JP3793956B2 - Method and apparatus for cleaning chimneys and flues - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for purifying chimneys and flues contaminated by dioxins.
[0002]
[Prior art]
In recent years, dioxins accumulated in smoke exhaust facilities such as chimneys and flues have become a problem. In other words, when disassembling chimneys and flues, dioxins must be detoxified and landfilled, and if contaminated smoke exhaust facilities are used as they are, the accumulated dioxins are mixed into the smoke. However, there is a possibility of leaking outside.
[0003]
Generally, asbestos and bricks for improving heat resistance are arranged inside the chimney, etc., but dioxins accumulated in this part have been removed by cutting part of the lining conventionally. It was.
[0004]
[Problems to be solved by the invention]
However, with regard to removing a part of the lining in this way, (1) dioxins may volatilize due to the generation of dust accompanying cutting, and (2) occur during cutting. Dioxins may volatilize due to heat generated and may contaminate the surrounding area. (3) When water is sprayed to prevent dust from being scattered during cutting, sludge or water may leak out. There were problems such as the possibility of contaminating the surroundings.
[0005]
Various methods for dioxins decomposition, including the technology disclosed in JP-A-5-104073, have been proposed, and the superiority of the method based on thermal decomposition has been confirmed. Among these methods, the method using a vertical furnace is said to be able to decompose dioxins relatively easily and at low cost. The problem is that there is no safe way to collect contaminated parts.
[0006]
The present invention has been made in view of the above circumstances, and in removing and purifying the chimney and the dioxins in the flue, the chimney is less likely to contaminate the surroundings and can be safely operated. -It aims at providing the purification method and apparatus in a flue.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present invention employs the following means.
That is, in the method for purifying a chimney or flue according to claim 1 , the chimney or the inlet and outlet of the flue are sealed to form a closed space in the chimney or the flue, and the temperature in the closed space is changed to the temperature in the closed space. A method for purifying a chimney or flue that raises the temperature to a temperature at which dioxins present in the chimney or flue are decomposed ,
When raising the temperature in the chimney or flue, while keeping the oxygen concentration in the enclosed space at 2% or less, nitrogen gas kept at 350 to 400 ° C. is introduced, and the nitrogen gas is chemically changed. The decomposition gas generated by doing so is sucked from the enclosed space.
[0010]
The method for purifying a chimney / chimney according to claim 2 forms a closed space in the chimney or flue by sealing an inlet and an outlet of the chimney or the flue, and the temperature in the closed space is set to the chimney or the flue. A method for purifying chimneys and flues that raises the temperature to the temperature at which dioxins present in the flues are decomposed ,
When raising the temperature in the chimney or the flue, heated hydrogen gas is flowed into the closed space, the temperature in the closed space is heated to 850 ° C., and the hydrogen gas is chemically changed. The generated decomposed gas is sucked from the enclosed space.
[0011]
The chimney / flue purification method according to claim 3 , wherein the chimney or the flue inlet and outlet are sealed to form a closed space in the chimney or the flue, and the temperature in the closed space is set to the chimney or the flue. A method for purifying chimneys and flues that raises the temperature to the temperature at which dioxins present in the flues are decomposed ,
When raising the temperature in the chimney or the flue, heated air is introduced into the closed space, the temperature in the closed space is heated to 850 ° C. or more, and the air is chemically changed. The decomposition gas is sucked from the enclosed space.
[0012]
In the inventions of these first to third aspects, the chimney / smoke can be decomposed in situ while taking advantage of the sealing and heat resistance of the chimney / smoke, and the chimney / smoke can be satisfactorily processed. Dioxins deposited in the road can be decomposed.
[0013]
The chimney / flue purification method according to claim 4 is the chimney / flue purification method according to any one of claims 1 to 3 ,
In raising the temperature in the chimney or the flue, a part of the chimney or the flue wall is sampled in advance, and the sample is used to measure the thickness dimension of the contaminated area due to the dioxins in the wall. When a plurality of temperature sensors are arranged in the direction in which the wall portion has a thickness inside the hole formed by collecting the sample, and the temperature in the chimney or the flue is raised In addition, it is characterized in that the temperature sensor confirms that the temperature in at least the contaminated area in the chimney or the flue has increased to a temperature at which dioxins are decomposed.
