JPWO2018101030A1 - Exhaust gas treatment apparatus, incineration equipment, and exhaust gas treatment method - Google Patents

Abstract

The exhaust gas treatment apparatus includes a dust collector provided in the flue, a temperature reducing tower that is provided between the combustion chamber and the dust collector in the flue, and sprays water into the exhaust gas, and a combustion chamber and a temperature reducing tower in the flue. A first chemical supply unit that supplies an exhaust gas treatment chemical containing a calcium-based chemical to a position in between, and an exhaust gas treatment chemical containing a calcium chemical can be supplied to an auxiliary supply position between the combustion chamber and the dust collector in the flue A second chemical supply unit, an HCl concentration measurement unit that measures the HCl concentration in the exhaust gas, and the first chemical supply unit or the first chemical supply unit or the first chemical supply unit or the A control unit that increases the supply amount of the exhaust gas treatment chemicals by the two chemical supply units. As a result, the desalting process can be performed efficiently, and it is possible to appropriately cope with an abnormality in which the HCl concentration exceeds a predetermined value.

Description

  The present invention relates to technology for treating exhaust gas and incineration equipment.

  Conventionally, municipal wastes and other general wastes are incinerated by waste incineration equipment. The exhaust gas generated by the incineration process contains harmful substances such as dust, hydrogen chloride (HCl), sulfur oxide (SOx), nitrogen oxide (NOx), heavy metals (Pb, Hg, etc.). Therefore, a treatment for removing these harmful substances from the exhaust gas is performed by the exhaust gas treatment device, and the treated exhaust gas is discharged to the atmosphere. For example, in Japanese Patent Application Laid-Open No. 10-24213 (Reference 1), powdered slaked lime is introduced into a temperature reducing tower, moisture is absorbed into the slaked lime and reacted with the acid gas in the exhaust gas, thereby reducing the desalination rate. Techniques for improving are disclosed.

  By the way, when high chlorine content waste is incinerated, the HCl concentration of exhaust gas may temporarily become excessively high. In such a case, the apparatus of Literature 1 may not be able to suppress the increase in HCl concentration in a short time. Therefore, there is a demand for a technique that can efficiently perform desalting and appropriately cope with an abnormality when the HCl concentration exceeds a predetermined value.

  The present invention is directed to an exhaust gas treatment apparatus, and an object of the present invention is to efficiently perform a desalting treatment and appropriately cope with an abnormal time when the HCl concentration becomes a predetermined value or more.

  An exhaust gas treatment apparatus according to the present invention includes a dust collector provided in a flue through which exhaust gas flows, and a temperature reducing tower that is provided between the generation source of the exhaust gas and the dust collector in the flue and sprays water into the exhaust gas. And a position between the generation source in the flue and the temperature reducing tower, or a position in the temperature reducing tower as a chemical supply position, and an exhaust gas treatment chemical containing a calcium-based chemical at the chemical supply position. A first chemical supply unit to supply; a second chemical supply unit capable of supplying an exhaust gas treatment chemical containing a calcium-based chemical to an auxiliary supply position between the generation source and the dust collector in the flue; and the exhaust gas An HCl concentration measuring unit for measuring the concentration of HCl in the second chemical supply unit to the auxiliary supply position when the HCl concentration is less than the predetermined value when the HCl concentration exceeds a predetermined value. When the supply amount of the exhaust gas treatment chemical is increased, or when the HCl concentration is equal to or higher than a predetermined value, the HCl concentration is increased while the exhaust gas treatment chemical is supplied to the auxiliary supply position by the second chemical supply unit. A control unit that increases the supply amount of the exhaust gas treatment chemical to the chemical supply position by the first chemical supply unit more than when it is less than the predetermined value.

  ADVANTAGE OF THE INVENTION According to this invention, while performing a desalination process efficiently, it can respond appropriately using the 1st chemical | medical agent supply part or the 2nd chemical | medical agent supply part at the time of the abnormality where HCl concentration becomes more than predetermined value.

  In one preferred embodiment of the present invention, the first drug supply unit and the second drug supply unit share a storage unit that stores a calcium-based drug.

  In another preferred embodiment of the present invention, the second chemical supply unit supplies the dust collection ash collected by the dust collector as the exhaust gas treatment chemical.

  The present invention is also directed to an incineration facility. An incineration facility according to the present invention includes a combustion chamber for burning waste, a flue for discharging exhaust gas generated in the combustion chamber from the combustion chamber, and the exhaust gas treatment device provided in the flue. .

  The present invention is also directed to an exhaust gas treatment method in an exhaust gas treatment apparatus. In the exhaust gas treatment method according to the present invention, the exhaust gas treatment device is provided between a dust collector provided in a flue through which the exhaust gas flows, and the exhaust gas generation source and the dust collector in the flue, and water is contained in the exhaust gas. A temperature-decreasing tower that sprays the water, a position between the generation source in the flue and the temperature-decreasing tower, or a position in the temperature-decreasing tower as a medicine supply position, A second chemical agent capable of supplying an exhaust gas treatment chemical containing a calcium-based chemical to a first chemical supply unit for supplying an exhaust gas treatment chemical containing a gas to an auxiliary supply position between the generation source and the dust collector in the flue The exhaust gas treatment method includes: a) a position between the generation source and the temperature-decreasing tower in the flue, or in the temperature-decreasing tower, the exhaust gas by the first chemical supply unit. Supply processing chemicals B) measuring the HCl concentration in the exhaust gas; and c) supplying the second chemical more than when the HCl concentration is less than the predetermined value when the HCl concentration is greater than or equal to the predetermined value. When the supply amount of the exhaust gas treatment chemical to the auxiliary supply position by the unit is increased, or when the HCl concentration is equal to or higher than a predetermined value, the second chemical supply unit supplies the exhaust gas treatment chemical to the auxiliary supply position. And a step of increasing the supply amount of the exhaust gas treatment chemical to the chemical supply position by the first chemical supply unit as compared to when the HCl concentration is less than the predetermined value.

