CN1391642A

CN1391642A - Stack structure

Info

Publication number: CN1391642A
Application number: CN00815819A
Authority: CN
Inventors: 北野善一
Original assignee: KK Maruki
Current assignee: KK Maruki
Priority date: 1999-11-19
Filing date: 2000-11-17
Publication date: 2003-01-15
Also published as: WO2001038788A1

Abstract

The invention aims to provide a chimney structure capable of preventing carbon dioxide causing global warming from being exhausted into the atmosphere, wherein: a porous stack is disposed in a pipe body having a base end communicating with a combustion chamber. In addition, the pipe body is formed by bending it in an inverted U-shape, and a porous stack is disposed in the combustion gas flow path.

Description

Chimney structure

Technical Field

The present invention relates to a chimney structure capable of reducing the height of a chimney by half and removing harmful carbon dioxide in combustion gas.

Background

Conventionally, chimneys of up to several tens of meters have been often installed in refuse incinerators and the like.

In general, harmful substances such as dust and ash scattered from a chimney are scattered in the air so as not to affect the nearby area, but this incurs a large construction cost.

In recent years, environmental pollution caused by exhaust gas from a chimney or the like has become a global problem, and various studies have been made in the relevant departments.

Among them, many studies have been made on the problem of preventing the generation of dioxin from garbage incineration or the like, and incinerators capable of greatly reducing the generation of dioxin have been developed.

However, the present situation is that of carbon dioxide (CO) contained in the exhaust gas of the chimney₂) Are hardly considered.

Carbon dioxide itself is a major component of the atmosphere and is not considered to be a problem because it does not have a direct adverse effect on the human body, unlike dioxin and other harmful substances. However, in recent years, carbon dioxide in the atmosphere has increased rapidly, which causes a serious problem of global warming.

It is difficult to change the lifestyle and production system of human beings, and it is impossible to incinerate garbage or supply all energy without generating carbon dioxide.

Therefore, measures must be taken to cut down carbon dioxide in the atmosphere.

Disclosure of Invention

In order to solve the above problem, a chimney structure according to claim 1 is characterized in that a porous stack (stack/スタツク) is disposed in a pipe body having a base end communicating with a combustion chamber and a tip end provided with an exhaust port to form a combustion gas flow path. Therefore, the stack produces a dream (dream pipe) effect accompanied by heat transport, thereby greatly reducing the temperature at the outlet of the chimney and preventing secondary generation of dioxin. Therefore, the chimney can be used in a small-sized incinerator or the like, and the chimney height can be reduced and the construction cost can be suppressed even in a large-sized incinerator.

The chimney structure according to claim 2, wherein the pipe body is bent in an inverted U-shape, and a porous laminate is disposed in a combustion gas flow path formed in the pipe body. Therefore, the height of the chimney can be further reduced, and even if the exhaust port is close to the ground, the fantasy pipe effect accompanying heat transfer is obtained by arranging the laminated member, so that the chimney outlet temperature can be greatly reduced, and the adverse effects of soot and high-temperature gas can be eliminated.

A chimney structure according to claim 3, wherein an upper end of the inner cylinder is open, a base end of the inner cylinder communicates with the combustion chamber, the inner cylinder is enclosed in the outer cylinder, an upper end of the outer cylinder is closed, the exhaust port is formed in a middle portion of the outer cylinder, the tubular flow passage inside the inner cylinder communicates with an annular flow passage formed between the inner cylinder and the outer cylinder to form a combustion gas flow passage, and the porous laminate is disposed in the combustion gas flow passage. Therefore, the chimney can ensure the necessary length of the exhaust flow path, and can be made into a double structure with half height, thereby reducing the height and suppressing the construction cost. Further, by providing the stack, the fantasy pipe effect accompanying heat transfer is obtained, and the chimney outlet temperature can be greatly reduced, so that even if the exhaust port is located at a low position close to the floor, there is no adverse effect of soot and high-temperature gas. Further, since the double pipe structure is constituted by the tubular flow path and the annular flow path, the sound frequencies generated in the respective flow paths can be cancelled out, and therefore, the noise generated by the illusion pipe effect can be muted.

The chimney structure according to claim 4, wherein a filter is disposed in the combustion gas flow path. Thus, soot and dust may be absorbed and clean exhaust gas may be discharged.

The chimney structure according to claim 5, wherein the exhaust port is connected to an exhaust gas treatment device. Therefore, the exhaust gas becomes clean exhaust gas, and does not cause environmental pollution.

The chimney structure according to claim 6, wherein a blower is provided in the exhaust port. Therefore, the exhaust gas of the combustion chamber can be efficiently guided to the exhaust gas treatment device.

The chimney structure according to claim 7, wherein the laminated member is formed of a porous ceramic. Therefore, the laminate can be easily obtained by using the existing material as a laminate, and the dream-fighting effect can be further improved.

The chimney structure according to claim 8, wherein the exhaust gas treatment device is a gas generation unit, and the gas generation unit generates methane gas by generating a carbon dioxide reduction reaction with water in the presence of the photocatalyst. Therefore, carbon dioxide is not released into the atmosphere, and carbon dioxide is changed into methane gas, which can be effectively used as an external energy source such as an electric power source and a heat source.