[0014]
With such a configuration, it is possible to determine the contaminated area of dioxins in the chimney / flue and reliably realize a temperature at which the dioxins are thermally decomposed in the contaminated area.
[0015]
The purification device for a chimney / flue according to claim 5 is a device for purifying the inside of the chimney / flue,
A heated gas generator for generating heated gas;
A cracked gas treatment device for treating a cracked gas produced by the chemical reaction of the heated gas with dioxins;
A supply pipe connecting the heated gas generator and the chimney or flue;
Comprising a suction pipe connecting the chimney or the flue and the cracked gas treatment device,
The entrance and exit of the chimney or flue are each sealed by a sealing jig,
Either one of the sealing jigs is provided with a first communication hole that communicates the inside or outside of the chimney or the flue, and either one or the other of the sealing jigs is connected to the inside or outside of the chimney or the flue. A second communication hole for communication is provided;
The supply pipe has one end connected to the heated gas generator and the other end inserted into the first communication hole.
One end of the suction pipe is inserted into the second communication hole, and the other end is connected to the cracked gas processing apparatus.
[0016]
With such a configuration, the heated gas generated by the heated gas generator is supplied to the space inside the chimney / flue sealed by the sealing jig, and the decomposition gas generated in the chimney / flue is sucked in. It can be decomposed in a cracked gas treatment device.
[0017]
The purification device for a chimney / flue according to claim 6 is the purification device for a chimney / flue according to claim 5 ,
One end is connected to one end of the supply pipe, and the other end includes a heated gas transfer pipe arranged to reach the upper part of the chimney or the flue,
One end of the suction pipe is arranged at the lower part in the chimney or the flue.
[0018]
With this configuration, when the specific gravity of the supplied heated gas is smaller than the specific gravity of the cracked gas formed by the chemical reaction between the heated gas and dioxins, the gas can be circulated well in the chimney / flue. It can be performed.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram schematically showing an embodiment of the present invention. In the figure, reference numeral 1 indicates a purification device.
[0020]
This purification device 1 is applied to a chimney 2, and includes a heating gas generation device 3 that generates a heating gas, and a supply pipe 4 that supplies the heating gas from the heating gas generation device 3 into the chimney 2. A suction pipe 5 for sucking the decomposition gas generated by the chemical reaction of the heated gas supplied into the chimney 2 with the dioxins in the chimney 2 from the chimney 2, and a decomposition connected to the suction pipe 5 The gas processing apparatus 6 is provided.
[0021]
Further, an upper sealing jig 10 and a lower sealing jig 11 are respectively attached to the smoke exhaust port 8 located in the upper part 2a of the chimney 2 and the smoke sending port 9 located in the lower part 2b. Among these, the lower sealing jig 11 is provided with first and second communication holes 12 and 13 as shown in an enlarged view in FIG. 2, and the end 4a of the supply pipe 4 and the suction pipe 5 end portions 5 a are inserted into the first and second communication holes 12 and 13. Further, one end 14 a of the heated gas transfer pipe 14 is connected to the end 4 a of the supply pipe 4. The heated gas transfer pipe 14 is provided inside the chimney 2 and is disposed so that the other end 14b reaches the upper part 2a of the chimney 2 as shown in FIG. .
[0022]
In addition, the chimney 2 to which the purification apparatus 1 is applied has a configuration in which a lining material 16 made of asbestos is arranged inside the wall portion 2c, as shown in an enlarged view in FIG.
[0023]
Next, a purification method in the chimney 2 using the purification device 1 will be described.
First, the purification device 1 is attached to the chimney 2. For this purpose, a heated gas transfer pipe 14 is arranged inside the chimney 2, and the smoke outlet 8 of the chimney 2 is sealed by the upper sealing jig 10.
[0024]
Subsequently, a lower sealing jig 11 is arranged at the smoke outlet 9 of the chimney 2. At this time, the end 4 a of the supply pipe 4 is attached to the first communication hole 12 of the lower sealing jig 11. Further, the end 4 a of the supply pipe 4 is connected to the one end 14 a of the heated gas transfer pipe 14. Further, the end portion 5 a of the suction pipe 5 is attached to the second communication hole 13 of the lower sealing jig 11. Thereby, the inlet and outlet of the chimney 2 are sealed, and a closed space S (see FIG. 1) is formed inside the chimney 2. Further, the supply pipe 4 and the suction pipe 5 are connected to the heated gas generation device 3 and the cracked gas processing device 6, respectively.
