JP2017213499A - Exhaust gas treatment facility and exhaust gas treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust gas treatment facility and an exhaust gas treatment method capable of suppressing the used amount of activated carbon and improving filtration rate.SOLUTION: In an exhaust gas treatment facility 5A in which harmful substances in an exhaust gas are removed by disposing a bag filter device 12 with a filter cloth 31 in the middle of an exhaust gas flow passage flowing the exhaust gas containing dust and the harmful substances, supplying activated carbon to the upstream side of the bag filter device 12 in the exhaust gas flow passage, adsorbing the harmful substances in the exhaust gas by the supplied activated carbon and collecting the harmful substance-adsorbed activated carbon by the filter cloth 31, a preceding dust collector 11 for removing dust in the exhaust gas is disposed at an upstream side from the supply position of activated carbon in the exhaust gas in the exhaust gas flow passage, and dust contained in the exhaust gas before being introduced into the bag filter device 12 is preliminarily removed in the preceding dust collector 11.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to an exhaust gas treatment facility and an exhaust gas treatment method for treating exhaust gas generated, for example, in a waste incineration facility. The present invention relates to an exhaust gas treatment facility and an exhaust gas treatment method in which harmful substances such as carbon are adsorbed by activated carbon and the activated carbon is collected by a bag filter device to remove harmful substances in the exhaust gas.

  Conventionally, in a waste incineration treatment facility 101 as shown in FIG. 3, exhaust gas generated as the waste is combusted in the incinerator 102 is sent to the boiler 103 and the economizer 104 for heat recovery. Since the exhaust gas contains dust and harmful substances such as dioxins and mercury, the exhaust gas after heat recovery is sent to the exhaust gas treatment facility 105, and then the chimney 107 is moved by the induction fan 106. It is discharged to the outside through.

  The exhaust gas treatment facility 105 includes a bag filter device 108 disposed in the middle of the exhaust gas flow path between the economizer 104 and the induction fan 106. The bag filter device 108 includes a predetermined filter for separating and removing dust. A number of filter cloths 109 are provided. The dust (fly ash) or the like separated and removed from the exhaust gas by the bag filter device 108 is sent to the fly ash treatment device 110.

Activated carbon for adsorbing harmful substances is supplied to the upstream side of the bag filter device 108 by the activated carbon supply device 111, and exhaust gas containing dust and harmful substances is introduced into the bag filter device 108 together with the activated carbon. . In this exhaust gas treatment facility 105, harmful substances contained in the exhaust gas are adsorbed with activated carbon, and the activated carbon is collected together with dust by the filter cloth 109 disposed inside the bag filter device 108, thereby causing harmful substances in the exhaust gas. The material is to be removed. An apparatus in which activated carbon is blown into the upstream side of the bag filter device 108 to separate and remove harmful substances in the exhaust gas is widely used in practice (see, for example, Patent Documents 1 and 2).
Although detailed explanation by illustration is omitted, harmful substance removal equipment such as an active coke tower and activated carbon adsorption tower is separately provided on the rear side (downstream side) of the bag filter device, and in this exhaust gas in the exhaust gas by this harmful substance removal equipment. Some are designed to remove harmful substances.

JP 2001-137657 A Japanese Patent Laid-Open No. 2006-7572

However, in the conventional exhaust gas treatment facility 105, when the activated carbon having adsorbed harmful substances is collected by the filter cloth 109, a large amount of dust flying from the incinerator 102 is also collected at the same time. Since dust accumulates, there are the following problems.
(1) In order to remove a large amount of dust generated from the incinerator 102 from the filter cloth 109, the number of backwash operations increases, and the activated carbon is removed together with the dust by backwashing. .
(2) Since a large amount of dust comes from the incinerator 102 to the filter cloth 109 and the pressure loss in the bag filter device 108 increases, it is necessary to slow down the filtration rate. Therefore, the number of filter cloths incorporated in the bag filter device 108 increases, and the device becomes large.