  The above object and other objects, features, aspects and advantages will become apparent from the following detailed description of the present invention with reference to the accompanying drawings.

It is a figure showing composition of incineration equipment concerning a 1st embodiment. It is a figure which shows the structure of an exhaust gas processing apparatus. It is a figure which shows the flow of waste gas treatment. It is a figure which shows the relationship between the desalination rate and equivalent ratio in the exhaust gas processing apparatus of a comparative example. It is a figure which shows the waste gas processing apparatus which concerns on 2nd Embodiment. It is a figure which shows the waste gas processing apparatus which concerns on 3rd Embodiment. It is a figure which shows the waste gas processing apparatus which concerns on 4th Embodiment. It is a figure which shows the waste gas processing apparatus which concerns on 5th Embodiment.

(First embodiment)
FIG. 1 is a diagram showing a configuration of an incineration facility 1 according to the first embodiment of the present invention. The incineration facility 1 is a facility for incinerating waste such as municipal waste. The incineration facility 1 includes a combustion chamber 2, a flue 3, an exhaust gas treatment device 4, an induction fan 51, and a chimney 52. In the combustion chamber 2, combustion of garbage and combustion of combustible gas generated from the garbage are performed. The flue 3 connects the combustion chamber 2 and the chimney 52. The exhaust gas treatment device 4 and the induction fan 51 are provided in the flue 3. The induction fan 51 discharges exhaust gas (combustion gas) generated in the combustion chamber 2 to the flue 3 and guides it to the chimney 52 through the exhaust gas treatment device 4. That is, the exhaust gas generated from the combustion chamber 2 flows through the flue 3 from the combustion chamber 2 toward the chimney 52, and the exhaust gas treatment device 4 performs a predetermined process on the exhaust gas. The chimney 52 releases exhaust gas to the atmosphere. In FIG. 1, the flue 3 is indicated by a thick solid line.

  FIG. 2 is a diagram showing the configuration of the exhaust gas treatment device 4. The exhaust gas treatment device 4 includes a temperature reducing tower 41, a chemical supply unit 42, a dust collector 43, an HCl concentration measurement unit 401, and a control unit 40. In the flue 3, a temperature reducing tower 41 and a dust collector 43 are sequentially provided from the combustion chamber 2 toward the chimney 52, that is, from the upstream side to the downstream side in the flow direction of the exhaust gas. A denitration device or the like may be provided between the dust collector 43 and the chimney 52.

  The temperature reducing tower 41 sprays water into the exhaust gas flowing from the combustion chamber 2 to lower the temperature of the exhaust gas. The temperature of the exhaust gas discharged from the temperature reducing tower 41 is about 170 ° C., for example. The drug supply unit 42 includes a slaked lime storage unit 421, a special auxiliary agent storage unit 422, a first drug pumping unit 423a, a second drug pumping unit 423b, a first drug supply line 424a, and a second drug supply line 424b. And fixed quantity supply parts 425 and 426.

  One end of the first drug supply line 424a is connected to the first drug pumping part 423a, and the other end is a position P1 between the combustion chamber 2 and the temperature reducing tower 41 in the flue 3 (hereinafter referred to as “drug supply position P1”). "). The 1st chemical | medical agent pumping part 423a is an air blower, and sends air toward the flue 3 in the 1st chemical | medical agent supply line 424a. One end of the second chemical supply line 424b is connected to the second chemical pumping unit 423b, and the other end is a position P2 between the temperature reducing tower 41 and the dust collector 43 in the flue 3 (hereinafter referred to as “auxiliary supply position P2”). Connected). The second medicine pumping unit 423b is a blower and sends air toward the flue 3 in the second medicine supply line 424b.

The slaked lime storage unit 421 stores powdered slaked lime (calcium hydroxide (Ca (OH) ₂ )) as a calcium (Ca) -based drug. Slaked lime is a desalting and desulfurizing agent. A fixed amount supply unit 425 is attached to the lower part of the slaked lime storage unit 421. The fixed amount supply unit 425 is, for example, a table feeder having two discharge ports, and the two discharge ports are connected to the first drug supply line 424a and the second drug supply line 424b, respectively. At each discharge port of the fixed amount supply unit 425, a set amount of slaked lime is taken out (cut out) from the slaked lime storage unit 421 per unit time. Thereby, slaked lime is supplied into the 1st chemical | medical agent supply line 424a and the 2nd chemical | medical agent supply line 424b.

