JP6161309B2 - Exhaust gas treatment apparatus and treatment method using the same - Google Patents

Description

  The present invention relates to an exhaust gas treatment device and a treatment method using the same, and more particularly to an exhaust gas treatment device used for cleaning exhaust gas discharged from combustion equipment such as incineration equipment such as waste and a treatment method using the same. .

  In combustion exhaust gas discharged from waste incineration facilities that incinerate wastes such as various types of waste, iron manufacturing, metallurgy, or cement manufacturing facilities, many harmful substances including fine particles, NOx and other harmful substances and trace amounts Organic compounds are present. Among organic compounds, dioxins represented by polychlorinated dibenzodioxins, polychlorinated dibenzofurans, and coplana PCBs are harmful substances to the human body, and exhaust gas treatment equipment or treatment that removes these from exhaust gas together with dust, NOx, etc. A method is required, and many processing apparatuses and processing methods have been put into practical use.

  For example, there has been proposed an exhaust gas treatment method in which dust removal processing in waste gas and oxidative decomposition treatment of organic compounds such as dioxin are simultaneously performed by a gas dust collector incorporating a plurality of gas dust collection filters. Specifically, as shown in FIG. 6, the high-temperature exhaust gas 129 from a waste incinerator or the like having a combustion chamber and a sub-combustion chamber is in the range of 150 to 400 ° C., preferably 150 to 350 ° C. in the cooling device 130. As the ash is removed by the gas dust collector 128 according to the present invention, organic compounds such as dioxins are oxidatively decomposed and made harmless, and the suction fan 131 releases the air from the chimney 132 (for example, patent) Reference 1).

JP 2004-033855 A

However, the above-described prior art exhaust gas treatment apparatus or treatment method has various problems depending on various components contained in the exhaust gas. In particular, dust treatment in exhaust gas has many problems including the cost of removal / recovery treatment because it has various properties in terms of quantity and quality. In particular,
(I) When a filtration type dust collector (bag filter) is used to remove dust in the exhaust gas, the dust collection performance is good, but the power consumption (power consumption of the blower) is large due to the large pressure loss. In order to solve this, it is conceivable to increase the number of times the dust attached to the filter cloth is removed. However, the deterioration of the filter cloth is accelerated, the replacement frequency is increased, and it is economically lost.
(Ii) In addition, frequent reverse blow (blowback or pulse jet) by compressed air to remove dust adhering to the filter cloth increases the amount of compressed air used, increasing the equipment cost, There is no effect of greatly reducing the pressure loss in the bag filter (for example, 1/2 or less).
The problem is mentioned.

  Therefore, in view of the above-described problems of the prior art, the object of the present invention is to perform dust treatment using a simple method, and thus in an exhaust gas generated from a combustion facility without requiring a complicated and costly configuration. To provide an easy-to-use and effective exhaust gas cleaning process, a labor-saving exhaust gas treatment apparatus with high energy efficiency, and a treatment method using the same. is there.

  As a result of intensive studies, the present inventor has found that the above object can be achieved by an exhaust gas treatment device and a treatment method using the exhaust gas treatment device described below, and has completed the present invention.

That is, the present invention includes a chemical introduction part for introducing a chemical (neutralizing agent) for neutralizing an acidic gas component in exhaust gas generated from combustion equipment into which a combustion object is introduced into the exhaust gas, and neutralization An exhaust gas treatment comprising: a dust collector , wherein treated exhaust gas is introduced, and fly ash generated by combustion of the combustion object contained in the exhaust gas and / or a reaction product generated by neutralization treatment In the apparatus, each processing unit in which exhaust gas is processed until a phosphorus injection unit responsible for supplying phosphorus or a phosphorus compound is transferred from the combustion facility to the dust collector, including the combustion facility, and the exhaust gas It is provided in any or some of the flow paths, and is characterized in that the phosphorus or phosphorus compound is introduced.

In the dust removal process in the exhaust gas treatment apparatus, there are some problems as described above. In the verification process, the inventor
(A) When phosphorus or phosphorus compounds (hereinafter collectively referred to as “phosphorus compounds”) exist in the combustion furnace, ash (Si, Al, Ca, etc.) in the exhaust gas discharged from the combustion furnace is the main component. (B) When the average particle size of the dust in the exhaust gas is large, the pressure loss in a filtering dust collector such as a bag filter can be greatly reduced (c) In the exhaust gas flow channel downstream of the phosphorus compound injection, there is little adhesion of dust etc. to the surface of the flow channel, preventing the occurrence of sticking matter, corrosion due to corrosive substances, blockage of the flow channel due to product growth, etc. (D) In the case of further verification, the same applies to the case where a phosphorus compound is introduced into the neutralization processing section provided on the downstream side of the combustion furnace or the filtration-type dust collector on the further downstream side. It found that it is possible to reduce the pressure loss in the dust collector. The present invention is based on such knowledge, and by injecting a phosphorus compound into the treatment system in a predetermined exhaust gas treatment process, pressure in removing dust from the exhaust gas without requiring a complicated and expensive equipment configuration. It has become possible to provide an exhaust gas treatment apparatus that can prevent loss increase and the like, enable simple and effective exhaust gas purification treatment, save labor, and have high energy efficiency. In addition,
(E) It has the effect of suppressing the generation of dioxins, which is a problem particularly in the combustion process of waste. (F) It has the effect of suppressing the elution of heavy metals contained in the waste, which is a problem in the exhaust gas treatment process. It has been found that such a process, which has previously required a very complicated and expensive equipment configuration, can be performed more simply and effectively by the configuration according to the present invention.