  In addition, in the case of using an active coke tower or an activated carbon adsorption tower, chemicals such as active coke and activated carbon cannot be replaced during operation, and therefore, a large amount of chemical is filled in the tower in consideration of a margin. There is a problem in that the amount of medicine used increases because it is necessary to periodically replace all of the large amount of medicine filled in the tower.

  The present invention has been made in view of the problems as described above, and provides an exhaust gas treatment facility and an exhaust gas treatment method capable of suppressing the amount of activated carbon used and improving the filtration rate. It is the purpose.

In order to achieve the above object, an exhaust gas treatment facility according to the first invention comprises:
A bag filter device provided with a filter cloth is disposed in the middle of the exhaust gas flow path through which exhaust gas containing dust and harmful substances flows, and activated carbon is supplied to the upstream side of the bag filter device in the exhaust gas flow path. In the exhaust gas treatment equipment that adsorbs harmful substances in the exhaust gas with the activated carbon and removes the harmful substances in the exhaust gas by collecting the activated carbon adsorbing the harmful substances with the filter cloth,
A pre-stage dust collector for removing dust in the exhaust gas is disposed upstream of the activated carbon supply position in the exhaust gas flow path, and dust contained in the exhaust gas before being introduced into the bag filter device is disposed. It has been previously removed by the pre-stage dust collector.

Next, an exhaust gas treatment method according to the second invention is as follows.
An exhaust gas treatment method using the exhaust gas treatment facility according to the first invention,
When constantly supplying a predetermined amount of activated carbon to the upstream side of the bag filter device in the exhaust gas flow path, when the differential pressure between the upstream side and the downstream side of the bag filter device exceeds a specified value every predetermined time, The filter cloth is backwashed with a predetermined cycle time.

The exhaust gas treatment method according to the third invention is
An exhaust gas treatment method using the exhaust gas treatment facility according to the first invention,
In the case where a predetermined amount of activated carbon is intermittently supplied to the upstream side of the bag filter device in the exhaust gas flow path, the filter cloth is back-washed at a predetermined cycle time every predetermined time, and the activated carbon is only immediately after the back-washing. It is characterized by supplying.

  In the second or third invention, when the concentration of harmful substances contained in the exhaust gas on the downstream side of the bag filter device is increased, a larger amount of activated carbon is supplied than the predetermined amount of activated carbon, and the predetermined cycle time is increased. It is preferable to carry out backwashing with a shorter cycle time (fourth invention).

Next, an exhaust gas treatment method according to the fifth invention is:
An exhaust gas treatment method using the exhaust gas treatment facility according to the first invention,
The mercury removal amount by activated carbon is calculated by integrating the difference in the concentration of harmful substances contained in the exhaust gas between the upstream side and the downstream side of the bag filter device, and if the calculated mercury removal amount reaches a predetermined value, the filter cloth In contrast, backwashing is performed.

An exhaust gas treatment method according to the sixth invention is
An exhaust gas treatment method using the exhaust gas treatment facility according to the first invention,
The life of the activated carbon on the filter cloth is predicted based on the integrated value of the amount of exhaust gas passing through the filter cloth, and the filter cloth is backwashed when the predicted life is reached.

An exhaust gas treatment method according to the seventh invention
An exhaust gas treatment method using the exhaust gas treatment facility according to the first invention,
The supply amount of activated carbon is controlled by feedforward control based on the concentration of harmful substances contained in the exhaust gas upstream of the bag filter device.

An exhaust gas treatment method according to the eighth invention
An exhaust gas treatment method using the exhaust gas treatment facility according to the first invention,
The feed amount of activated carbon is controlled by feedforward control based on the concentration of harmful substances contained in the exhaust gas upstream of the bag filter device and feedback control based on the concentration of harmful substances contained in the exhaust gas downstream of the bag filter device. It is characterized by controlling.