The special auxiliary agent storage unit 422 stores a powdery drug (for example, Bag Ace (registered trademark) or activated carbon manufactured by Hitachi Zosen Corporation, hereinafter referred to as “special auxiliary agent”). A fixed amount supply unit 426 is attached to the lower part of the special auxiliary agent storage unit 422. The fixed amount supply unit 426 has two discharge ports like the fixed amount supply unit 425, and the two discharge ports are connected to the first drug supply line 424a and the second drug supply line 424b, respectively. At each discharge port of the quantitative supply unit 426, a set amount of special auxiliary agent is taken out from the special auxiliary agent storage unit 422 per unit time and supplied into the first drug supply line 424a and the second drug supply line 424b. With the chemical supply unit 42 configured as described above, it is possible to supply (blow) exhaust gas treatment chemicals including slaked lime and special auxiliary agents into the flue 3 at the chemical supply position P1 and the auxiliary supply position P2. The exhaust gas treatment chemical may include other calcium-based chemicals (calcium-containing chemicals) such as dolomite hydroxide [Ca (OH) ₂ .Mg (OH) ₂ ] instead of or together with slaked lime (others) The same applies to the embodiment).

  When the configuration for supplying the exhaust gas treatment chemical to the chemical supply position P1 is called a “first chemical supply unit 42a”, the first chemical supply unit 42a includes the slaked lime storage unit 421, the special auxiliary agent storage unit 422, and the first chemical agent. It includes a pumping unit 423a, a first medicine supply line 424a, and a fixed amount supply unit 425,426. Similarly, when the configuration for supplying the exhaust gas treatment chemical to the auxiliary supply position P2 is referred to as a “second chemical supply unit 42b”, the second chemical supply unit 42b includes a slaked lime storage unit 421, a special auxiliary agent storage unit 422, It includes a second drug pumping unit 423b, a second drug supply line 424b, and a quantitative supply unit 425,426. In the 1st chemical | medical agent supply part 42a and the 2nd chemical | medical agent supply part 42b, the slaked lime storage part 421 which stores slaked lime is shared, and the special adjuvant storage part 422 which stores a special adjuvant is also shared.

  The dust collector 43 is, for example, a filtration type, and removes fly ash contained in the exhaust gas with a filter cloth. The dust collector 43 is also called a bag filter. The exhaust gas treatment chemical supplied by the chemical supply unit 42 is deposited on the filter cloth. When the exhaust gas passes through the filter cloth inside the dust collector 43, a reaction between the harmful substance contained in the exhaust gas and the exhaust gas treatment chemical occurs, and the harmful substance is removed from the exhaust gas. The reaction between the exhaust gas and the exhaust gas treatment chemical also occurs in the flue 3 upstream of the dust collector 43. In the chemical supply unit 42, other types of exhaust gas treatment chemicals such as activated carbon may be supplied in addition to slaked lime. Examples of harmful substances removed by the exhaust gas treatment chemical include hydrogen chloride, sulfur oxides, dioxins, and mercury compounds.

  In the dust collector 43, fly ash and exhaust gas treatment chemicals (including reactants with harmful substances) deposited on the filter cloth are wiped out by backwashing using compressed air every predetermined time. Fly ash and exhaust gas treatment chemicals that have been wiped off from the filter cloth are conveyed to a dust collection ash treatment unit (not shown) and treated with, for example, a chelating agent (heavy metal stabilizer). Actually, part of the fly ash and the exhaust gas treatment chemical is also collected in the temperature reducing tower 41 provided between the combustion chamber 2 and the dust collector 43 in the flue 3 and transported to the fly ash treatment unit.

  The HCl concentration measuring unit 401 is provided in the flue 3 between the combustion chamber 2 and the temperature reducing tower 41 (for example, in the vicinity of the inlet of the temperature reducing tower 41), and uses a laser beam or the like to measure hydrogen chloride in the exhaust gas. The concentration (hereinafter referred to as “HCl concentration”) is measured. The HCl concentration acquired by the HCl concentration measuring unit 401 is output to the control unit 40. The controller 40 controls the drug supply unit 42 based on the HCl concentration. The control unit 40 is also responsible for overall control of the exhaust gas treatment device 4.

  FIG. 3 is a diagram showing the flow of exhaust gas treatment in the exhaust gas treatment device 4. In the exhaust gas treatment in the exhaust gas treatment device 4, the HCl concentration measurement unit 401 measures the HCl concentration in the exhaust gas (step S11). Further, the exhaust gas treatment chemical containing slaked lime and special auxiliary agent is supplied to the chemical supply position P1 by the first chemical supply unit 42a (step S12). At this time, the supply amount (supply amount per unit time) of the exhaust gas treatment chemical to the chemical supply position P1 can be controlled by adjusting the outputs of the first chemical pumping unit 423a and the quantitative supply units 425 and 426. It is. In the control unit 40, when the HCl concentration acquired by the HCl concentration measuring unit 401 is higher than a predetermined set value, the supply amount of the exhaust gas treatment chemical to the chemical supply position P1 is increased, and the HCl concentration is set to the predetermined set value. If lower than that, the supply amount of the exhaust gas treatment chemical to the chemical supply position P1 is preferably reduced.