The chimney structure according to claim 9, wherein the gas generating section comprises a combustion gas containing chamber, a water tank section communicating with the combustion gas containing chamber, and a methane gas purifying chamber communicating with the water tank section, and a photocatalyst having palladium supported on a titanium oxide surface is dispersed in the water tank section. That is, by using a semiconductor photocatalyst which is a solid capable of accumulating many electrons, carbon dioxide can be efficiently reduced, and the efficiency of methane gas generation can be improved.

The chimney structure according to claim 10, wherein the exhaust gas treatment device is a carbon dioxide recovery tank which contains a treatment liquid for dissolving calcium hydroxide and which is capable of recovering carbon dioxide contained in the combustion gas as calcium carbonate. Therefore, carbon dioxide generated by combustion can be recovered in a stable state.

The chimney structure according to claim 11, wherein the carbon dioxide recovery tank is maintained at a negative pressure. Therefore, the combustion gas can be efficiently introduced into the carbon dioxide recovery tank.

The chimney structure according to claim 12, wherein the exhaust gas treatment device passes NO_xThe decomposition catalyst of (3) separates the exhaust gas into nitrogen gas and carbon dioxide, and reacts the separated carbon dioxide with hydrogen generated from the hydrogen generator to produce methanol. Therefore, carbon dioxide is converted into methanol without being discharged to the atmosphere, and can beeffectively used as electricityExternal energy sources such as a force source and a heat source are utilized.

The chimney structure according to claim 13, wherein the exhaust gas treatment device passes NO_xThe decomposition catalyst (2) separates the exhaust gas into nitrogen gas and carbon dioxide, and reacts the separated carbon dioxide with hydrogen generated from the hydrogen generator to produce carbon. Thus, carbon dioxide is not emitted to the atmosphere, and carbon as a pure resource may be used instead.

The chimney structure according to claim 14, wherein a cooling circuit for cooling the surface of the stack is provided. Therefore, the exhaust gas temperature can be effectively lowered.

Drawings

FIG. 1 is a schematic explanatory view of a chimney structure according to embodiment 1.

Fig. 2 is a schematic explanatory view of a chimney structure of embodiment 2.

Fig. 3 is an explanatory diagram showing a modification of the exhaust gas treatment device in embodiment 2.

FIG. 4 is a schematic explanatory view of a chimney structure according to embodiment 3.

Fig. 5 is an explanatory diagram showing a modification of the exhaust gas treatment device in embodiment 3.

FIG. 6 is a schematic explanatory view of a chimney structure according to embodiment 4.

Fig. 7 is an explanatory diagram showing a modification of the exhaust gas treatment device in embodiment 4.

Fig. 8 is an explanatory diagram showing a modification of the exhaust gas treatment device in embodiment 4.

FIG. 9 is a schematic explanatory view of a chimney structure according to embodiment 5.

Fig. 10 is an explanatory diagram of the stack cooling mechanism.

Best mode for carrying out the invention

In one embodiment of the chimney structure of the present invention, a porous stack is disposed in a tube body forming a combustion gas flow path, the tube body having a base end communicating with a combustion chamber and a tip end provided with an exhaust port. The tube body may be of an upright configuration or of a slightly inclined configuration.

That is, by disposing the porous laminate in the pipe body, the high-temperature exhaust gas can be cooled to normal temperature near the chimney exit by the magic pipe effect, and thus secondary generation of dioxin can be prevented. In addition, the stack can also be used to trap soot, dust, etc.

Therefore, the chimney can be made lower, and the construction cost can be greatly reduced.

In addition, this structure can be adopted in a small-sized incinerator, and can be easily installed in a school or other facilities.

Further, the tube body may be bent in an inverted U-shape, and the porous laminated member may be disposed in a combustion gas flow path in the tube body.

That is, the conventional chimney which rises upward is eliminated, the pipe body formed as the chimney is bent downward halfway to form an inverted U-shape, and the illusion pipe effect by the porous laminate disposed inside the pipe body enables the high-temperature exhaust gas to be cooled to normal temperature and also enables soot, dust, and the like to be collected by the laminate. Therefore, the chimney can be made to be a low chimney, and the front end part as the exhaust port is positioned near the ground, so that the construction cost can be greatly reduced in a garbage incineration site and the like.

The above-described laminate may be formed of porous ceramics. That is, since conventional materials such as a catalyst disposed in an exhaust pipe of an automobile can be used as a laminate, the laminate is easily obtained and the fantasy pipe effect can be further improved.

Further, the tube may be bent in an inverted U-shape, and the porous laminated member may be disposed in a combustion gas flow path in the tube. The chimney structure bent in the inverted U shape can reduce the height of the chimney, and the front end part as the exhaust port is positioned near the ground, so that the construction cost can be greatly reduced.

In addition, a cooling circuit for cooling the surface of the stack may be provided. With this cooling circuit, the exhaust gas temperature can be reduced more effectively.

Further, the exhaust port may communicate with an exhaust gas treatment device to remove harmful substances contained in the exhaust gas and discharge the removed harmful substances into the atmosphere. At this time, when the temperature of the exhaust gas at the inlet of the exhaust gas treatment device is as high as 300 ℃, dioxin is generated in the treatment device, and therefore, according to the present invention, which can cool the exhaust gas, the generation of dioxin can be effectively prevented.

In addition, a filter dedicated to soot and dust may be provided in the tube body in addition to the laminated member. The arrangement position may be arranged on either the upstream side or the downstream side of the stack, or both, as necessary.

Further, if the combustion chamber is constructed so as to be capable of high temperature combustion at 1000 to 1500 ℃, dioxin, which has been a problem in recent years, can be removed in the combustion chamber.