An exhaust gas treatment method according to the ninth invention
An exhaust gas treatment method using the exhaust gas treatment facility according to the first invention,
When a predetermined amount of activated carbon is intermittently supplied to the upstream side of the bag filter device in the exhaust gas flow path, a predetermined amount of catalyst powder that decomposes harmful substances in the exhaust gas is simultaneously or non-simultaneously supplied with the activated carbon. It supplies to the upstream of the said bag filter apparatus in a flow path, It is characterized by the above-mentioned.

  According to the exhaust gas treatment facility of the first invention, the dust contained in the exhaust gas before being introduced into the bag filter device is removed in advance by the pre-stage dust collector, so that the exhaust gas after the dust is removed enters the bag filter device. It will be introduced and dust can be prevented from accumulating on the filter cloth. Since dust does not accumulate on the filter cloth, the number of backwashes is reduced, the amount of activated carbon that is washed away by backwashing is reduced, and the amount of activated carbon used can be reduced. Further, since dust does not accumulate on the filter cloth, pressure loss does not increase, and thus the filtration rate can be improved.

  According to the exhaust gas treatment method of the second invention, a predetermined amount of activated carbon is constantly supplied to the upstream side of the bag filter device in the exhaust gas flow path, and the differential pressure between the upstream side and the downstream side of the bag filter device is defined at regular intervals. When the value is exceeded, backwashing is performed on the filter cloth with a predetermined cycle time, so that harmful substances in the exhaust gas can be reliably removed.

  According to the exhaust gas treatment method of the third aspect of the invention, a predetermined amount of activated carbon is intermittently supplied to the upstream side of the bag filter device in the exhaust gas flow path, and the filter cloth is back-washed at a predetermined cycle time every predetermined time. Since activated carbon is supplied only immediately after the backwashing, harmful substances in the exhaust gas can be reliably removed while reducing the amount of activated carbon used.

  By adopting the configuration of the fourth aspect of the invention, even if the concentration of harmful substances in the exhaust gas increases, the harmful substances can be reliably removed.

  According to the fifth invention, the mercury removal amount by the activated carbon is calculated by integrating the difference in the concentration of harmful substances contained in the exhaust gas between the upstream side and the downstream side of the bag filter device, and the calculated mercury removal amount becomes a predetermined value. If it reaches, it is designed to backwash the filter cloth, so the timing of backwashing can be determined from the amount of mercury removed, and backwashing can be performed at a more appropriate timing. It can be reduced more.

  According to the sixth aspect of the invention, the life of the activated carbon on the filter cloth is predicted based on the integrated value of the amount of exhaust gas passing through the filter cloth, and when the predicted life is reached, the filter cloth is backwashed. Therefore, the timing of backwashing can be determined from the lifetime of the activated carbon on the filter cloth based on the integrated value of the amount of exhaust gas passing through the filter cloth, and backwashing can be performed at a more appropriate timing. The amount can be further reduced.

  By the way, when controlling the supply amount of activated carbon supplied to the upstream side of the bag filter device by feedback control based on the concentration of harmful substances contained in the exhaust gas after passing through the bag filter device, the supply timing of activated carbon is delayed, Removal of harmful substances may be delayed, and a large amount of activated carbon must be continuously blown. Therefore, if the supply amount of activated carbon is controlled by feedforward control based on the concentration of harmful substances contained in the exhaust gas upstream of the bag filter device (seventh invention), an appropriate amount of activated carbon is supplied at an appropriate timing. It is possible to remove harmful substances reliably.

  According to the eighth invention, feedforward control based on the concentration of harmful substances contained in the exhaust gas upstream of the bag filter device and feedback control based on the concentration of harmful substances contained in the exhaust gas downstream of the bag filter device. Since the supply amount of activated carbon is controlled by the above, the optimum amount of activated carbon can be supplied at a more appropriate timing, and harmful substances can be more reliably removed.