In the slaked lime supplied to the chemical supply position P1, a reaction product (CaCl ₂ ) of slaked lime and hydrogen chloride is formed on the surface. Since slaked lime flows into the temperature reducing tower 41 together with the exhaust gas, the moisture concentration on the surface of the slaked lime increases. Furthermore, the reactant on the surface having a high solubility in water is dissolved in the water sprayed into the temperature reducing tower 41, that is, is removed from the surface of the slaked lime, and unreacted slaked lime appears on the surface. Thereby, the fall of the reaction rate by the reaction material in the slaked lime surface is suppressed. Therefore, in the exhaust gas treatment device 4 that supplies slaked lime to the chemical supply position P1 between the combustion chamber 2 and the temperature reducing tower 41 in the flue 3, the efficiency of the desalting reaction is improved (the HCl concentration is reduced with less slaked lime). ) Is possible. Similarly, when the exhaust gas treatment chemical contains another calcium chemical such as dolomite hydroxide, the reaction product with hydrogen chloride formed on the surface of the other calcium chemical is sprayed into the temperature reducing tower 41. And the decrease in reaction rate in the other calcium-based drug is suppressed.

  In parallel with step S12, the second chemical supply unit 42b supplies the exhaust gas treatment chemical containing slaked lime and special auxiliary agent to the auxiliary supply position P2 (step S13). At this time, the supply amount of the exhaust gas treatment chemical to the auxiliary supply position P2 can be controlled by adjusting the outputs of the second chemical pumping unit 423b and the quantitative supply units 425 and 426. In the control unit 40, the supply amount of the exhaust gas treatment chemical to the auxiliary supply position P2 is increased or decreased based on the HCl concentration. That is, when the HCl concentration is equal to or higher than the predetermined value, the supply amount of the exhaust gas treatment chemical to the auxiliary supply position P2 by the second chemical supply unit 42b is increased more than when the HCl concentration is less than the predetermined value. In particular, when high chlorine content waste is incinerated, the chlorine concentration in the exhaust gas rapidly rises, and when the control by the first chemical supply unit 42a cannot be dealt with, the control unit 40 causes the second chemical supply unit 42b to The supply amount of the exhaust gas treatment chemical to the auxiliary supply position P2 is increased. In step S13, when the HCl concentration is less than a predetermined value, the supply amount of the exhaust gas treatment chemical to the auxiliary supply position P2 by the second chemical supply unit 42b is 0 and the HCl concentration is equal to or higher than the predetermined value. The supply of the exhaust gas treatment chemical to the auxiliary supply position P2 may be started when an abnormality occurs.

  In the exhaust gas treatment device 4 of FIG. 2, measurement of HCl concentration (step S11), supply of exhaust gas treatment chemical by the first chemical supply unit 42a (step S12), and supply of exhaust gas treatment chemical by the second chemical supply unit 42b (step S12). Step S13) is in principle performed continuously in parallel with each other. The supply of the exhaust gas treatment chemical to the chemical supply position P1 or the auxiliary supply position P2 may be temporarily stopped.

  Here, the exhaust gas treatment device of the first comparative example that supplies the exhaust gas treatment chemical only to the chemical supply position P 1 between the combustion chamber 2 and the temperature reduction tower 41 in the flue 3, the temperature reduction tower 41 and the dust collector 43, Assume an exhaust gas treatment apparatus of a second comparative example that supplies an exhaust gas treatment chemical only to the auxiliary supply position P2 between the two. FIG. 4 is a diagram showing the relationship between the desalination rate and the equivalence ratio in the exhaust gas treatment apparatuses of the first and second comparative examples. Here, the exhaust gas treatment chemicals are adjusted so that the HCl concentration in the chimney 52 becomes a predetermined value. The supply amount was controlled. In FIG. 4, the broken line L21 shows the relationship between the desalination rate and the equivalence ratio in the exhaust gas treatment device of the first comparative example, and the solid line L22 shows the relationship between the desalination rate and the equivalence ratio in the exhaust gas treatment device of the second comparative example. Show. The equivalence ratio is a value of a ratio between the amount of slaked lime actually supplied and the amount of slaked lime theoretically necessary to completely remove hydrogen chloride and sulfur oxide in the exhaust gas. It is an index indicating the degree of excess. The desalination rate is the ratio of the amount of hydrogen chloride removed by the exhaust gas treatment device to the amount of hydrogen chloride before treatment. For example, the desalting rate is obtained by (1- (amount of hydrogen chloride after desalting) / (amount of hydrogen chloride before desalting)).

  In the exhaust gas treatment apparatus of the second comparative example, a reaction product of slaked lime and hydrogen chloride is formed on the surface of the powdered slaked lime, so that a new reaction with hydrogen chloride hardly occurs. Therefore, in order to obtain a predetermined desalination rate, it is necessary to increase the amount of slaked lime supplied into the flue 3. On the other hand, in the exhaust gas treatment apparatus of the first comparative example, the moisture concentration on the surface of the slaked lime becomes high, and further, the reactant on the surface of the slaked lime is removed by the water sprayed in the temperature reducing tower 41. When compared with the same equivalent ratio, a higher desalting rate is obtained as compared with the exhaust gas treatment apparatus of the second comparative example. In this way, by supplying the exhaust gas treatment chemical to the chemical supply position P1 between the combustion chamber 2 and the temperature reducing tower 41, it is possible to efficiently perform the desalting treatment.

  In the exhaust gas treatment device 4 of FIG. 2, the exhaust gas treatment chemical containing slaked lime is supplied to the chemical supply position P1 between the combustion chamber 2 and the temperature reducing tower 41 by the first chemical supply unit 42a. Thereby, in normal time, desalination performance can be improved by using slaked lime efficiently. As a result, in the incineration facility 1 having the exhaust gas treatment device 4, the running cost can be reduced by the efficient use of slaked lime (reduction in the amount of slaked lime used). The same applies when the exhaust gas treatment chemical contains other calcium-based chemicals.