[0025]
Moreover, while performing these operations, as shown in FIG. 4, a part of the wall 2c of the chimney 2 is cut out and collected. A part of the collected wall 2c is used as a sample for specifying the thickness dimension of the contaminated area P (see FIG. 4) of dioxins in the chimney 2. This is because in the chimney 2, not only the lining material 16 but also part of the wall 2 c is likely to be contaminated by dioxins in the flue gas. This is because it is necessary to identify and apply appropriate treatment to all parts of the contaminated area P. Here, of the collected part of the wall 2c, the part contaminated by dioxins is the wall part. By specifying the dimension that 2c has in the direction having the thickness (the x direction in FIG. 4), the thickness dimension of the contaminated region P is estimated.
[0026]
Next, as shown in FIG. 5, thermocouples (temperature sensors) 18, 18,... Are arranged inside the hole 17 formed by removing a part of the wall 2 c. These thermocouples 18, 18,... Are arranged so as to be spaced apart from each other in the direction in which the wall 2c of the chimney 2 has a thickness (the x direction in FIG. 5), and at least on the outermost side when viewed from the inside of the chimney 2. The located thermocouple 18 is provided so as to be located outside the contaminated region P. These thermocouples 18, 18,... Are connected to a control device (not shown) for controlling the heated gas generator 3.
[0027]
Then, the heated gas generator 3 is driven, and hot air is sent into the chimney 2 through the supply pipe 4 and the heated gas transfer pipe 14. In this case, the temperature detected from at least the innermost thermocouple 18, 18,... Arranged outside the contaminated area P when viewed from the inside of the chimney 2 is 850 ° C. or more. Thus, the temperature of the hot air discharged from the heated gas generator 3 is adjusted.
[0028]
By sending the hot air into the chimney 2 in this way, the hot air and the dioxins accumulated inside the chimney 2 chemically react, and the dioxins are thermally decomposed and a decomposition gas is formed. Since the specific gravity of the cracked gas generated here is larger than the specific gravity of the hot air supplied into the chimney 2, the cracked gas descends inside the chimney 2 and decomposes from the lower part 2 b of the chimney 2 through the suction pipe 5. Suctioned to the gas processing device 6 side. In the cracked gas treatment device 6, the cracked gas is purified and discharged into the atmosphere by activated carbon carrying an amine compound.
The flow rate of the hot air supplied from the heated gas generator 3 is set so that the residence time of the gas in the chimney 2 is about 60 minutes.
[0029]
Further, when the amount of the decomposition products of dioxins in the cracked gas has been reduced to a negligible level, the supply of hot air is stopped and the processing operation is terminated.
[0030]
In the purification method of the chimney 2 described above, the entrance and exit of the chimney 2 is sealed to form a closed space S in the chimney 2, and the temperature in the closed space S is reduced to decompose dioxins existing in the chimney 2. Therefore, the dioxins in the chimney 2 can be decomposed in-situ using the hermeticity and heat resistance of the chimney 2. For this reason, unlike the conventional case, when removing dioxins, it is not necessary to cut a part of the lining in the chimney 2, reducing the possibility of contamination spreading around and ensuring work safety. In addition, the cost can be reduced.
[0031]
In particular, in this case, since heated air is introduced into the closed space S and the temperature in the closed space S is heated to 850 ° C. or higher, it is possible to easily and reliably decompose dioxins. is there.
[0032]
Further, in the above-described method for purifying the chimney 2, in order to raise the temperature in the chimney 2, a part of the wall 2c of the chimney 2 is sampled in advance as a sample, and the contamination region P in the wall 2c is obtained by this sample. , And a plurality of thermocouples 18, 18,... Are arranged in a direction in which the wall portion 2c has a thickness in the hole 17 formed by collecting the sample. Since the pair 18, 18,... Is to check whether or not the temperature in the contaminated area P is 850 ° C. or higher, the contaminated area P can be reliably identified and the contaminated area. It can be easily confirmed that all the parts in P have risen to a temperature at which dioxins are thermally decomposed, and it is possible to reliably process dioxins.