Further, a blower may be provided at the exhaust port. That is, the exhaust gas in the combustion chamber is forcibly sucked by the blower and can be efficiently guided to the exhaust gas treatment device.

Further, since the present invention is directed to preventing carbon dioxide that warms the earth from being discharged into the atmosphere, the exhaust gas treatment device described above can be configured as follows.

That is, the exhaust gas treatment device is used as a gas generation unit, and a carbon dioxide reduction reaction is generated in the gas generation unit using water using a photocatalyst to generate methane gas.

The gas generating section comprises a combustion gas containing chamber, a water tank section communicating with the combustion gas containing chamber, and a methane gas purifying chamber communicating with the water tank section, and a photocatalyst having palladium supported on the surface of titanium oxide is dispersed in the water tank section, whereby water can be used as a reducing agent, and a semiconductor photocatalyst which is a solid capable of accumulating many electrons is used, whereby carbon dioxide can be efficiently reduced, and the efficiency of methane gas generation can be improved.

As described above, according to the present invention, carbon dioxide is converted into methane gas without being discharged into the atmosphere, and thus, carbon dioxide can be effectively used as external energy such as an electric power source and a heat source.

As described above, the chimney height can be reduced, the construction cost can be suppressed, and the environment can be protected. Further, since the chimney exit temperature is greatly reduced, even if the exhaust outlet is close to the ground, there is no adverse effect of soot and high-temperature gas. The above-described illusion tube effect is analyzed by a thermo-acoustic theory in recent research.

As another example of the exhaust gas treatment device, the following structure may be adopted.

That is, the exhaust gas treatment device is used as a carbon dioxide recovery tank in which a treatment liquid in which calcium hydroxide is dissolved is contained, and carbon dioxide contained in the combustion gas can be recovered as carbon and calcium.

The carbon dioxide reacts with the calcium hydroxide to produce calcium carbonate and water. Calcium carbonate acts as a carbon dioxide reservoir, existing in a naturally stable form as calcite.

Therefore, carbon dioxide generated by combustion can be recovered in a stable state without being discharged into the atmosphere.

In general, a desulfurizer is disposed in the combustion chamber, and calcium carbonate is used as an absorbent in the desulfurizer, and in this case, it is mixed with SO in the exhaust gas_XThe reaction can obtain gypsum as a byproduct.

Further, when calcium hydroxide (slaked lime) is dissolved in water, it is preferably at a low temperature, and as described above, the exhaust gas temperature can be greatly lowered by the magic tube effect, so that the amount of calcium hydroxide dissolved in the treatment liquid can be secured.

The carbon dioxide recovery tank may be provided in a plurality of tanks in series as necessary.

Further, it is preferable that the negative pressure is maintained in the carbon dioxide recovery tank so that the combustion gas from the combustion chamber passing through the inverted U-shaped pipe body can be efficiently introduced without providing the above-mentioned blower.

In another embodiment of the exhaust gas treatment device, the exhaust gas may be separated into nitrogen gas and carbon dioxide gas by a NOx decomposition catalyst, and the separated carbon dioxide gas may be reacted with hydrogen generated from a hydrogen generator to produce methanol.

In addition, as the exhaust gas treatment device, the exhaust gas may be separated into nitrogen gas and carbon dioxide by a NOx decomposition catalyst, and the separated carbon dioxide may be reacted with hydrogen generated from the hydrogen generator to generate carbon.

According to this structure, carbon dioxide is recovered as a pure resource without being discharged into the atmosphere, and can be effectively used.

In addition, as an embodiment of the chimney structure of the present invention, an upper end of the inner cylinder may be open so that a base end of the inner cylinder communicates with the combustion chamber, the inner cylinder may be enclosed in the outer cylinder, an upper end of the outer cylinder may be closed, the exhaust port may be formed in the middle of the outer cylinder, the combustion gas flow path may be formed by communicating a tubular flow path inside the inner cylinder with an annular flow path formed between the inner cylinder and the outer cylinder, and the porous laminated member may be disposed in the combustion gas flow path.

According to this structure, the necessary length of the exhaust gas flow path can be secured, and the height can be reduced by half, thereby reducing the chimney height and suppressing the construction cost. In this case, a vertical chimney structure can be provided, and installation space can be saved even in a large chimney.

In this case, the stack may be provided, and the stack may provide a fantasy pipe effect associated with heat transfer, thereby significantly reducing the stack outlet temperature and preventing the adverse effects of soot and high-temperature gas from being generated even when the exhaust outlet is at a low position close to the floor surface.

Further, as described above, the exhaust port of the chimney is connected to the exhaust gas treatment device so as to prevent carbon dioxide that warms the earth from being emitted into the atmosphere.

In the chimney structure of the present embodiment, since the inner cylinder and the outer cylinder are formed in a double structure, the noise caused by the above-described fantasy pipe effect is canceled out by the noise caused by the tubular flow path from the inner cylinder and the annular flow path formed between the inner cylinder and the outer cylinder, respectively, at frequencies, thereby greatly reducing the noise without affecting the surrounding environment.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. (embodiment 1)

FIG. 1 is a schematic explanatory view showing a chimney structure according to embodiment 1.