  According to the exhaust gas treatment method of the ninth aspect of the invention, a predetermined amount of catalyst powder for decomposing harmful substances in the exhaust gas is supplied to the upstream side of the bag filter device in the exhaust gas flow path simultaneously or non-simultaneously with the supply of the activated carbon. Therefore, a mixed layer of activated carbon and catalyst powder, or a composite layer in which a single layer of activated carbon and a single layer of catalyst powder are alternately laminated is formed, and harmful substances can be decomposed and removed more effectively.

1 is a schematic system configuration diagram of a waste incineration facility including an exhaust gas treatment facility according to a first embodiment of the present invention. It is a schematic system block diagram of a waste incineration facility provided with the waste gas processing equipment concerning the 2nd Embodiment of this invention. It is a schematic system block diagram of a waste incineration facility provided with the conventional waste gas treatment equipment.

  Next, specific embodiments of the exhaust gas treatment facility and the exhaust gas treatment method according to the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 shows a schematic system configuration diagram of a waste incineration facility equipped with an exhaust gas treatment facility according to the first embodiment of the present invention.

<Description of waste incineration facilities>
In the waste incineration facility 1 as shown in FIG. 1, the exhaust gas generated as the waste is combusted in the incinerator 2 is sent to the boiler 3 and the economizer 4 for heat recovery. The exhaust gas contains dust and heavy metals, and also contains acidic gas such as SOx, and harmful substances such as dioxins and NOx, so the exhaust gas after heat recovery was sent to the exhaust gas treatment facility 5A. Later, it is discharged to the outside through the chimney 7 by the attracting fan 6.

<Description of exhaust gas treatment equipment>
The exhaust gas treatment facility 5 </ b> A mainly includes a pre-stage dust collector 11, a bag filter device 12, a slaked lime supply device 13, and an activated carbon supply device 14.
Here, the pre-stage dust collector 11 and the bag filter device 12 are incorporated in the middle of the exhaust gas flow path through which the exhaust gas flows between the economizer 4 and the attracting fan 6, and the pre-stage dust collector 11 is located upstream of the bag filter device. 12 are respectively arranged on the downstream side.

The economizer 4 and the pre-stage dust collector 11 are connected by a duct 16 that forms an exhaust gas passage between them. Similarly, the upstream dust collector 11 and the bag filter device 12 are connected by a duct 17, and the bag filter device 12 and the induction fan 6 are connected by a duct 18.
The duct 17 is provided with an upstream mercury analyzer 21, and the duct 18 is provided with a downstream mercury analyzer 22. The upstream mercury analyzer 21 measures the concentration of mercury contained in the exhaust gas after passing through the pre-stage dust collector 11 and before the activated carbon is supplied by the activated carbon supply device 14, and the downstream mercury analyzer 22 The mercury concentration contained in the exhaust gas after passing through the bag filter device 12 is measured, and the measurement signals of the mercury analyzers 21 and 22 are sent to the control devices 44 and 55 described later. The duct 18 is further provided with an exhaust gas flow meter 23. The exhaust gas flow meter 23 measures the amount of exhaust gas that has passed through the bag filter device 12, and the measurement signal of the exhaust gas flow meter 23 is sent to a control device 55 described later. Sent.
The differential pressure (ΔP) between the pressure in the duct 17 on the upstream side (inlet side) of the bag filter device 12 and the pressure in the duct 18 on the downstream side (outlet side) of the bag filter device 12 is a differential pressure gauge 24. The measurement signal of the differential pressure gauge 24 is sent to a control device 55 described later.

  As the pre-stage dust collector 11, for example, a filtration dust collector, an electric dust collector, a centrifugal dust collector, or the like is preferably used. Here, the filtration dust collector is of a type in which exhaust gas containing dust is filtered through a cloth or non-woven bag-like filter that is installed, and the electrostatic precipitator removes dust in the exhaust gas by corona discharge. This is a system that collects dust using the electrostatic force of the high-voltage electric field that is charged. Centrifugal dust collectors give a swirling motion to the exhaust gas, and dust is extracted from the exhaust gas by the centrifugal force acting on the dust. It is a system of separating and collecting.