  By the way, municipal waste is uneven. For example, when high chlorine content waste (high chlorine content waste) is introduced into the combustion chamber 2, the HCl concentration in the exhaust gas rapidly increases. Even in such a case, in the exhaust gas treatment device 4 having the second drug supply unit 42b in addition to the first drug supply unit 42a, the first drug supply unit is based on the HCl concentration acquired by the HCl concentration measurement unit 401. Both the 42a and the second chemical supply unit 42b are controlled, and the supply amount of the exhaust gas treatment chemical to both the chemical supply position P1 and the auxiliary supply position P2 is increased. In other words, in the exhaust gas treatment device 4, the supply amount of the exhaust gas treatment chemicals by the second chemical supply unit 42 b as well as the first chemical supply unit 42 a is increased at the time when the HCl concentration becomes a predetermined value or more. Accordingly, it is possible to appropriately cope with an abnormality, that is, it is possible to suppress a rapid increase in HCl concentration in a short time, and to stabilize the HCl concentration in the exhaust gas discharged from the chimney 52.

  In addition, by controlling the first chemical supply unit 42a and the second chemical supply unit 42b based on the HCl concentration, the exhaust gas treatment chemical can be used efficiently, and the running cost of the exhaust gas treatment device 4 can be reduced. In the exhaust gas treatment device 4, the first chemical supply unit 42a and the second chemical supply unit 42b share the slaked lime storage unit 421 that stores slaked lime, thereby simplifying the structure of the exhaust gas treatment device 4 (special The same applies to the auxiliary agent storage unit 422.)

(Second Embodiment)
FIG. 5 is a view showing an exhaust gas treatment device 4 according to the second embodiment of the present invention. In the exhaust gas treatment device 4 of FIG. 5, in the first chemical supply unit 42a and the second chemical supply unit 42b, slaked lime storage units 421a and 421b for storing slaked lime are individually provided, and special auxiliary agent storage for storing special auxiliary agents. The parts 422a and 422b are also provided individually. Further, the chemical supply position P1 is set in the temperature reduction tower 41, and the exhaust gas treatment chemical is supplied into the temperature reduction tower 41 by the first chemical supply unit 42a. Other configurations are the same as those in FIG. 2, and the same reference numerals are given to the same configurations.

  In the exhaust gas treatment device 4, the first chemical supply unit 42a includes a slaked lime storage unit 421a, a special auxiliary agent storage unit 422a, a first chemical pumping unit 423a, a first chemical supply line 424a, and quantitative supply units 425a and 426a. Including. One end of the first medicine supply line 424a is connected to the first medicine pumping unit 423a, and the other end is connected to the medicine supply position P1. The slaked lime in the slaked lime storage unit 421a is supplied into the first drug supply line 424a through the fixed amount supply unit 425a, and the special auxiliary agent in the special auxiliary agent storage unit 422a is the first drug through the fixed amount supply unit 426a. It is supplied into the supply line 424a. As a result, the exhaust gas treatment chemical containing slaked lime and special auxiliary agent is supplied to the chemical supply position P <b> 1 in the temperature reducing tower 41.

  The second drug supply unit 42b includes a slaked lime storage unit 421b, a special auxiliary agent storage unit 422b, a second drug pumping unit 423b, a second drug supply line 424b, and quantitative supply units 425b and 426b. One end of the second drug supply line 424b is connected to the second drug pumping unit 423b, and the other end is connected to the auxiliary supply position P2. The slaked lime in the slaked lime storage unit 421b is supplied into the second drug supply line 424b via the fixed amount supply unit 425b, and the special auxiliary agent in the special auxiliary agent storage unit 422b is supplied to the second drug through the fixed amount supply unit 426b. It is supplied into the supply line 424b. As a result, the exhaust gas treatment chemical containing slaked lime and special auxiliary agent is supplied to the auxiliary supply position P <b> 2 in the flue 3.

  In the exhaust gas treatment device 4 in which the slaked lime reservoirs 421a and 421b are individually provided in the first and second drug supply units 42a and 42b, the supply amount of slaked lime to the drug supply position P1 and the slaked lime to the auxiliary supply position P2 The supply amount can be changed with a higher degree of freedom than the exhaust gas treatment device 4 of FIG. 2 (the same applies to the supply amount of the special auxiliary agent). In the preferred exhaust gas treatment device 4, the supply amount of slaked lime by the first chemical supply unit 42a is larger than the supply amount of slaked lime by the second chemical supply unit 42b in normal times. 2, the chemical supply position P1 may be set upstream of the temperature reducing tower 41 in the flue 3 in the exhaust gas treatment device 4 of FIG. In the exhaust gas treatment device 4 of FIG. 2, the chemical supply position P <b> 1 may be set in the temperature reducing tower 41.

  Also in the exhaust gas treatment apparatus 4 of FIG. 5, the HCl concentration is reduced by controlling both the first chemical supply unit 42 a and the second chemical supply unit 42 b based on the HCl concentration acquired by the HCl concentration measurement unit 401. It is possible to appropriately cope with an abnormality that exceeds a predetermined value. In the exhaust gas treatment device 4, a certain amount of exhaust gas treatment chemical is supplied to the chemical supply position P1 by the first chemical supply unit 42a, and only the supply amount of the exhaust gas treatment chemical to the auxiliary supply position P2 by the second chemical supply unit 42b is HCl. It may be controlled based on the concentration. Also in this case, the supply amount of the exhaust gas treatment chemical to the auxiliary supply position P2 by the second chemical supply unit 42b is increased more than when the HCl concentration is less than the predetermined value at an abnormal time when the HCl concentration is equal to or higher than the predetermined value, It becomes possible to deal appropriately.

