JP6909667B2 - Combustion exhaust gas treatment device - Google Patents

Description

The present invention relates to a combustion exhaust gas treatment device, and more particularly to a combustion exhaust gas treatment device for removing mercury from the combustion exhaust gas.

Waste and coal may contain mercury. Therefore, from the viewpoint of preventing air pollution, the combustion exhaust gas generated when waste or coal is burned should be monitored for the mercury concentration contained in the combustion exhaust gas, and if the mercury concentration in the combustion exhaust gas increases abnormally. , It is necessary to detect it at an early stage and deal with it.

For example, in a waste incinerator, the waste that is incinerated on a daily basis contains almost no mercury. For this reason, the mercury concentration in the flue gas does not usually reach a problematic level without special measures against mercury. However, when waste containing mercury such as fluorescent lamps for lighting, sphygmomanometers, and thermometers is put into an incinerator and burned, the amount of mercury in the combustion exhaust gas rises sharply, which is an abnormal time. Therefore, it is sufficient to detect the mercury abnormality at an early stage and take special mercury removal measures only when the abnormality is detected to remove mercury from the combustion exhaust gas.

As a device to which such measures are taken, there is one described in Patent Document 1. In the apparatus described in Patent Document 1, a mercury continuous analyzer that detects the concentration of mercury contained in the exhaust gas flowing into the flue and a mercury concentration detected by the mercury continuous analyzer exceeds a predetermined concentration. It is provided with a means for opening a path for introducing activated carbon for mercury adsorption into the flue.

Further, in the exhaust gas flue, in addition to the activated carbon for adsorbing mercury is added to the flue, an alkaline chemical is added to react the acidic gas such as hydrogen chloride and sulfur oxide contained in the combustion exhaust gas with the alkaline chemical. Is being done.

Japanese Unexamined Patent Publication No. 9-308817

However, for example, in a waste incinerator, it takes time to detect the mercury concentration by the mercury continuous analyzer even at an abnormal time when the mercury concentration in the combustion exhaust gas suddenly rises. Therefore, there is a problem that it takes a long time to add the mercury adsorbing agent after the detection.

In addition, when the mercury concentration in the combustion exhaust gas suddenly rises abnormally, it exceeds the regulation value due to an irregular and sudden rise, so it is difficult to control the timing of adding the mercury adsorbing chemical.

Furthermore, it is stated that the alkaline chemicals added to remove acid gases such as hydrogen chloride and sulfur oxides contained in the combustion exhaust gas inhibit the mercury adsorption reaction by the mercury adsorption chemicals such as activated carbon. The inventors have found it. When the mercury adsorption reaction is inhibited, it becomes impossible to suppress the mercury concentration by that amount.

Therefore, an object of the present invention is to solve such a problem and to stably keep the mercury concentration emitted from the chimney below the regulation value.

In order to achieve this object, the combustion exhaust gas treatment device of the present invention
Combustion furnace and
A mercury removing chemical charging device for charging mercury removing chemicals into the combustion exhaust gas generated in the combustion furnace, and a mercury removing chemical charging device.
An alkaline chemical charging device that charges alkaline chemicals into the combustion exhaust gas generated in the combustion furnace, and an alkaline chemical charging device.
A control device that controls the amount of mercury chemicals charged into the combustion exhaust gas by the mercury removing chemical charging device, and a control device that controls the amount of alkaline chemicals charged into the combustion exhaust gas by the alkaline chemical charging device.
A dust collector for collecting and removing mercury-containing fly ash in combustion exhaust gas or a cleaning device for cleaning and removing mercury components in combustion exhaust gas.
A mercury analyzer for detecting the mercury concentration in the combustion exhaust gas, which is provided at a position upstream of the dust collector or the cleaning device in the emission path of the combustion exhaust gas, and
With
When the mercury concentration in the flue gas detected by the mercury analyzer becomes abnormally high, the control device measures the amount of the alkaline drug input by the alkaline agent input device to the combustion. It is characterized in that the mercury concentration in the exhaust gas is reduced as compared with the amount of the alkaline chemical input when the concentration is normal.