In the figure, 1 is a combustion chamber of a garbage incinerator, and is divided into a 1 st combustion chamber 11, a 2 nd combustion chamber 12 and a 3 rd combustion chamber 13, wherein the 1 st combustion chamber 11 is used as an incinerator directly charged with a combustion object, and the 2 nd combustion chamber 12 and the 3 rd combustion chamber 13 are subjected to two-stage reburning thereafter. In each of the

combustion chambers

11, 12, and 13, the combustion temperature is controlled to suppress the generation of harmful substances as much as possible. In the figure, 14 denotes a combustion device provided in each of the

combustion chambers

11, 12, and 13, and 15 denotes a passage communicating the 1 st combustion chamber 11 with the2 nd combustion chamber 12.

Reference numeral 3 denotes a chimney as an essential part of the present invention, and a porous laminate 4 is disposed in a tube body 30 forming a combustion gas flow path R, the tube body having a base end 30a communicating with the combustion chamber 1 and an exhaust port 30b provided at a tip end thereof.

That is, the base end 30a of the pipe 30 is connected to the 3 rd combustion chamber 13, the pipe 30 extends directly upward, and the discharge port 30b is spaced from the combustion device 14 of the 3 rd combustion chamber 13 by a distance h.

A plurality of porous stacks 4 are disposed at appropriate intervals inside the tube 30, and the combustion gas discharged from the combustion chamber 1 flows through the tube 30 through the stacks 4.

Therefore, by the fantasy duct effect produced by the stack 4, the exhaust gas rising at a high temperature from the lower portion of the tube body 30 is reduced to near room temperature in the vicinity of the discharge port 30b, and thus secondary generation of dioxin and the like can be prevented.

The laminated member 4 may be formed in a shape that can be disposed in the stack 3 by using a porous ceramic used as an exhaust gas treatment catalyst in an automobile exhaust pipe.

The number and the position of the stacked members 4 to be arranged can be determined by experiments, and in this embodiment, 3 stacked members 4 are arranged at intervals of h/4 from the position of the combustion device 14 of the 3 rd combustion chamber 13.

The above chimney structure can be used in large-sized garbage incinerators, small-sized incinerators for schools and households, and can be used as a chimney which can suppress the generation of dioxin and is favorable for environmental protection when used in small-sized incinerators.

The tube 30 is vertical and may be slightly inclined if it is a small chimney. (embodiment 2)

FIG. 2 is a schematic explanatory view showing a chimney structure according to embodiment 2. In the figure, 1 is a combustion chamber of a garbage incinerator, and a desulfurizer 2 is attached. The combustion chamber 1 of the present embodiment can perform high-temperature combustion at 1250 to 1450 ℃ in order to suppress the generation of dioxin and the like. In addition, a sub-combustor (not shown) may be provided, and combustion at about 800 ℃ may be performed in the combustor 1, and high-temperature combustion may be performed in the sub-combustor to form incineration ash and fly ash into slag.

In the above structure, the present embodiment is characterized in that the tubular body 30 of the chimney 3 is extended upward and bent downward in the middle to form an inverted U-shape, and the porous laminate 4 is disposed in the middle of each of the 1 st vertical portion 31 and the 2 nd vertical portion 32 of the inverted U-shaped tubular body 30.

The exhaust port 30b near the floor surface communicates with an exhaust gas treatment device described later. In the figure, 31 is the 1 st vertical portion, 32 is the 2 nd vertical portion, and 33 is the curved portion. In the present embodiment, the height of the inverted U-shaped portion of the chimney 3 is about 15 m.

The optimal position of each laminate 4 can be determined by experiment, and in the present embodiment, the height position H of the laminate 4 disposed in the 1 st vertical portion 31 is about 3 to 8m from the base end 30 a. The height position D of the stacked member 4 disposed in the 2 nd vertical portion 32 is about 3 to 8m from the upper end of the bent portion 33.

A filter 5 for removing dust is disposed downstream of the stack 4 in the 2 nd vertical portion 32. The arrangement position and the number of the filters 5 can be determined as appropriate, and are not particularly limited in the present embodiment.

With the above-described structure of the chimney, the combustion gas discharged from the combustion chamber 1 passes through the stack 4 and the filter 5 and the inside of the inverted U-shaped pipe body 30, and the fantasy pipe effect produced by the stack 4 can be reduced to substantially normal temperature. Thus, the temperature of the exhaust gas in the exhaust gas treatment device inlet is lowered, and secondary generation of dioxin in the exhaust gas treatment device can be prevented.

Further, the exhaust gas is subjected to primary treatment for removing coal and dust by the stack 4 and the filter 5, and the exhaust gas subjected to the primary treatment flows into the exhaust gas treatment device, thereby reducing the treatment load on the exhaust gas treatment device. In addition, if silver or silver oxide is supported on the laminate 4, the primary treatment effect of the exhaust gas can be further improved.

Next, the structure of the exhaust gas treatment device in this embodiment will be described.

The purpose of the exhaust gas treatment device is to remove harmful substances such as dioxins and to prevent carbon dioxide (CO) from warming the earth₂) And is exhausted to the atmosphere. Therefore, the exhaust gas treatment device functions as a gas generation unit 6, and the gas generation unit 6 generates methane gas by a reduction reaction of carbon dioxide using water using a photocatalyst.

In the present embodiment, the gas generator 6 includes a combustion gas container 60, a water tank 61 communicating with the combustion gas container 60, and a methane gas purification chamber 62 communicating with the water tank 61. At the same time, a photocatalyst 64 having palladium supported on the surface of titanium oxide is dispersed in the water tank 61. Reference numeral 62a denotes a methane gas lead-out portion.