<Description of bug filter device>
The bag filter device 12 is the above-described filtration type dust collector, and a required filter cloth 31 is incorporated in the casing 30. Note that dust collected by the bag filter device 12, that is, fly ash, is sequentially discharged via a screw conveyor, a rotary valve, or the like (not shown) and conveyed to the fly ash treatment facility 20.

  The inside of the casing 30 is partitioned up and down by a cage plate 32. In the casing 30, an exhaust gas chamber 33 before filtration is disposed below the cage plate 32, and an exhaust gas chamber after filtration is disposed above the cage plate 32. 34 are respectively formed in sections. An exhaust gas inlet 35 connected to the duct 17 is formed in the exhaust gas chamber 33 before the filtration treatment, while an exhaust gas outlet port 36 connected to the duct 18 is formed in the exhaust gas chamber 34 after the filtration treatment. Yes. The cage plate 32 is provided with a required number of openings for suspending the filter cloth 31, and the suspension support is provided so that the filter cloth 31 is disposed in the exhaust gas chamber 33 before filtration from each opening. Has been.

  The filter cloth 31 is a cylindrical bag, and the closed one end side (lower end side) is inserted into the pre-filtration exhaust gas chamber 33, while the opened other end side (upper end side) is after the filtration process. It is arranged facing the exhaust gas chamber 34, and an aggregate (not shown) for maintaining the cylindrical shape is incorporated in the filter cloth 31. In addition, as a constituent material of the filter cloth 31, for example, a woven cloth such as a double weaving, a twill weaving, a plain weaving made of glass fiber or PTFE fiber, or felt is preferably used. Instead of the filter cloth 31, a catalyst-supporting filter cloth in which a catalyst that decomposes harmful substances is supported on the filter cloth, or a catalyst pre-coated filter cloth in which catalyst powder is attached to the filter cloth may be employed.

<Description of slaked lime supply device>
The slaked lime supply device 13 supplies slaked lime as an acidic gas removing agent for removing acidic gas such as SOx into the duct 16, and the slaked lime supplied into the duct 16 is exhaust gas flowing in the duct 16. The air is transported by the air and blown into the front dust collector 11.

<Description of activated carbon supply device>
The activated carbon supply device 14 includes an activated carbon tank 41 that stores activated carbon as a harmful substance adsorbent for adsorbing harmful substances such as dioxins and mercury, a feeder 42 that sends activated carbon stored in the activated carbon tank 41, and a feeder. In order to guide the activated carbon sent out from 42 to the duct 17, an activated carbon supply pipe 43 that connects the feeder 42 and the duct 17 and a control device 44 that controls the feeder 42 are provided. Based on the control signal, the feeder 42 sends out the activated carbon stored in the activated carbon tank 41, and the delivered activated carbon is supplied into the duct 17 through the activated carbon supply pipe 43. The activated carbon supplied into the duct 17 is pneumatically transported by the exhaust gas flowing through the duct 17 and blown into the bag filter device 12.

  The control device 44 performs arithmetic processing for performing control for supplying a predetermined amount of activated carbon constantly or intermittently, and transmits a predetermined control signal calculated as a result to the feeder 42. Sends the activated carbon to the duct 17 in accordance with the predetermined control signal. In addition, the control device 44 performs arithmetic processing for executing control that combines feedforward control based on the measurement value of the upstream mercury analyzer 21 and feedback control based on the measurement value of the downstream mercury analyzer 22. Then, a predetermined control signal calculated as a result is transmitted to the feeder 42, and the feeder 42 sends activated carbon to the duct 17 in accordance with the predetermined control signal.