According to the present invention, it is preferable that the device for charging the mercury removing agent is a device for charging a dry mercury removing agent into the combustion exhaust gas.

Further, according to the present invention, it is preferable that the mercury removing chemical charging device is a device in which a wet mercury removing chemical is added to the cleaning water for the cleaning device and charged into the combustion exhaust gas.

According to the combustion exhaust gas treatment device of the present invention, when the mercury concentration in the combustion exhaust gas increases as compared with normal times, the amount of the alkaline chemical input by the alkaline chemical input device at that time is set in the combustion exhaust gas. Since the amount of alkaline chemicals is reduced compared to the amount of alkaline chemicals input when the mercury concentration is normal, the alkaline chemicals reduce the function of reducing hydrogen chloride in the combustion exhaust gas to some extent, while the alkaline chemicals are used for mercury such as activated carbon. It is possible to alleviate the inhibition of the mercury adsorption reaction by the adsorption agent. Therefore, according to the combustion exhaust gas treatment device of the present invention, the mercury concentration emitted from the chimney can be stably kept below the regulation value.

According to the combustion exhaust gas treatment device of the present invention, a dust collector for collecting and removing mercury-containing fly ash in the combustion exhaust gas is further provided, and the mercury removal chemical charging device burns a dry mercury removal chemical. Since it is injected into the exhaust gas, even if the mercury removing agent and the alkaline agent are collected together in this dust collector, the alkaline agent also has a function of reducing hydrogen chloride in the combustion exhaust gas to some extent. While reducing the amount, it is possible to alleviate that the alkaline agent inhibits the mercury adsorption reaction by the mercury adsorbing agent such as activated carbon. Therefore, according to the combustion exhaust gas treatment device of the present invention, the mercury concentration emitted from the chimney can be stably kept below the regulation value.

According to the combustion exhaust gas treatment device of the present invention, a cleaning device for cleaning and removing the mercury component in the combustion exhaust gas is further provided, and the mercury removing chemical charging device uses the wet mercury removing chemical as the cleaning device. By adding it to the cleaning water for the purpose and adding it to the combustion exhaust gas, even if the mercury removing agent and the alkaline agent are used together in this cleaning device, the alkaline agent will remove hydrogen chloride in the combustion exhaust gas. It is possible to alleviate that the alkaline agent inhibits the mercury adsorption reaction by a mercury adsorbing agent such as a chelating agent while reducing the reducing function to some extent. Therefore, according to the combustion exhaust gas treatment device of the present invention, the mercury concentration emitted from the chimney can be stably kept below the regulation value.

According to the combustion exhaust gas treatment device of the present invention, a mercury analyzer for detecting an increase in the mercury concentration in the combustion exhaust gas is provided at a position upstream of the dust collector or the cleaning device in the combustion exhaust gas discharge path. Therefore, the amount of mercury chemicals input can be appropriately set according to the increase in mercury concentration in the combustion exhaust gas, and the amount of alkaline chemicals input can be appropriately reduced. Therefore, according to the combustion exhaust gas treatment device of the present invention, the mercury concentration emitted from the chimney can be stably kept below the regulation value.

It is a figure which shows the structure of the combustion exhaust gas processing apparatus of embodiment of this invention. It is a figure which shows the example of the detection result of the mercury removal rate and the acid gas component concentration. It is a figure which shows the structure of the combustion exhaust gas processing apparatus of another embodiment of this invention. It is a figure which shows the structure of the combustion exhaust gas processing apparatus of still another Embodiment of this invention.