[0033]
Further, in the purification device 1 described above, the heated gas generated by the heated gas generator 3 is supplied into the closed space S, and the cracked gas generated in the chimney 2 is sucked in the cracked gas processing device 6. Because it can be decomposed, it becomes possible to use the chimney 2 as a vertical furnace for decomposing dioxins. Dioxins deposited in the chimney 2 are treated in-situ, and safe and reliable treatment of dioxins It can be performed.
[0034]
Further, in the purification device 1 described above, one end 14 a of the heated gas transfer pipe 14 is connected to the supply pipe 4, the other end 14 b is disposed inside the upper part 2 a of the chimney 2, and one end of the suction pipe 5 is further provided. Since 5a is arranged in the lower part 2b of the chimney 2, utilizing the fact that the specific gravity of the supplied heated gas is smaller than the specific gravity of the cracked gas formed by the chemical reaction between the heated gas and dioxins, Gas can be circulated well in the chimney 2 to reliably decompose dioxins.
[0035]
In the above embodiment, other configurations may be adopted without departing from the spirit of the present invention.
For example, in the above-described method for purifying the chimney 2, the nitrogen gas in which the gas supplied into the chimney 2 is maintained at 350 to 400 ° C. after the inside of the chimney 2 reaches a predetermined temperature (350 to 400 ° C.) by the supply of hot air. In addition, the inflow of nitrogen gas may be continued for a predetermined time in a state where the oxygen concentration inside the chimney 2 is 2% or less.
[0036]
Alternatively, the gas supplied into the chimney 2 may be switched to hydrogen gas maintained at 850 ° C. after the inside of the chimney 2 reaches a predetermined temperature (850 ° C.) by supplying hot air.
Further, in this case, heated hydrogen gas may be supplied into the chimney 2 from the beginning instead of heated air.
[0037]
In the purification device 1 described above, the first and second communication holes 12 and 13 to which the supply pipe 4 and the suction pipe 5 are connected are both provided to the lower sealing jig 11. One or both of these may be provided for the upper sealing jig 10.
[0038]
The application target of the purification device 1 and the purification method using the purification device 1 is not limited to the chimney, and may be applied to, for example, a flue.
[0039]
【The invention's effect】
As described above, in the chimney / flue purification method according to claims 1 to 3 , the entrance / exit of the chimney / flue is sealed to form a closed space in the chimney / flue, and the temperature in the closed space is determined. Is increased to a temperature at which dioxins present in the chimney / flues are decomposed, and the dioxins in the chimney / flues are decomposed in situ by taking advantage of the sealing and heat resistance of the chimney / flues. Can be processed. Therefore, unlike the conventional case, when removing dioxins, it is not necessary to cut part of the lining in the chimney / flue, reducing the possibility of contamination spreading around and reducing work safety. Secure and reduce costs.
[0040]
Further, in the chimney / flue purification method according to claims 1 to 3 , heated nitrogen gas, hydrogen gas, or air is allowed to flow into the closed space, and the temperature in the closed space is set to a predetermined temperature or higher. to it was decided to be heated, it is possible to decompose easily and reliably dioxins.
[0041]
In the chimney / flue purification method according to claim 4 , in order to raise the temperature in the chimney / flue, a part of the chimney / flue wall is sampled in advance, and the wall A plurality of thermocouples are arranged in a direction in which the wall portion has a thickness inside the hole formed by collecting the sample, and the thickness dimension of the contamination region P in the portion is collected. Because it is to check whether the temperature in the area contaminated with dioxins in the chimney / flues is higher than the specified temperature, the area contaminated with dioxins can be identified with certainty. The temperature at which dioxins are thermally decomposed in all portions in the region can be easily realized, and the treatment of dioxins can be reliably performed.
[0042]
In the chimney / flue purification apparatus according to claim 5 , the heated gas generated by the heated gas generator is supplied into the chimney / flue and further decomposed by sucking the decomposition gas generated in the chimney / flue. Because it can be decomposed in the gas treatment equipment, it becomes possible to use the chimney / flues as a vertical furnace for decomposing dioxins, and dioxins deposited in the chimneys / flues can be safely and reliably in situ. Can be processed.
[0043]
In the chimney / flue purification apparatus according to claim 6 , one end of the heated gas transfer pipe is connected to the supply pipe, the other end is disposed inside the upper part of the chimney / flue, and Because one end is located in the lower part of the chimney / chimney, the chimney and the chimney will be used when the specific gravity of the supplied heated gas is smaller than the specific gravity of the cracked gas formed by the chemical reaction between the heated gas and dioxins. It is possible to circulate gas well in the flue and to reliably decompose dioxins.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing an embodiment of the present invention, and is an elevational sectional view showing a situation when a purification device is applied to a chimney.