<Description of withdrawal device>
The bag filter device 12 is provided with a pay-off device 50. The dropping device 50 includes an air compressor 51, a main supply pipe 52 through which the compressed air from the air compressor 51 is circulated, and a branch supply pipe branched from the main supply pipe 52 and connected to a group of filter cloths 31. 53 and a valve 54 for opening and closing the pipe of the branch supply pipe 53. When the valve 54 is opened in response to an open command signal from the control device 55, the compressed air from the air compressor 51 is supplied to the main supply pipe 52 and Activated carbon or the like deposited and deposited on the outer surface side of the filter cloth 31 by being injected to the inner surface side of the filter cloth 31 through the branch supply pipe 53 and passing compressed air from the inner peripheral side to the outer peripheral side of the filter cloth 31. It can be blown away.

  In the exhaust gas treatment facility 5A configured as described above, the exhaust gas after heat recovery by the boiler 3 or the economizer 4 is introduced into the interior of the pre-stage dust collector 11, and the duct 16 is supplied by the slaked lime supply device 13. The slaked lime supplied inside is blown into the inside of the pre-stage dust collector 11 by pneumatic transportation by the exhaust gas. Thereby, dust, acid gas, heavy metals, etc. contained in the exhaust gas after heat recovery are removed. The exhaust gas after dust, acid gas, heavy metals and the like are removed by the pre-stage dust collector 11 is introduced into the bag filter device 12 through the duct 17.

The control device 44 performs arithmetic processing for performing control for supplying a predetermined amount of activated carbon constantly or intermittently, and transmits a predetermined control signal calculated as a result to the feeder 42. Sends the activated carbon to the duct 17 in accordance with the predetermined control signal. As a result, a predetermined amount of activated carbon is constantly or intermittently supplied to the duct 17.
In addition, the control device 44 performs arithmetic processing for executing control that combines feedforward control based on the measurement value of the upstream mercury analyzer 21 and feedback control based on the measurement value of the downstream mercury analyzer 22. Then, a predetermined control signal calculated as a result is transmitted to the feeder 42, and the feeder 42 sends activated carbon to the duct 17 in accordance with the predetermined control signal. Thereby, the optimal amount of activated carbon is supplied at a more appropriate timing, and harmful substances can be more reliably removed.

  According to the exhaust gas treatment facility 5A of the present embodiment, since the exhaust gas after dust and the like are removed by the pre-stage dust collector 11 is introduced into the bag filter device 12, dust is prevented from accumulating on the filter cloth 31. be able to. Since dust does not accumulate on the filter cloth 31, the number of backwashing by the scraping device 50 is reduced, and the amount of activated carbon that is washed away by backwashing can be reduced, and the amount of activated carbon used can be suppressed. Moreover, since dust does not accumulate on the filter cloth 31, pressure loss does not increase, so that the filtration rate can be improved.

  By the way, in the case where a predetermined amount of activated carbon is constantly supplied to the duct 17, a bug occurs when the differential pressure measured by the differential pressure gauge 24 exceeds a specified value at regular intervals or by a timer of a built-in controller 55. The filter device 12 is subjected to low-speed backwashing with a low cycle time of 60 minutes, for example. That is, when one group is constituted by a plurality of filter cloths 31 and the number of groups is n, an opening command signal is sent from the control device 55 to each valve 54 corresponding to the n groups of the filter cloths 31. In a predetermined order every 60 / n minutes. Thus, by supplying compressed air to the n groups of filter cloths 31 every 60 / n in a predetermined order and backwashing every 60 minutes for a predetermined number of minutes, harmful substances in the exhaust gas are removed. It can be removed reliably.

  In the case where a predetermined amount of activated carbon is intermittently supplied to the duct 17, the bag filter device 12 is subjected to low-speed backwashing at the low cycle time at regular intervals, and the activated carbon supply device 14 only immediately after the backwashing. Supply activated carbon. Thereby, it is possible to reliably remove harmful substances in the exhaust gas while reducing the amount of activated carbon used.