(First Embodiment)
FIG. 1 shows a treatment device for combustion exhaust gas from a waste incinerator 11 as an example of an incinerator. The waste incinerator 11 includes an incinerator 12, a first flue 13, a second flue 14, a third flue 15, and a gas outlet 16 provided at the downstream end of the third flue 15. Be prepared. The exhaust gas path 31 is a flue from the waste incinerator 11 to the chimney 32. A bug filter 33 as a dust collector is installed in the exhaust gas path 31. In the illustrated device, an inlet 34 for a mercury removing agent is provided on the upstream side of the bag filter 33 in the exhaust gas path 31. The mercury removing chemical tank 35 is a tank for storing the mercury removing chemical, and the stored mercury removing chemical is transferred to the combustion exhaust gas in the exhaust gas path 31 via the supply path 36 and the inlet 34. It is possible to throw (spray) toward. The feed path 36 is provided with a rotary valve 37 for adjusting the feed amount. The mercury removing chemical charging device 38 includes a mercury removing chemical tank 35, a rotary valve 37, and a supply path 36.

As the mercury removing agent, activated carbon which is a dry agent, iodine-attached activated carbon, and sulfur-attached activated carbon are preferably used.

The input port 34 in the exhaust gas path 31 is provided on the downstream side of the gas discharge port 16 of the waste incinerator 11 and on the upstream side of the bag filter 33. Further, the first exhaust gas sampling port 41 is provided on the downstream side of the gas discharge port 16 of the waste incinerator 11 and on the upstream side of the input port 34. The first mercury analyzer 42 communicates with the sampling port 41 and can detect the concentration of mercury in the sampled exhaust gas.

A second exhaust gas sampling port 43 is provided on the downstream side of the bag filter 33 in the exhaust gas path 31. The second mercury analyzer 44 communicates with the sampling port 43 and can detect the concentration of mercury in the sampled exhaust gas. The second mercury analyzer 44 may be installed on the wake side of the bag filter 33 in the exhaust gas path 31, and is preferably installed in the chimney 32.

As the first and second mercury analyzers 42 and 44, various types (atomic mercury meter, morphological mercury meter, total amount mercury meter) can be used. Among them, as the first mercury analyzer 42, the one described in International Publication No. 2016/136714 can be preferably used. The mercury analyzer described in this international publication detects the amount of zero-valent atomic mercury contained in the sampling gas, and the amount of divalent mercury constituting a mercury compound such as a soluble mercury salt contained in the sampling gas is It is not detected, and by detecting only the amount of zero-valent atomic mercury without detecting the amount of divalent mercury, it is possible to detect an increase in the amount of mercury more quickly than an accurate measurement of the amount of mercury. It is something like that.

The control device 45 can input detection signals from the first and second mercury analyzers 42 and 44, and can output a control signal to the rotary valve 37 in order to adjust the rotation speed of the rotary valve 37. be.

The illustrated combustion exhaust gas treatment device is further provided with a device 51 for charging an alkaline chemical into the exhaust gas. The charging device 51 is provided with a charging port 52 provided on the upstream side of the bug filter 33 in the exhaust gas path 31, a tank 53 for storing alkaline chemicals, and a feeding path 54 from the tank 53 to the charging port 52. It is provided with a rotary valve 55 provided in the supply path 54. The first acid gas component concentration detecting device 56 communicates with the first sampling gas port 57 provided in the portion of the exhaust gas path 31 on the upstream side of the input port 52. The second acid gas component concentration detecting device 58 communicates with the second sampling gas port 59 provided in the portion of the exhaust gas path 31 on the downstream side of the bag filter 33. As the first and second acid gas component concentration detecting devices 56 and 58, for example, those for detecting the concentration of hydrogen chloride, and in detail, known appropriate devices can be used. The detection signals from the detection devices 56 and 58 are sent to the control device 45, and the control signal from the control device 45 is used for adjusting the rotation speed of the rotary valve 55.