The photocatalyst 63 is a semiconductor photocatalyst which is a solid capable of accumulating many electrons, and as shown in the following formula, water can be used as a reducing agent to efficiently reduce carbon dioxide and improve the efficiency of methane gas generation. The following formula represents a reaction formula for producing methane gas by reducing carbon dioxide.

The produced methane gas can be effectively used as energy for power generation and heating.

As described above, according to the present embodiment, carbon dioxide is not discharged in a large amount into the atmosphere, and thus contributes greatly to prevention of global warming, and methane gas is used instead of carbon dioxide generated by combustion, and thus can be effectively used as an external energy source such as an electric power source and a heat source.

Fig. 3 shows a modification of the exhaust gas treatment device for obtaining methane gas from the generated carbon dioxide.

I.e. in the exhaust treatment stream connected in communication with the stack 3Way S is provided with and accommodates V₂O₅-TiO₂ A catalyst chamber 65 for NOx decomposition catalyst, and a liquefaction tank T1, a reaction tank T2, and a gas tank T3 arranged in series downstream thereof. The liquefaction tank T1 liquefies and separates carbon dioxide from nitrogen. Reaction tankT2 gasifies the carbon dioxide and reacts with hydrogen. The gas tank T3 accommodates methane gas generated by the reaction of carbon dioxide and hydrogen. V1 is a drain valve.

In the reaction tank T2, Fe, Ru and Ni-Al are added₂O₃Si, etc. as a catalyst, and methane gas is produced by the following reaction.

The temperature and pressure in the reaction tank T2 can be appropriately determined depending on the catalyst used.

Reference numeral 66 denotes a reduction tank 66 which stores an aqueous urea solution as a reducing agent and sprays the aqueous urea solution into the exhaust treatment passage S through a valve 66V, and the reduction tank 66 is disposed on the upstream side of the catalyst chamber 65. Reference numeral 67 denotes a nitrogen separation tank connected to the liquefaction tank T1. 67V is a liquid nitrogen bleed valve. Numeral 68 denotes a hydrogen generator which communicates with the reaction tank T2 through a valve V2. In the hydrogen generating unit 68, water is decomposed, and hydrogen is obtained by the reaction of water and a metal.

The temperature of the flow path and the liquefaction tank T1 on the downstream side of the catalyst chamber 65 was 31 ℃ or lower, and the pressure was maintained at 72.8 atm.

In the above configuration, a blower (not shown) for forcibly introducing the exhaust gas from the chimney 3 into the exhaust treatment passage S is provided at the connection portion between the chimney 3 and the exhaust treatment passage S. (embodiment 3)

Next, embodiment 3 of the present invention will be described with reference to fig. 4. In this embodiment, the structure of the stack 3 is the same as that of embodiment 2, but the exhaust gas treatment device may be used to treat carbon dioxide contained in the exhaust gas as calcium carbonate (CaCO)₃) And (6) recovering.

That is, as shown in fig. 4, the exhaust gas treatment device of the present embodiment is a carbon dioxide recovery tank 7, and the carbon dioxide recovery tank 7 contains a treatment liquid 70 in which calcium hydroxide (hydrated lime) is dissolved, and the carbon dioxide contained in the exhaust gas is made calcium carbonate (CaCO)₃) And (6) recovering.

As shown in the following formula, carbon dioxide reacts with calcium hydroxide to form calcium carbonate and water.

Calcium carbonate acts as a reservoir of carbon dioxide on earth, existing in its natural stable form as calcite.

Therefore, according to the present embodiment, carbon dioxide generated by combustion is recovered in a stable state without being discharged to the atmosphere.

Since the desulfurization device 2 is additionally provided in the combustion chamber 1, the calcium carbonate can be reused as an absorbent for the desulfurization device 2. When calcium carbonate is used, it reacts with SOx in the exhaust gas to obtain gypsum as a by-product.

It is also known that when calcium hydroxide is dissolved in water, it is preferably at a low temperature, and in this embodiment, since the exhaust gas temperature is greatly lowered by the chimney 3 by the magic tube effect, the amount of calcium hydroxide dissolved in the treatment liquid 70 can be secured without raising the temperature of the treatment liquid 70 in the carbon dioxide recovery tank 7.

Further, it is preferable that the inside of the carbon dioxide collecting tank 7 is kept at a negative pressure so that the exhaust gas from the combustion chamber 1 passing through the inverted U-shaped pipe body 30 can be efficiently sucked even without a blower device. In the figure, P is a vacuum pump for forming a negative pressure in the carbon dioxide recovery tank 7, and is provided in the middle of the exhaust pipe 71 extending from the ceiling wall of the carbon dioxide recovery tank 7. Reference numeral 72 denotes a calcium carbonate outlet formed in the bottom wall of the carbon dioxide recovery tank 7. Reference numeral 73 denotes an on-off valve communicating with the outlet 72.

In fig. 4, as indicated by a chain line a, a plurality of carbon dioxide recovery tanks 7 may be provided in series according to the amount of treatment. In this case, the tip of the exhaust pipe 71 may be extended to be deeply inserted into the 2 nd groove 7'.

As shown in fig. 4, a dioxin treatment chamber 8 using supercritical water may be provided downstream of the combustion chamber 1.

The supercritical water is a critical state of liquid and gas by applying a predetermined pressure and a predetermined temperature to water. In this state, when a gas containing dioxin is added, the gas is decomposed and detoxified.