  Further, a certain amount of exhaust gas treatment chemical is supplied to the auxiliary supply position P2 by the second chemical supply unit 42b, and only the supply amount of the exhaust gas treatment chemical to the chemical supply position P1 by the first chemical supply unit 42a is based on the HCl concentration. It may be controlled. Also in this case, the first chemical supply is performed when the HCl concentration is less than the predetermined value while supplying the exhaust gas treatment chemical to the auxiliary supply position P2 by the second chemical supply unit 42b at the time of an abnormality in which the HCl concentration becomes a predetermined value or more. The supply amount of the exhaust gas treatment chemical to the chemical supply position P1 by the unit 42a can be increased to appropriately cope with it. In the exhaust gas treatment device 4 in which the first drug supply unit 42a and the second drug supply unit 42b include a drug storage unit, the first drug supply unit 42a and the second drug supply unit 42b are in an abnormal state when the HCl concentration becomes a predetermined value or more. While the exhaust gas treatment chemicals are supplied by both of them, the sum of the supply amounts of the exhaust gas treatment chemicals by both is increased as compared with the normal time when the HCl concentration is less than the predetermined value. This makes it possible to stabilize the HCl concentration in the exhaust gas (the same applies to the exhaust gas treatment device 4 in FIG. 2).

(Third embodiment)
FIG. 6 is a view showing an exhaust gas treatment device 4 according to the third embodiment of the present invention. In the exhaust gas treatment device 4 of FIG. 6, a dust collection ash transport unit 44 is provided instead of the second chemical supply unit 42 b in the exhaust gas treatment device 4 of FIG. 5, and the temperature of the chemical supply position P <b> 1 is reduced in the flue 3. It is set upstream of the tower 41.

  The dust collection ash transport unit 44 includes an auxiliary path 441, a dust collection ash distribution unit 45, a dust collection ash storage unit 442, a quantitative supply unit 443, a supply conveyor 46, and a chute unit 444. The auxiliary path 441 connects the position between the temperature reducing tower 41 and the dust collector 43 in the flue 3 (that is, the auxiliary supply position P <b> 2) and the lower portion of the dust collector 43. In FIG. 6, the auxiliary path 441 is indicated by a thin solid line. The auxiliary path 441 is a path different from the flue 3. In the auxiliary path 441, a dust collection ash distribution unit 45, a dust collection ash storage unit 442, a fixed amount supply unit 443, a supply conveyor 46, and a chute unit 444 are provided in order from the dust collector 43 toward the auxiliary supply position P2.

  The dust collection ash distribution unit 45 collects the fly ash and exhaust gas treatment chemicals (hereinafter collectively referred to as “dust collection ash”) that have been removed from the filter cloth in the dust collector 43 and the dust collection ash storage unit 442 and the dust collection unit. Distribute and supply to the ash treatment unit 49. Specifically, the dust collection ash distribution unit 45 includes a conveyor 451 and a gate 452. The conveyor 451 is, for example, a flight conveyor (also called a scraper conveyor). The gate 452 is provided in the dust collection ash conveyance path by the conveyor 451. When the amount of dust collection ash stored by the level meter (not shown) in the dust collection ash storage unit 442 is less than a predetermined amount, the gate 452 is opened and the dust collection ash is supplied to the dust collection ash storage unit 442. Is done. When the amount of dust collection ash stored in the dust collection ash storage unit 442 is greater than or equal to a predetermined amount, the gate 452 is closed and the dust collection ash is supplied to the dust collection ash processing unit 49. Thus, in the dust collection ash distribution unit 45, the dust collection ash from the dust collector 43 is collected by opening and closing the gate 452 so that the amount of dust collection ash stored in the dust collection ash storage unit 442 is approximately constant. It is distributed to the storage unit 442 and the dust collection ash processing unit 49.

  A fixed amount supply unit 443 is attached to the lower part of the dust collection ash storage unit 442. The fixed amount supply unit 443 is, for example, a table feeder, and takes out a set amount of dust collection ash from the dust collection ash storage unit 442 per unit time. The fixed amount supply unit 443 is connected to the supply conveyor 46, and the dust collection ash taken out from the dust collection ash storage unit 442 is supplied into the supply conveyor 46. The supply conveyor 46 is a flight conveyor, for example, and conveys the dust collection ash along a conveyor conveyance path from below the dust collection ash storage unit 442 to above the auxiliary supply position P <b> 2 in the flue 3. The conveyor conveyance path is a part of the auxiliary path 441 described above. The chute part 444 is provided above the auxiliary supply position P2, and the dust collection ash conveyed by the supply conveyor 46 is supplied to the auxiliary supply position P2 via the chute part 444. As described above, the dust collection ash contains the exhaust gas treatment chemical. Therefore, it can be said that the dust collection ash transport unit 44 is a second chemical supply unit capable of supplying an exhaust gas treatment chemical containing slaked lime to the auxiliary supply position P2.