The operation of the combustion exhaust gas treatment device having the above configuration will be described. In the waste incinerator 11, the waste that is incinerated on a daily basis as described above contains almost no mercury (for example, 0 to 30 μg / m ³ N). Therefore, in normal times, it is sufficient to constantly add a small amount of a mercury removing agent (for example, 10 to 50 mg / m ^{3 N) to the combustion exhaust gas by reducing the rotation speed of the rotary valve 37 by the control device 45.}

However, when the waste containing mercury is put into the incinerator 11 and burned, the amount of mercury in the combustion exhaust gas rises sharply (for example, 30 to 1000 μg / m ³ N), which is an abnormal time. This is quickly detected by the first mercury analyzer 42, the rotation speed of the rotary valve 37 is increased, and the required amount of the mercury removing agent is charged into the exhaust gas (for example, 50 to 500 mg / m ³ N). .. Further, when the second mercury analyzer 44 detects a mercury amount equal to or higher than the specified value, the rotation speed of the rotary valve 37 is similarly increased to add a required amount of the mercury removing agent into the exhaust gas. That is, feedforward control is performed based on the detection result of the first mercury analyzer 42, and feedback control is performed based on the detection result of the second mercury analyzer 44. These controls can be controlled by only one of them, but by using both of them in combination, mercury in the exhaust gas can be more reliably removed by the chemical agent. When the drug is activated carbon, mercury is adsorbed on the activated carbon and removed. Specifically, these controls can be PID control or other appropriate control form.

Chemicals such as activated carbon that have adsorbed mercury are subject to filtering processing in the bag filter 33, and are recovered from the exhaust gas in the bag filter 33. The mercury-containing drug recovered by the bag filter 33 is appropriately discharged to the outside of the system. Specifically, in the bag filter 33, combustion fly ash, a chemical for removing mercury, a reaction product of the chemical and mercury, and the like are collected and deposited on the filter as a dust layer. Then, for example, the constituents of the dust layer are wiped off as dust collecting ash by backwashing using compressed air or the like at predetermined time intervals. As a general rule, the dust collected ash that has been wiped off is discharged to the outside of the system. Alternatively, since the dust-collected ash that has been wiped off contains an unused exhaust gas treatment agent, it may be carried upstream of the bug filter 33 as a dust collector and reused by air transportation, conveyor transportation, or the like. ..

On the other hand, the combustion exhaust gas from the waste incinerator 11 may contain, for example, the above-mentioned hydrogen chloride as an acid gas component. Therefore, the concentration is detected by the first and second acid gas component concentration detecting devices 56 and 58, and the rotation speed of the rotary valve 55 is adjusted by the control device 45, so that a large amount of alkaline chemical is introduced into the exhaust gas. Then, a neutralization reaction with the acid gas component is caused. The reaction product is collected by the bug filter 33.

As the alkaline agent, calcium hydroxide (slaked lime), sodium hydrogen carbonate (baking soda), dolomite hydroxide and the like can be preferably used. The control method for charging the alkaline chemical can be the same as the charging method when charging the activated carbon. That is, a small amount of alkaline chemical is constantly added, feedforward control is performed based on the detection result of the first acid gas component concentration detection device 56, and feedback control is performed based on the detection result of the second acid gas component concentration detection device 58. I do. These controls can be controlled by only one of them, but by using both of them in combination, the acid gas component in the exhaust gas can be more reliably removed by the chemical agent. Specifically, these controls can be PID control or other automatic control in an appropriate control mode.

For example, in order to reduce the amount of alkaline chemicals input when the mercury concentration detection value increases compared to normal times, for example, the detection target value of the second acid gas component concentration detection device 58 is set. It should be raised compared to normal times. In particular, in the case of automatic control, by raising the detection target value of the second acid gas component concentration detecting device 58 as compared with normal times, the amount of alkaline chemicals input can be automatically reduced as compared with normal times. ..

By the way, when looking at the mercury contained in the combustion exhaust gas from the waste incinerator 11, about 70 to 90% by mass of mercury is divalent mercury upstream of the bag filter 33, which is a dust collector, and the rest is 0-valent. It is said to exist in the form of mercury. Of these, divalent mercury reacts with hydrogen chloride contained in the combustion exhaust gas to generate mercury chloride that is easily collected by the bag filter.