  In any case where a predetermined amount of activated carbon is supplied to the duct 17 constantly or indirectly, a larger amount of activated carbon is supplied than the predetermined amount of activated carbon when the measured value of the downstream mercury analyzer 22 increases. As described above, the control device 44 controls the feeder 42, and the control device 55 sends an opening command signal to each of the valves 54 corresponding to the n groups of the filter cloth 31 at predetermined intervals every 60 / n minutes or less. High-speed backwashing is performed with a high cycle time shorter than the low cycle time by transmitting in order. Thereby, even if the density | concentration of the harmful substance in exhaust gas rises, a harmful substance can be removed reliably.

  Further, the control device 55 calculates the mercury removal amount by the activated carbon by integrating the difference between the measurement value of the upstream mercury analyzer 21 and the measurement value of the downstream mercury analyzer 22, and the calculated mercury removal amount is a predetermined value. If this value is reached, an open command signal is transmitted to the valve 54 so as to perform the low-speed backwashing at the low cycle time or the high-speed backwashing at the high cycle time as necessary. Thus, by determining the timing of backwashing from the mercury removal amount, backwashing can be performed at a more appropriate timing, and the amount of activated carbon used can be further reduced.

  Further, the control device 55 calculates an integrated value of the amount of exhaust gas passing through the filter cloth 31 based on the measurement signal from the exhaust gas flow meter 23, and the activated carbon on the filter cloth 31 is calculated based on the calculated integrated value of the exhaust gas amount. The service life is predicted, and when the predicted service life is reached, an open command signal is transmitted to the valve 54 to perform the low-speed backwash at the low cycle time or the high-speed backwash at the high cycle time as necessary. Like that. Thus, by determining the timing of backwashing from the lifetime of the activated carbon on the filter cloth 31 based on the integrated value of the amount of exhaust gas passing through the filter cloth 31, backwashing can be performed at a more appropriate timing. The amount can be further reduced.

[Second Embodiment]
FIG. 2 shows a schematic system configuration diagram of a waste incineration facility equipped with an exhaust gas treatment facility according to a second embodiment of the present invention. In the second embodiment, the same or similar parts as those of the first embodiment described above are designated by the same reference numerals in the drawings, and detailed description thereof is omitted. In the following, the second embodiment is described. The description will focus on the parts specific to the form.

  In the second embodiment, a catalyst powder supply device 60 that supplies catalyst powder that decomposes harmful substances into the duct 17 is provided, and the catalyst powder supplied into the duct 17 by the catalyst powder supply device 60 is the duct 17. The bag filter device 12 is blown into the bag filter 12 by air by the exhaust gas flowing inside.

  In the exhaust gas treatment facility 5B of the second embodiment, a predetermined amount of activated carbon is intermittently supplied to the duct 17 by the activated carbon supply device 14, and a predetermined amount of catalyst powder is supplied to the duct 17 by the catalyst powder supply device 60. It is supplied simultaneously or non-simultaneously with the supply of activated carbon. Accordingly, a mixed layer of activated carbon and catalyst powder, or a composite layer in which activated carbon single layers and catalyst powder single layers are alternately stacked is formed, and harmful substances can be decomposed and removed more effectively.

  The exhaust gas treatment facility and the exhaust gas treatment method of the present invention have been described based on a plurality of embodiments. However, the present invention is not limited to the configurations described in the above embodiments, and the configurations described in the respective embodiments. The configuration can be changed as appropriate without departing from the spirit of the invention, for example, by appropriately combining them.

  Since the exhaust gas treatment facility and the exhaust gas treatment method of the present invention have the characteristics that the amount of activated carbon used can be suppressed and the filtration rate can be improved, for example, waste incineration facilities and power plants, It can be suitably used for detoxification treatment of exhaust gas generated in various industrial furnaces, etc., and industrial applicability is great.