FIG. 2 is an elevational view showing the lower closing jig shown in FIG. 1 and its surroundings in an enlarged manner.
3 is an enlarged sectional view showing a wall portion of the chimney shown in FIG. 1. FIG.
FIG. 4 is an elevational sectional view showing a situation when a part of the chimney wall is sampled.
FIG. 5 is an elevational sectional view showing a situation when thermocouples are arranged inside a hole formed by sampling a part of a chimney wall.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Purification apparatus 2 Chimney 2a Upper part 2b Lower part 2c Wall part 3 Heated gas production | generation apparatus 4 Supply pipe 4a End part (other end)
5 Suction tube 5a End (one end)
6 cracking gas processing apparatus 10 upper sealing jig 11 lower sealing jig 12 first communication hole 13 second communication hole 14 heated gas transfer pipe 14a one end 14b other end 17 hole 18 thermocouple P contamination area S closed space

Claims (6)

A chimney or flue inlet and outlet are sealed to form a closed space in the chimney or flue, and the temperature in the closed space is increased to a temperature at which dioxins present in the chimney or flue are decomposed A chimney to clean the chimney
When raising the temperature in the chimney or flue, while keeping the oxygen concentration in the enclosed space at 2% or less, nitrogen gas kept at 350 to 400 ° C. is introduced, and the nitrogen gas is chemically changed. A method for purifying a chimney and a flue, wherein the cracked gas generated by the suction is sucked from the enclosed space. A chimney or flue inlet and outlet are sealed to form a closed space in the chimney or flue, and the temperature in the closed space is increased to a temperature at which dioxins present in the chimney or flue are decomposed A chimney to clean the chimney
When raising the temperature in the chimney or the flue, heated hydrogen gas is flowed into the closed space, the temperature in the closed space is heated to 850 ° C., and the hydrogen gas is chemically changed. A method for purifying a chimney and a flue, wherein the generated decomposed gas is sucked from the enclosed space. A chimney or flue inlet and outlet are sealed to form a closed space in the chimney or flue, and the temperature in the closed space is increased to a temperature at which dioxins present in the chimney or flue are decomposed A chimney to clean the chimney
When raising the temperature in the chimney or the flue, heated air is introduced into the closed space, the temperature in the closed space is heated to 850 ° C. or more, and the air is chemically changed. A method for purifying a chimney or flue, wherein the cracked gas is sucked from the enclosed space. A method for purifying a chimney / flue according to any one of claims 1 to 3 ,
In raising the temperature in the chimney or the flue, a part of the chimney or the flue wall is sampled in advance, and the sample is used to measure the thickness dimension of the contaminated area due to the dioxins in the wall. And a plurality of temperature sensors are arranged in a direction in which the wall portion has a thickness inside the hole formed by collecting the sample,
When raising the temperature in the chimney or flue, the temperature sensor confirms that the temperature in at least the contaminated area in the chimney or flue has risen to a temperature at which dioxins are decomposed. A purification method for chimneys and flues. A device for purifying the chimney and flue,
A heated gas generator for generating heated gas;
A cracked gas treatment device for treating a cracked gas produced by the chemical reaction of the heated gas with dioxins;
A supply pipe connecting the heated gas generator and the chimney or flue;
Comprising a suction pipe connecting the chimney or the flue and the cracked gas treatment device,
The entrance and exit of the chimney or flue are each sealed by a sealing jig,
Either one of the sealing jigs is provided with a first communication hole that communicates the inside or outside of the chimney or the flue, and either one or the other of the sealing jigs is connected to the inside or outside of the chimney or the flue. A second communication hole for communication is provided;
The supply pipe has one end connected to the heated gas generator and the other end inserted into the first communication hole.
One end of the suction pipe is inserted into the second communication hole, and the other end is connected to the cracked gas treatment apparatus. A purification device for a chimney or flue according to claim 5 ,
One end is connected to one end of the supply pipe, and the other end includes a heated gas transfer pipe arranged to reach the upper part of the chimney or the flue,
One end of the suction pipe is disposed in the chimney or in the lower part of the flue, and the purification device in the chimney / chimney.

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