However, when the combustion exhaust gas contains a large amount of alkaline chemicals, the alkaline chemicals reduce hydrogen chloride in the combustion exhaust gas, which hinders the production of mercury chloride that is easily collected by the bag filter.

In particular, when a large amount of alkaline chemicals are contained in the combustion exhaust gas and the dust layer deposited on the bag filter, the mercury adsorption reaction by the mercury removing chemicals is not actively performed. Specifically, part of the mercury adsorption reaction by the mercury removing agent is carried out in the dust layer deposited on the bag filter 33. Further, a part of the reaction between the alkaline chemical and the acid gas component is also carried out in the dust layer deposited on the bag filter 33. Therefore, when the dust layer deposited on the bag filter 33 contains a large amount of alkaline chemicals, the alkaline chemicals reduce hydrogen chloride in the dust layer, so that hydrogen chloride contained in the combustion exhaust gas reacts with divalent mercury. This hinders the production of mercury chloride, which is easily collected by the bag filter. Therefore, if the dust layer contains a large amount of alkaline chemicals, the mercury adsorption reaction by the mercury removing chemicals will not be actively performed.

As a countermeasure, when a large amount of mercury is detected and the amount of mercury-removing chemicals added is larger than in normal times, the treatment is performed with the amount of alkaline chemicals added specially reduced. When the amount of the alkaline drug added is specially reduced, the amount of the alkaline drug added is monitored while monitoring the detection results of the first acid gas component concentration detecting device 56 and the second acid gas component concentration detecting device 58. Confirm that there is no problem even if the amount is reduced (do not exceed the exhaust gas regulation value of the chimney).

The first acid gas component concentration detecting device 56 may be installed on the upstream side of the bag filter 33 as a dust collector in the exhaust gas path 31, for example, a temperature reducing tower and a bag filter 33 (not shown). It is preferable that it is installed between the two, and it is more preferable that it is located on the upstream side of the temperature reducing tower. The second acid gas component concentration detecting device 58 may be installed on the wake side of the bag filter 33 in the exhaust gas path 31, and is preferably installed in the chimney 32.

FIG. 2 shows a measurement example of the detection result of the concentration of the acid gas component (hydrogen chloride), the input amount of the alkaline chemical (slaked lime) corresponding to the detection result, and the mercury removal rate. The horizontal axis represents the time. The vertical axis represents the acid gas component concentration, the amount of alkaline chemicals input, and the mercury removal rate. In the morning from 6:00 to just before 12:00, when the concentration of the acid gas component rises, the amount of alkaline drug input is increased by PID control accordingly, and the resulting concentration is reduced again. ing. Such an increase in the concentration of the acid gas component and a corresponding increase in the amount of the alkaline drug input occur in the morning.

Shortly before 12:00, that is, around 11:00, the concentration of the acid gas component suddenly increased, resulting in an abnormal state, and a large amount of alkaline chemicals was added at the operator's discretion. As a result, the concentration of the acid gas component has dropped sharply. Then, immediately after 12:00, the concentration of the acid gas component started to rise again. At this time, a slightly larger amount of alkaline chemical was continuously added until just before 15:00, and as a result, the concentration of the acid gas component was at a very low level. However, the mercury removal rate is reduced by continuously adding a slightly larger amount of alkaline chemicals.

Therefore, shortly before 15:00, the amount of the alkaline drug input is reduced more than before while monitoring the concentration of the acid gas component. As a result, after 15:00, the mercury removal rate increased and returned to the original level.

After that, the input amount of the alkaline drug has returned to the same state as in the morning by PID control.

As described above, according to the combustion exhaust gas treatment device of the embodiment of the present invention shown in FIG. 1, when the mercury concentration in the combustion exhaust gas increases as compared with normal times, the mercury agent by the mercury removal agent input device When the input amount of the mercury is increased as compared with the normal case, the input amount of the alkaline drug is decreased as compared with other cases. Therefore, the alkaline drug inhibits the mercury adsorption reaction by the mercury adsorbing agent such as activated carbon. This can be alleviated and the required mercury removal rate can be maintained.