As described above, the chimney structure according to embodiment 3 of the present invention does not emit a large amount of carbon dioxide into the atmosphere, and thus contributes significantly to prevention of global warming, as in

embodiments

1 and 2.

Fig. 5 shows a modification of the exhaust gas treatment device in embodiment 3.

That is, the structure shown in fig. 3 is used between the chimney 3 and the carbon dioxide recovery tank 7, and carbon dioxide is separated from the exhaust gas, introduced into the treatment liquid 70, and recovered as stable calcium carbonate. Therefore, the nitrogen component and the like in the exhaust gas are not introduced into the carbon dioxide recovery tank 7, and the carbon dioxide can be efficiently converted into calcium carbonate. (embodiment 4)

Next, embodiment 4 of the present invention will be described with reference to fig. 6. This 4 th embodiment is characterized by the configuration of the chimney 3. In embodiment 1, the chimney is a single upright shape, and in

embodiments

2 and 3, the inverted U-shaped pipe body 30 is formed in an upright shape having a double-tube structure. The structure of the exhaust gas treatment device connected to the stack 3 may be any of the forms shown in the above-described

embodiments

2 and 3, or may be a structure described later or another structure.

The combustion chamber 1 in the present embodiment is divided into a 1 st combustion chamber 11, a 2 nd combustion chamber 12, and a 3 rd combustion chamber 13 as in the 1 st embodiment. The 1 st combustion chamber 11 is an incinerator into which a material to be burned is directly charged, and the 2 nd and 3 rd combustion chambers are re-combusted in two stages thereafter.

The chimney 3 of the present embodiment connected to the combustion chamber 1 is constructed as follows. That is, the upper end 35a of the inner cylinder 35 is open, the base end 35b of the inner cylinder 35 communicates with the combustion chamber 1, the inner cylinder 35 is enclosed in the outer cylinder 36, the upper end of the outer cylinder 36 is closed, the exhaust port 36a is formed in the middle of the cylinder, the tubular flow path R1 inside the inner cylinder 35 communicates with the annular flow path R2 between the inner cylinder 35 and the outer cylinder 36 to form the combustion gas flow path R, and the porous laminated member 4 is disposed in the combustion gas flow path R.

The exhaust port 36a formed in the outer cylinder 36 is connected to the exhaust gas treatment device described in

embodiments

1 and 2. Reference numeral 36b denotes a closed upper end of the outercylinder 36. Reference numeral 5 denotes a filter disposed downstream of the stack 4.

The shape of the laminate 4 and the filter 5 is formed into a cylindrical shape or a ring shape conforming to the tubular flow path R1 and the annular flow path R2, respectively.

With the above-described structure, in the present embodiment, the stack 4 is disposed in the combustion gas flow path R, a fantasy pipe effect accompanying heat transfer is produced, the chimney exit temperature, that is, the temperature from the exhaust port 36a of the outer cylinder 36 to the downstream side can be greatly reduced, and even if the exhaust port 36a is located at a low position close to the ground, there is no adverse effect of soot or high-temperature gas.

Further, unlike the first and second embodiments, the chimney 3 is not bent, but the inner cylinder 35 and the outer cylinder 36 have a double upright structure, so that the length of the combustion gas flow path R required for the stack 4 to reduce the gas temperature can be ensured, and the height of the chimney 3 can be reduced by approximately half of the length of the flow path R.

In addition, since the device is upright, a small installation space is required.

Further, since the chimney 3 is formed of the double pipe structure by the inner cylindrical body 35 and the outer cylindrical body 36, a silencing effect is obtained.

That is, since the double pipe structure is adopted, the noises generated by the respective pipe-shaped flow paths and the annular flow path interfere with each other and the frequencies thereof cancel each other out, thereby greatly reducing the noises. Therefore, the chimney structure of the present embodiment has no influence on the surrounding environment.

The number and the arrangement interval of the stacks 4 can be appropriately set according to the length of the combustion gas flow path R. By determining the number and arrangement of the stacks 4, the height position of the exhaust port 36a communicating with the exhaust gas treatment device can be freely set. Therefore, even when a facility such as an exhaust gas treatment device is constructed after the installation of the stack 3, the exhaust port 36a can be provided at an optimum position in consideration of the installation conditions of the facility and the installation conditions of the combustion chamber 1.

Therefore, the chimney structure of the present embodiment can reduce the height of the chimney 3, save the installation space, suppress the construction cost, and reduce the noise.

In this embodiment, as in

embodiments

1 and 2, the exhaust gas treatment device is connected in communication therewith, and carbon dioxide that warms the earth can be prevented from being released into the atmosphere.

In addition to the above-described forms, the exhaust gas treatment device may have a structure shown in fig. 7 and 8.

That is, the exhaust gas treatment devices shown in fig. 7 and 8 can produce methanol from carbon dioxide in the exhaust gas.

The apparatus shown in FIG. 7 basically has the structure shown in FIG. 3, and V is accommodated in the exhaust gas treatment passage S₂O₅-TiO₂ A catalyst chamber 65 for NOx decomposition catalyst, and a liquefaction tank T1, a reaction tank T2, and a methanol tank T4 arranged in series downstream thereof. The liquefaction tank T1 liquefies and separates carbon dioxide from nitrogen. The reaction tank T2 gasifies the carbon dioxide and then reacts with hydrogen. The methanol tank T4 contains methanol produced by the reaction of carbon dioxide and hydrogen. V3 is a methanol take-off valve.