DESCRIPTION OF SYMBOLS 1 Waste incinerator 2 Incinerator 3 Boiler 4 Economizer 5A, 5B Exhaust gas treatment equipment 11 Pre-stage dust collector 12 Bag filter device 14 Activated carbon supply device 21 Upstream mercury analyzer 22 Downstream mercury analyzer 23 Exhaust gas flow meter 24 Differential pressure meter 50 Discharge device 60 Catalyst powder supply device

Claims (9)

A bag filter device provided with a filter cloth is disposed in the middle of the exhaust gas flow path through which exhaust gas containing dust and harmful substances flows, and activated carbon is supplied to the upstream side of the bag filter device in the exhaust gas flow path. In the exhaust gas treatment equipment that adsorbs harmful substances in the exhaust gas with the activated carbon and removes the harmful substances in the exhaust gas by collecting the activated carbon adsorbing the harmful substances with the filter cloth,
A pre-stage dust collector for removing dust in the exhaust gas is disposed upstream of the activated carbon supply position in the exhaust gas flow path, and dust contained in the exhaust gas before being introduced into the bag filter device is disposed. An exhaust gas treatment facility, which is previously removed by the upstream dust collector. An exhaust gas treatment method using the exhaust gas treatment facility according to claim 1,
When constantly supplying a predetermined amount of activated carbon to the upstream side of the bag filter device in the exhaust gas flow path, when the differential pressure between the upstream side and the downstream side of the bag filter device exceeds a specified value every predetermined time, An exhaust gas treatment method, wherein the filter cloth is back-washed with a predetermined cycle time. An exhaust gas treatment method using the exhaust gas treatment facility according to claim 1,
In the case where a predetermined amount of activated carbon is intermittently supplied to the upstream side of the bag filter device in the exhaust gas flow path, the filter cloth is back-washed at a predetermined cycle time every predetermined time, and the activated carbon is only immediately after the back-washing. An exhaust gas treatment method comprising:   When the concentration of harmful substances contained in the exhaust gas on the downstream side of the bag filter device increases, a larger amount of activated carbon is supplied than the predetermined amount of activated carbon, and backwashing is performed with a cycle time shorter than the predetermined cycle time. The exhaust gas treatment method according to claim 2, wherein the exhaust gas treatment method is performed. An exhaust gas treatment method using the exhaust gas treatment facility according to claim 1,
The mercury removal amount by activated carbon is calculated by integrating the difference in the concentration of harmful substances contained in the exhaust gas between the upstream side and the downstream side of the bag filter device, and if the calculated mercury removal amount reaches a predetermined value, the filter cloth An exhaust gas treatment method characterized by performing backwashing. An exhaust gas treatment method using the exhaust gas treatment facility according to claim 1,
An exhaust gas treatment method characterized by predicting the life of activated carbon on the filter cloth based on the integrated value of the amount of exhaust gas passing through the filter cloth, and backwashing the filter cloth when the predicted life is reached. An exhaust gas treatment method using the exhaust gas treatment facility according to claim 1,
An exhaust gas treatment method, wherein the supply amount of activated carbon is controlled by feedforward control based on a concentration of harmful substances contained in exhaust gas upstream of the bag filter device. An exhaust gas treatment method using the exhaust gas treatment facility according to claim 1,
The feed amount of activated carbon is controlled by feedforward control based on the concentration of harmful substances contained in the exhaust gas upstream of the bag filter device and feedback control based on the concentration of harmful substances contained in the exhaust gas downstream of the bag filter device. An exhaust gas treatment method characterized by controlling. An exhaust gas treatment method using the exhaust gas treatment facility according to claim 1,
When a predetermined amount of activated carbon is intermittently supplied to the upstream side of the bag filter device in the exhaust gas flow path, a predetermined amount of catalyst powder that decomposes harmful substances in the exhaust gas is simultaneously or non-simultaneously supplied with the activated carbon. An exhaust gas treatment method comprising supplying the bag filter device upstream of the bag filter device.

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