(Second Embodiment)
FIG. 3 shows a combustion exhaust gas treatment device according to another embodiment of the present invention. This treatment device is a wet type treatment device in which a chelating agent is added (added to the washing water), which is different from the dry type treatment device in which activated carbon is added as described above. In this processing device, unlike the bug filter 33 and the mercury removing agent charging device 38 in the above-mentioned processing device, the cleaning device 61 is provided in the exhaust gas path 31. The cleaning device 61 is provided with a mercury removing chelate tank 62 storing a mercury removing chelating agent and an alkaline drug tank 63 storing an alkaline drug (for example, a liquid alkaline drug such as caustic soda water). The mercury removing chelating agent in the mercury removing chelate tank 62 and the alkaline agent in the alkaline agent tank 63 are in the form of washing water containing the chelating agent and the alkaline agent, and the opening degree is adjusted by the control device 45. It is designed to be put into the cleaning device 61 via the above. The cleaning water of the cleaning device 61 is continuously replaced with an appropriate amount of new cleaning water to recover mercury contained in the cleaning water.

When the mercury removing chelating agent stored in the mercury removing chelate tank 62 is put into the cleaning device 61, it can take in mercury in the combustion exhaust gas to form a chelate complex. In the cleaning device 61, the alkaline chemical is charged from the alkaline chemical tank 63, and the acid gas in the combustion exhaust gas is removed. In the system shown in FIG. 3, as in the case of the processing apparatus shown in FIG. 1, when a large amount of mercury is detected, the amount of the mercury removing chelating agent input is larger than in normal times. In this case, it is possible to prevent a decrease in the mercury removal rate by performing the treatment in a state where the amount of the alkaline chemical added is particularly small.

(Third Embodiment)
FIG. 4 shows a combustion exhaust gas treatment apparatus according to still another embodiment of the present invention. In the device of FIG. 4, in addition to the device shown in FIG. 1, a waste incinerator 11 is provided with a superheater boiler tube 17 as a heat exchange device for heat exchange of combustion exhaust gas generated in the combustion furnace 12. The structure is provided with a soot blower 21 as a fly ash removing device for removing mercury-containing fly ash accumulated on the heater boiler tube 17. Reference numeral 24 denotes an on-off valve for the soot blower, and reference numeral 27 denotes a soot blower control device for controlling the operation of the on-off valve 24. The soot blower control device 27 can send and receive signals to and from the control device 45.

In the apparatus shown in FIG. 4, similarly to the apparatus of FIG. 1, the mercury concentration is determined by incinerating the mercury-containing waste in the garbage incinerator 11 when the removal work by the soot blower 21 described later is not performed. At the time of ascending, the treatment is carried out with the amount of the alkaline chemical added particularly small.

In addition, in the apparatus shown in FIG. 4, the superheater boiler pipe 17 of the third flue 15 of the waste incinerator 11 is generated when the waste is incinerated in the incinerator 12 of the waste incinerator 11. Fly ash accumulates. Then, in the superheater boiler pipe 17, the heat recovery efficiency is lowered due to the accumulation of fly ash, and the pipe may be corroded by the hydrogen chloride component contained in the accumulated fly ash. Therefore, it is necessary to periodically use the soot blower 21 to remove the accumulated fly ash. The wiping work by the soot blower 21 is carried out, for example, by blowing steam onto the superheater boiler pipe 17. By carrying out this work for about 30 minutes to 1 hour, the accumulated fly ash can be removed.

When the mercury-containing material is incinerated in the incinerator 12, mercury is contained in the accumulated fly ash of the superheater boiler pipe 17.

From the above, when the accumulated fly ash containing the hydrogen chloride component and mercury is removed, the removed fly ash is discharged from the gas discharge port 16 of the waste incinerator 11 to the exhaust gas path 31.