With the above-described structure, methane gas is generated in the reaction tank T2 by the reaction described below.

Of course, an appropriate catalyst is used, and the temperature and pressure in the reaction tank T2 are appropriately set according to the catalyst used.

The apparatus shown in FIG. 8 is configured to further separate carbon dioxide generated by the apparatus shown in FIG. 7 into carbon monoxide and water, and to react the carbon monoxide with hydrogen to obtain methanol.

I.e. by To obtain methanol. In this case, too, an appropriate catalyst is selected and the temperature and pressure conditions are set appropriately. In the figure, T5 denotes a carbon monoxide tank, and is connected to the hydrogen generator 68 through a valve V2'.(embodiment 5)

Fig. 9 shows a device for obtaining pure carbon by using an exhaust gas treatment device, and basically has the same structure as that shown in fig. 3. Reference numeral B denotes a blower for forcibly drawing the exhaust gas from the stack 3 into the exhaust treatment passage S.

That is, V is accommodated in the exhaust gas treatment passage S connected to the chimney 3₂O₅-TiO₂ A catalyst chamber 65 for NOx decomposition catalyst, and a liquefaction tank T1, a reaction tank T2, and a carbon tank T6 arranged in series downstream thereof. The liquefaction tank T1 liquefies and separates carbon dioxide from nitrogen. The reaction tank T2 gasifies the carbon dioxide and then reacts with hydrogen. The carbon tank T6 contains carbon generated by the reaction of carbon dioxide and hydrogen.

By using To obtain carbon. In this case, too, an appropriate catalyst is selected and the temperature and pressure conditions are appropriately set.

In the present embodiment, the chimney 3 has a double pipe structure including the inner cylindrical body 35 and the outer cylindrical body 36, as in embodiment 4, and a cooling circuit F is provided as a stack cooling mechanism for forcibly cooling the stack 4.

As shown in fig. 10, the cooling circuit F includes a cooling tank F1 and a pipe section F2 constituting a circulation flow path. The cooling tank F1 stores cooling water and is equipped with a pump capable of forced circulation. The pipe used in the pipe distribution portion F2 is preferably a member having high heat conductivity, and in this embodiment, a copper pipe is used.

The middle of the pipe portion F2 is formed in a spiral shape so as to contact the surface of the laminated member 4. F2' is the contact portion.

Further, a member having high thermal conductivity such as a copper plate may be interposed between the contact portion F2' and the laminated member 4.

In the present embodiment, the cooling tank F1 is provided outside the chimney 3, but the cooling tank F1 may be configured to have sufficient heat insulation and be disposed between the inner cylinder 35 and the outer cylinder 36, that is, inside the chimney 3, in order to improve the appearance.

Although the embodiments of the present invention have been described above, an exhaust gas treatment device and the like are not necessarily provided, and the configuration thereof is not limited to the above embodiments.

In addition, the cooling circuit F that forcibly cools the stack 4 is also applicable to the 1 st to 4 th stacks described above

Examples are given.

Industrial applicability

The present invention is implemented in the above-described embodiment, and has the following effects.

(1) The chimney structure according to claim 1, wherein a porous laminate is disposed in a pipe body of a combustion gas flow path formed by providing a base end communicating with the combustion chamber and a tip end with an exhaust port. Therefore, by providing the stack, a fantasy pipe effect accompanying heat transfer is produced, the chimney exit temperature can be greatly reduced, and secondary generation of dioxin can be prevented. Therefore, the chimney can be used in a small-sized incinerator or the like, and the chimney height can be reduced and the construction cost can be suppressed even in a large-sized incinerator.

(2) The chimney structure according to claim 2, wherein the pipe body is bent in an inverted U-shape, and a porous laminate is disposed in a combustion gas flow path formed in the pipe body. Therefore, the height of the chimney can be further reduced, the construction cost can be suppressed, and the fantasy pipe effect accompanying heat transfer can be obtained by arranging the laminated member even if the exhaust port is close to the ground.

(3) A chimney structure according to claim 3, wherein an upper end of the inner cylinder is open, a base end of the inner cylinder communicates with the combustion chamber, the inner cylinder is enclosed in the outer cylinder, an upper end of the outer cylinder is closed, an exhaust port is formed in a middle portion of the outer cylinder, a tubular flow path inside the inner cylinder communicates with an annular flow path between the inner cylinder and the outer cylinder to form a combustion gas flow path, and a porous laminated member is disposed in the combustion gas flow path, so that the chimney can secure a necessary length of the exhaust gas flow path, and has a double structure with a reduced height by half, thereby reducing a height, saving a space, and suppressing construction costs. Further, by providing the stack, a fantasy pipe effect accompanying heat transfer is obtained, and the chimney outlet temperature can be greatly reduced, so that even if the exhaust port is located at a low position close to the floor, there is no adverse effect of soot and high-temperature gas. Further, since the double pipe structure is adopted, noise due to the fantasy pipe effect can be eliminated.

(4) The chimney structure according to claim 4, wherein a filter is disposed in the combustion gas flow path. Thus, soot and dust may be absorbed and clean exhaust gas may be discharged.

(5) The chimney structure according to claim 5, wherein the exhaust port is connected to the exhaust gas treatment device. Therefore, the exhaust gas is clean and does not cause environmental pollution.

(6) The chimney structure according to claim 6, wherein a blower is provided at the exhaust port. Therefore, the exhaust gas of the combustion chamber can be efficiently guided to the exhaust gas treatment device.