  The control of the first chemical supply unit 42a and the dust collection ash transport unit 44 by the control unit 40 is the same as the control for the first chemical supply unit 42a and the second chemical supply unit 42b in the exhaust gas treatment device 4 of FIGS. is there. Therefore, when the HCl concentration is equal to or higher than the predetermined value, the supply amount of the dust collection ash to the auxiliary supply position P2 by the dust collection ash transport unit 44 is increased more than when the HCl concentration is less than the predetermined value. Alternatively, when the HCl concentration is equal to or higher than the predetermined value, the first chemical supply unit 42a is supplied more than when the HCl concentration is less than the predetermined value while supplying the dust collection ash to the auxiliary supply position P2 by the dust collection ash transport unit 44. The amount of the exhaust gas treatment chemical supplied to the chemical supply position P1 is increased.

  As described above, in the exhaust gas treatment device 4 of FIG. 6, the unused exhaust gas treatment chemical is supplied to the chemical supply position P1 between the combustion chamber 2 and the temperature reducing tower 41 by the first chemical supply unit 42a. . Thereby, in normal time, desalination performance can be improved by using slaked lime efficiently. Further, the dust collection ash transport unit 44 supplies dust collection ash containing slaked lime to the auxiliary supply position P2. Thus, by using the dust ash collected by the dust collector 43 as the exhaust gas treatment chemical, the amount of exhaust gas treatment chemical used in the first chemical supply unit 42a (that is, the exhaust gas treatment chemical in which fly ash is not mixed) Use amount) can be reduced. In addition, when the HCl concentration becomes a predetermined value or more, the first chemical supply unit 42a supplies the exhaust gas treatment chemical by the first chemical supply unit 42a and supplies the dust collection ash by the dust collection ash transport unit 44. Both or one of the supply amount of the exhaust gas treatment chemical by and the supply amount of dust collection ash by the dust collection ash transport unit 44 is increased from the normal time when the HCl concentration is less than a predetermined value. Thereby, it is possible to appropriately cope with an abnormality.

  In the dust collection ash transport unit 44, the dust collection ash may be transported to the auxiliary supply position P2 using a carrier gas such as air. Further, in the exhaust gas treatment device 4 of FIG. 6, the chemical supply position P1 may be set in the temperature reduction tower 41, and the exhaust gas treatment chemical may be supplied into the temperature reduction tower 41 by the first chemical supply unit 42a (described later). The same applies to the exhaust gas treatment device 4 of FIGS. 7 and 8).

(Fourth embodiment)
FIG. 7 is a view showing an exhaust gas treatment device 4 according to the fourth embodiment of the present invention. In the exhaust gas treatment device 4 of FIG. 7, the auxiliary supply position P <b> 2 in the exhaust gas treatment device 4 of FIG. 6 is upstream of the temperature reduction tower 41 in the flue 3, that is, between the combustion chamber 2 and the temperature reduction tower 41. Is set. Other configurations are the same as those of the exhaust gas treatment apparatus 4 of FIG. 6, and the same components are denoted by the same reference numerals.

  Also in the exhaust gas treatment device 4 of FIG. 7, when the unused exhaust gas treatment chemical is supplied to the chemical supply position P1 between the combustion chamber 2 and the temperature reducing tower 41 by the first chemical supply unit 42a, In this case, desalting can be performed efficiently. Moreover, dust collection ash conveyance part 44 reduces the usage-amount of the waste gas processing chemical | medical agent in the 1st chemical | medical agent supply part 42a by supplying the dust collection ash containing slaked lime to the flue 3 as a 2nd chemical | medical agent supply part. Can do. Further, at the time of abnormality when the HCl concentration becomes a predetermined value or more, both or one of the supply amount of the exhaust gas treatment chemical by the first chemical supply unit 42a and the supply amount of the dust collection ash by the dust collection ash transport unit 44 are changed to the HCl concentration. Is increased from the normal time when it is less than the predetermined value, it is possible to appropriately cope with an abnormal time. As described with reference to FIG. 2 and FIG. 5 to FIG. 7, from the viewpoint of suppressing a rapid increase in the HCl concentration at an abnormal time when the HCl concentration exceeds a predetermined value, the auxiliary supply position P2 On the road 3, it is only necessary to be provided between the combustion chamber 2, which is a source of exhaust gas, and the dust collector 43.

(Fifth embodiment)
FIG. 8 is a view showing an exhaust gas treatment device 4 according to the fifth embodiment of the present invention. In the exhaust gas treatment apparatus of FIG. 8, two auxiliary supply positions P <b> 2 are set in the dust collection ash transport unit 44. One auxiliary supply position P <b> 2 is between the combustion chamber 2 and the temperature reduction tower 41 in the flue 3, and the other auxiliary supply position P <b> 2 is between the temperature reduction tower 41 and the dust collector 43.