Then, the mercury concentration detected by the first mercury analyzer 42 and the second mercury analyzer 44 increases. At this time, by charging a large amount of mercury removing chemicals into the exhaust gas from the charging device 38 in the same manner as described above, the mercury scattered during the work of removing the accumulated fly ash can be recovered. At this time, as in the case of the above-described embodiment, it is possible to prevent a decrease in the mercury removal rate by performing the treatment in a state where the amount of the alkaline chemical added is specially reduced within a range where there is no problem.

According to the present invention, even when the mercury concentration of the combustion exhaust gas from the waste incinerator 11 increases due to some reason other than the above, the treatment is performed in a state where the amount of the alkaline chemical input is specially reduced. , It is possible to prevent a decrease in the mercury removal rate.

(others)
In any of the above-described embodiments, the activated carbon adsorption tower can be installed on the downstream side of the bag filter 33 along the exhaust gas path 31.

In the above, a waste incinerator has been exemplified as a source of combustion exhaust gas from which mercury should be removed. However, the present invention is not limited to this, and can be applied to combustion exhaust gas from other devices such as a coal combustion device.

In any of the above-described embodiments, an auxiliary agent for adjusting the thickness of the dust layer in the bag filter 33 can be added to the bag filter 33 or an arbitrary position on the upstream side of the exhaust gas path 31. The configuration can be adopted. As the auxiliary agent, "Bag Ace (registered trademark)" manufactured by Hitachi Zosen Corporation, activated carbon, or the like can be preferably used.

In each of the above-described embodiments, the rotary valve is exemplified as the charging device for the mercury removing drug, but any device that can control the charging amount of the drug is sufficient, and the drug cut out by the table feeder is blown. An air transport device or the like can be used.

The configurations described above can be appropriately combined within a range that does not contradict each other. For example, the recovery device may be a combustion exhaust gas treatment device including both a dry treatment device and a wet treatment device.

11 Waste incinerator 12 Combustion furnace 31 Exhaust gas path 33 Bug filter (dust collector)
38 Mercury removal chemical charging device 42 First mercury analyzer 44 Second mercury analyzer 45 Control device 51 Alkaline chemical charging device 61 Cleaning device 62 Mercury removal chelate tank 63 Alkaline tank

Claims (3)

Combustion furnace and
A mercury removing chemical charging device for charging mercury removing chemicals into the combustion exhaust gas generated in the combustion furnace, and a mercury removing chemical charging device.
An alkaline chemical charging device that charges alkaline chemicals into the combustion exhaust gas generated in the combustion furnace, and an alkaline chemical charging device.
A control device that controls the amount of mercury chemicals charged into the combustion exhaust gas by the mercury removing chemical charging device, and a control device that controls the amount of alkaline chemicals charged into the combustion exhaust gas by the alkaline chemical charging device.
A dust collector for collecting and removing mercury-containing fly ash in combustion exhaust gas or a cleaning device for cleaning and removing mercury components in combustion exhaust gas.
A mercury analyzer for detecting the mercury concentration in the combustion exhaust gas, which is provided at a position upstream of the dust collector or the cleaning device in the emission path of the combustion exhaust gas, and
With
When the mercury concentration in the flue gas detected by the mercury analyzer becomes abnormally high, the control device sets the amount of the alkaline drug charged by the alkaline drug charging device to the combustion. A combustion exhaust gas treatment device characterized in that the mercury concentration in the exhaust gas is reduced as compared with the amount of alkaline chemicals input when the concentration is normal. The combustion exhaust gas treatment device according to claim 1, wherein the mercury removing chemical charging device is for charging a dry mercury removing chemical into the combustion exhaust gas. The device according to claim 1 or 2, wherein the mercury removing chemical charging device is a device in which a wet mercury removing chemical is added to the cleaning water for the cleaning device and charged into the combustion exhaust gas. Combustion exhaust gas treatment equipment.

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