(7) The chimney construction of claim 7, wherein the stack is formed from a porous ceramic. Thus, existing materials can be utilized as a laminate, which is easily available and further enhances the illusive pipe effect.

(8) The chimney structure according to claim 8, wherein the exhaust gas treatment device is a gas generation unit, and the gas generation unit generates methane gas by generating a carbon dioxide reduction reaction with water using a photocatalyst. Therefore, carbon dioxide is converted into methane gas without being released into the atmosphere, and thus can be used as an external energy source such as an electric power source and a heat source.

(9) The chimney structure according to claim 9, wherein the gas generating section comprises a combustion gas containing chamber, a water tank section communicating with the combustion gas containing chamber, and a methane gas purifying chamber communicating with the water tank section, and a photocatalyst having palladium supported on a titanium oxide surface is dispersed in the water tank section. Thus, water can be used as a reducing agent, and a semiconductor photocatalyst, which is a solid capable of accumulating many electrons, is used, whereby carbon dioxide can be efficiently reduced, and the efficiency of methane gas generation can be improved.

(10) The chimney structure according to claim 10, wherein the exhaust gas treatment device is a carbon dioxide recovery tank which contains a treatment liquid in which calcium hydroxide is dissolved and which is capable of recovering carbon dioxide contained in the combustion gas as calcium carbonate. Therefore, carbon dioxide generated by combustion can be recovered in a stable state.

(11) The chimney structure according to claim 11, wherein the carbon dioxide recovery tank is maintained at a negative pressure. Therefore, the combustion gas can be efficiently introduced into the carbon dioxide recovery tank.

(12) The chimney structure according to claim 12, wherein the exhaust gas treatment device separates the exhaust gas into nitrogen gas and carbon dioxide gas by a catalyst for decomposing NOx, and reacts the separated carbon dioxide gas with hydrogen generated by the hydrogen generation device to generate methanol. Therefore, carbon dioxide is converted into methanol without being discharged into the atmosphere, and can be effectively used as an external energy source such as an electric power source and a heat source.

(13) The chimney structure according to claim 13, wherein the exhaust gas treatment device separates the exhaust gas into nitrogen gas and carbon dioxide by a catalyst for decomposing NOx, and reacts the separated carbon dioxide with hydrogen generated by the hydrogen generation device to generate carbon. Thus, carbon dioxide is not emitted to the atmosphere, and carbon as a pure resource may be used instead.

(14) The chimney structure according to claim 14, wherein a cooling circuit is provided for cooling the surface of the stack. Therefore, the exhaust gas temperature can be effectively lowered.

Claims

1. The chimney structure is characterized in that a porous laminated body is arranged in a pipe body of a combustion gas flow path formed by a base end communicated with a combustion chamber and a front end provided with an exhaust port.

2. A chimney structure according to claim 1, wherein the pipe body is bent in an inverted U-shape, and a porous laminate is disposed in a combustion gas flow path formed in the pipe body.

3. The chimney structure is characterized in that the upper end of an inner cylinder is open, the base end of the inner cylinder is communicated with a combustion chamber, an outer cylinder encloses the inner cylinder, the upper end of the outer cylinder is closed, an exhaust port is formed in the middle of the outer cylinder, a tubular flow passage in the inner cylinder is communicated with an annular flow passage between the inner cylinder and the outer cylinder to form a combustion gas flow passage, and a porous laminated member is arranged in the combustion gas flow passage.

4. A chimney structure according to any one of claims 1 to 3, wherein a filter is provided in the combustion gas flow path.

5. A chimney construction according to any of claims 1 to 4, characterised in that the exhaust port is connected in communication with an exhaust gas treatment device.

6. A chimney construction according to any of claims 1 to 5, characterised in that a blower is provided at the exhaust.

7. The chimney construction of any of claims 1 to 6, wherein the laminate is formed from a porous ceramic.

8. The chimney structure according to any one of claims 5 to 7, wherein the exhaust gas treatment device is a gas generation unit, and the gas generation unit generates methane gas by generating a carbon dioxide reduction reaction with water of the photocatalyst.

9. The chimney structure according to claim 8, wherein the gas generating section comprises a combustion gas containing chamber, a water tank section communicating with the combustion gas containing chamber, and a methane gas purifying chamber communicating with the water tank section, and a photocatalyst having palladium supported on a titanium oxide surface is dispersed in the water tank section.

10. A chimney structure according to any one of claims 5 to 7, characterized in that the exhaust gas treatment device is a carbon dioxide recovery tank which contains a treatment liquid in which calcium hydroxide is dissolved and which can recover carbon dioxide contained in combustion gas as calcium carbonate.

11. The chimney structure according to claim 10, wherein the carbon dioxide recovery tank is maintained at a negative pressure.

12. A chimney structure according to any one of claims 5 to 7, characterized in that the exhaust gas treatment device separates the exhaust gas into nitrogen gas and carbon dioxide by a NOx decomposition catalyst, and reacts the separated carbon dioxide with hydrogen generated from the hydrogen generation device to generate methanol.

13. A chimney structure according to any one of claims 5 to 7, characterized in that the exhaust gas treatment device separates the exhaust gas into nitrogen gas and carbon dioxide by a NOx decomposition catalyst, and reacts the separated carbon dioxide with hydrogen generated from the hydrogen generation device to generate carbon.

14. A chimney construction according to any of claims 1 to 13, characterised in that there is provided a cooling circuit for cooling the surface of the stack.