂ O or more smaller. In addition, if the value of the pressure loss is too large, the droplets of the contacting liquid generated by the spray are excessively coalesced, so that the surface area of the mixed fluid is reduced, and the contact time of the exhaust gas and the contacting liquid after cooling is reduced, and the exhaust gas is reduced. Will reduce the throughput.

Moreover, based on the schematic diagram of the manufacturing method of this invention shown in FIG. 1, the apparatus provided with the cooling process and the removal process is produced, and it is small separate from the glass melting furnace of the well-known technique used in the above-mentioned implementation, and other manufacturing facilities. The results of confirming the effect of the present invention will be described with reference to the installation of the present invention. 3 shows the relationship between the temperature of the exhaust gas after cooling obtained in the practice and the removal efficiency of B ₂ O ₃ . 3 is a result of performing 14 times under the following conditions. The removal rate is the same definition as the above.

Volume of exhaust gas: about 1000 Nm3 / h

H ₂ O in exhaust gas: 25 vol%

Average temperature of exhaust gas immediately before cooling tower: 145 to 150 ° C

Total spray amount in cooling tower: 0.6㎥ / h

Average velocity of mixed fluid in venturi scrubber: 75 m / s

Average pressure loss in the venturi scrubber: 50 to 100 mmH ₂ O

Total volume of spray from venturi scrubber: 2.2㎥ / h

Clean gas average temperature at the outlet of the venturi scrubber: 65 to 70 ° C

From the result of FIG. 3, even when the temperature of exhaust gas after cooling is 70 degreeC or more, it turned out that the removal efficiency similar to the case of the temperature below that is obtained is obtained. Moreover, when cooling gas temperature exceeded 90 degreeC after cooling, it turned out that removal efficiency tends to fall remarkably.

From the above results, according to the present embodiment, even when sulfur is contained in exhaust gas at a high concentration by the production method of the present invention, sulfur and boron can be simultaneously removed from the exhaust gas, and a lot of moisture is contained in the exhaust gas. It was confirmed that the manufacturing method for obtaining a boron containing glass product provided with the process applicable also when included was provided. Moreover, according to the present Example, even if the exhaust gas temperature after cooling is 70 degreeC or more, it turned out that high removal efficiency is obtained. In addition, it was confirmed that the production method of the boron-containing glass product which can simultaneously remove sulfur, boron, fluorine and chlorine from the exhaust gas can be provided by the production method of the present invention.

Although this invention was detailed also demonstrated with reference to the specific embodiment, it is clear for those skilled in the art that various changes and correction can be added without deviating from the mind and range of this invention.

This application is based on the JP Patent application 2007-314386 of an application on December 5, 2007, The content is taken in here as a reference.

10: glass melting furnace
12: exhaust gas
14: bag filter
16: cooling tower
18: cooling water
20: exhaust gas after cooling
22: piping
24: Venturi Scrubber
26: cooling discharge liquid
27: contact water
29: high pressure difference site
28: plumbing
30: tank
31: clean gas
32: Centrifugal Dust Collector
34: Drain liquid after contact
36: plumbing
37: chimney
38: moisture
39: fan
40: piping
42: pH meter
44: NaOH addition apparatus
46: circulating pump

Claims (15)

A cooling step of cooling the exhaust gas containing sulfur and boron generated from the glass melting furnace by a cooling means in contact with the cooling liquid to obtain the exhaust gas after cooling and a cooling discharge liquid containing sulfur and boron, and
A removal step of contacting the exhaust gas with the contacting liquid after the cooling by means of a contact means to remove sulfur and boron from the exhaust gas after the cooling and obtaining a clean gas and a post-contact exhaust liquid containing sulfur and boron. The manufacturing method of a boron containing glass article provided. The manufacturing method of the boron containing glassware of Claim 1 provided with the process of supplying the glass raw material containing 0.1 mass% or more of sulfur to the said glass melting furnace. The manufacturing method of the boron containing glassware of Claim 1 or 2 whose temperature of the said exhaust gas after cooling in the said cooling process is 90 degrees C or less. The manufacturing method of the boron containing glass article of any one of Claims 1-3 whose temperature of the exhaust gas after cooling in the said cooling process is 70 degreeC or more. The manufacturing method of the boron containing glass article of any one of Claims 1-4 whose temperature of the said clean gas is 50-70 degreeC. The method for producing a boron-containing glass product according to any one of claims 1 to 5, wherein the cooling means is a means for spraying the cooling liquid to contact the exhaust gas with the cooling liquid. The boron-containing glass product according to claim 6, wherein the amount L of the cooling liquid with respect to the amount N 3 of the exhaust gas when spraying the cooling liquid is 0.5 to 1.0 L / Nm 3. Manufacturing method. The said contact means sprays the said contact liquid on the said exhaust gas after cooling, Then, the obtained mixed fluid of the said after cooling exhaust gas and the said contact liquid is carried out. A method for producing a boron-containing glass article, which is a means for passing through a high differential pressure site that generates a pressure loss of 50 to 300 mmH ₂ O at 60 to 90 m / s. The boron-containing glass according to claim 8, wherein the amount L of the contacting liquid with respect to the amount of exhaust gas after cooling (Nm 3) when spraying the contacting liquid is 0.5 to 2.5 L / Nm 3. Method of manufacture of the product. 10. The cooling means and / or the contacting means according to any one of claims 1 to 9, wherein the cooling discharge liquid and / or the discharge liquid after contacting are recovered, and the pH, sulfur concentration and boron concentration are managed. A method for producing a boron-containing glass article, which is reused as a cooling liquid and / or a contact liquid. The method for producing a boron-containing glass article according to any one of claims 1 to 10, wherein the boron-containing glass is an alkali free glass. The boron-containing glass product according to any one of claims 1 to 11, further comprising a separation step of separating the cooling liquid and the contact liquid remaining in the clean gas and recovering the liquid as a discharged liquid after cleaning. Method of preparation. The method for producing a boron-containing glass product according to claim 12, wherein the cooling step is a cooling tower, the removal step is a venturi scrubber, and the separation step is performed by a centrifugal force dust collector. The exhaust gas containing sulfur and boron generated from the glass melting furnace is cooled to a temperature at which at least a portion of boron precipitates as a solid by cooling means for contacting with the cooling water, followed by cooling drainage containing sulfur and boron, and after cooling A cooling step of obtaining exhaust gas,
And a removal step of contacting the exhaust gas after the cooling with the contact water by means of a contact means to remove sulfur and boron from the exhaust gas after the cooling, and to obtain contact drainage containing sulfur and boron, and a clean gas. A method for purifying exhaust gas generated in the production of boron-containing glass products, wherein sulfur and boron are removed from the exhaust gas generated from the glass melting furnace. 15. The method of claim 14, wherein the exhaust gas generated from the glass melting furnace further comprises fluorine and chlorine, and wherein the exhaust gas generated from the glass melting furnace removes sulfur, boron, fluorine and chlorine from the exhaust gas generated from the glass melting furnace. How to purify exhaust gas.

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