  In the dust collection ash transport unit 44 of FIG. 8, a supply conveyor 47 and a chute unit 445 are added to the dust collection ash transport unit 44 of FIG. The supply conveyor 47 is connected to a predetermined position of the supply conveyor 46, and continues from the position above the one auxiliary supply position P2. Thus, dust ash can be supplied to the one auxiliary supply position P <b> 2 using a part of the supply conveyor 46, the supply conveyor 47 and the chute 445. Dust ash can be supplied to the other auxiliary supply position P <b> 2 using the supply conveyor 46 and the chute 444. Also in the exhaust gas treatment device 4 of FIG. 8, the dust collection ash transport unit 44 supplies the dust collection ash containing slaked lime to the flue 3 as the second chemical supply unit, whereby the exhaust gas treatment in the first chemical supply unit 42a. The amount of medicine used can be reduced. Further, at the time of an abnormality in which the HCl concentration becomes a predetermined value or more, both or one of the supply amount of the exhaust gas treatment chemical by the first chemical supply unit 42a and the supply amount of the dust collection ash by the dust collection ash transport unit 44 are increased. Therefore, it is possible to cope with it appropriately.

(Modification)
Various modifications are possible in the embodiment of the exhaust gas treatment apparatus.

  The HCl concentration measurement unit 401 may be provided in the flue 3 between the temperature reducing tower 41 and the dust collector 43 (for example, at the inlet of the dust collector 43), or may be provided between the dust collector 43 and the chimney 52. . The chimney 52 is usually provided with another HCl concentration measurement unit. However, by providing the HCl concentration measurement unit 401 on the upstream side of the chimney 52, it is possible to quickly cope with fluctuations in the HCl concentration of the exhaust gas. Become. Or supply_amount | feed_rate of waste gas processing chemical | medical agent may be controlled using the HCl concentration measurement part provided in the chimney 52 (it may be taken as a part of flue).

  The exhaust gas treatment device 4 may be used in facilities other than the incineration facility 1.

  The configurations in the above-described embodiments and modifications may be combined as appropriate as long as they do not contradict each other.

  Although the invention has been illustrated and described in detail, the foregoing description is illustrative and not restrictive. Therefore, it can be said that many modifications and embodiments are possible without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Incinerator 2 Combustion chamber 3 Flue 4 Exhaust gas treatment apparatus 40 Control part 41 Temperature-reduction tower 42a 1st chemical | medical agent supply part 42b 2nd chemical | medical agent supply part 43 Dust collector 44 Dust collection ash conveyance part 401 HCl concentration measurement part 421 Slaked lime storage part P1 Drug supply position P2 Auxiliary supply position S11 to S13 Steps

Claims (5)

An exhaust gas treatment device,
A dust collector installed in a flue through which exhaust gas flows;
A temperature reducing tower that is provided between the generation source of the exhaust gas and the dust collector in the flue, and sprays water into the exhaust gas;
An exhaust gas treatment chemical containing a calcium-based chemical is supplied to the chemical supply position with the position between the generation source and the temperature reduction tower in the flue or the position in the temperature reduction tower as a chemical supply position. A first drug supply unit;
A second chemical supply unit capable of supplying an exhaust gas treatment chemical containing a calcium-based chemical to an auxiliary supply position between the generation source and the dust collector in the flue;
An HCl concentration measuring unit for measuring the HCl concentration in the exhaust gas;
When the HCl concentration is equal to or higher than a predetermined value, the supply amount of the exhaust gas treatment chemical to the auxiliary supply position by the second chemical supply unit is increased than when the HCl concentration is less than the predetermined value, or When the HCl concentration is equal to or higher than a predetermined value, the first chemical supply unit supplies the exhaust gas treatment chemical to the auxiliary supply position while the HCl concentration is lower than the predetermined value. A control unit for increasing the supply amount of the exhaust gas treatment chemical to the chemical supply position by the chemical supply unit;
Is provided. The exhaust gas treatment apparatus according to claim 1,
The first drug supply unit and the second drug supply unit share a storage unit that stores a calcium-based drug. The exhaust gas treatment apparatus according to claim 1 or 2,
The second chemical supply unit supplies dust ash collected by the dust collector as the exhaust gas treatment chemical. Incineration equipment,
A combustion chamber for burning waste,
A flue for discharging exhaust gas generated in the combustion chamber from the combustion chamber;
The exhaust gas treatment device according to any one of claims 1 to 3, provided in the flue,
Is provided. An exhaust gas treatment method in an exhaust gas treatment device,
The exhaust gas treatment device is
A dust collector installed in a flue through which exhaust gas flows;
A temperature reducing tower that is provided between the generation source of the exhaust gas and the dust collector in the flue, and sprays water into the exhaust gas;
An exhaust gas treatment chemical containing a calcium-based chemical is supplied to the chemical supply position with the position between the generation source and the temperature reduction tower in the flue or the position in the temperature reduction tower as a chemical supply position. A first drug supply unit;
A second chemical supply unit capable of supplying an exhaust gas treatment chemical containing a calcium-based chemical to an auxiliary supply position between the generation source and the dust collector in the flue;
With
The exhaust gas treatment method comprises:
a) supplying the exhaust gas treatment chemical by the first chemical supply unit into the temperature reduction tower at a position between the generation source and the temperature reduction tower in the flue;
b) measuring the HCl concentration in the exhaust gas;
c) When the HCl concentration is equal to or higher than a predetermined value, the supply amount of the exhaust gas treatment chemical to the auxiliary supply position by the second chemical supply unit is increased more than when the HCl concentration is less than the predetermined value. Or, when the HCl concentration is equal to or higher than a predetermined value, the second chemical supply unit supplies the exhaust gas treatment chemical to the auxiliary supply position while the HCl concentration is lower than the predetermined value. Increasing the supply amount of the exhaust gas treatment chemical to the chemical supply position by the first chemical supply unit;
Is provided.

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