The present invention is the above-described exhaust gas treatment apparatus, wherein the dust collector is provided with a pressure measuring device, and a pressure loss of a predetermined amount of exhaust gas introduced into and delivered to the dust collector is measured, and the measurement result is used. The amount of the phosphorus or phosphorus compound introduced is controlled.
As described above, in the exhaust gas treatment system according to the present invention, an increase in pressure loss due to dust in the exhaust gas can be very effectively prevented by injecting the phosphorus compound. At this time, as described later, there is a possibility that the effect can be further increased by injecting a predetermined amount of the phosphorus compound, and the effect also varies depending on the property of the combustion object such as the property of the waste. The knowledge that it was possible was also obtained. The present invention makes it possible to function the exhaust gas treatment effect having such a variable element more effectively by controlling the injection amount of the phosphorus compound based on the actually measured pressure loss amount.

The present invention provides an exhaust gas treatment apparatus as described above, wherein waste containing phosphorus or a phosphorus compound (hereinafter referred to as “phosphorous waste”) is used as the phosphorus or phosphorus compound, and the phosphorus concentration in the phosphorus waste is set in advance. Measure and control the amount of phosphorus waste introduced.
In recent years, phosphorus compounds, including organic phosphorus, have been used in many fields, and as a result, the amount of phosphorus waste discharged has increased and is easily available. In addition, the types and amounts of phosphorus compounds that can be combusted are increasing. For example, a fertilizer waste liquid, sludge, etc. can be mentioned. The present invention makes it possible to eliminate the need to prepare a new phosphorus compound by treating the phosphorus compound useful for reducing the pressure loss in the exhaust gas treatment with such phosphorus waste. Effective utilization of phosphorus waste that has been subjected to waste liquid treatment can be promoted, and its usefulness can be enhanced. Furthermore, such exhaust gas treatment can be performed under optimum conditions by controlling the amount of phosphorus waste introduced whose phosphorus concentration is measured in advance.

The present invention, in any one of the aforementioned exhaust gas treatment method from combustion equipment which uses exhaust gas treatment apparatus, during operation of the combustion equipment,
(1) A step of introducing exhaust gas supplied from the combustion facility into a boiler or boiler and a economizer to absorb waste heat. (2) An exhaust gas supplied from the boiler or boiler and economizer is used as a temperature reducing tower. the dispensing by exhaust gas from step (3) the reduced cooling tower for the introduction quenched treatment, the addition of neutralizing agent, the step of performing the neutralization process (4) is the neutralized treated flue gas, the dust The process of introducing dust into the equipment
(4a) A step of providing a pressure measuring device in the dust collector and measuring a pressure loss of a predetermined amount of exhaust gas introduced into and delivered to the dust collector (5) of the combustion equipment, (1) to (4) A step of introducing a predetermined amount of phosphorus or a phosphorus compound into any or some of the dust collectors
(5b) A step of controlling the amount of phosphorus or phosphorus compound introduced using the measurement result obtained in the step (4a). (6) An exhaust gas supplied from the dust collector is introduced into a denitration device. Step (7) of performing a treatment The method includes a step of discharging the exhaust gas supplied from the denitration apparatus as a purified gas.
In the purification process of exhaust gas discharged from combustion facilities, the separation and removal process of dust plays an important role, and reducing the load on the treatment system maintains a stable exhaust gas treatment over the long term. It is indispensable to do. The present invention uses the exhaust gas treatment apparatus having the excellent functions as described in the above (a) to (f), thereby removing dust in the exhaust gas without requiring a complicated and costly configuration at the installation site. An increase in pressure loss in the treatment can be prevented, and a simple and effective exhaust gas cleaning treatment can be performed, and labor saving and an energy efficient exhaust gas treatment method can be provided.

The present invention is the above exhaust gas treatment method, wherein in the step (5),
(5a) A step of measuring phosphorus concentration in phosphorus or phosphorus compound to be introduced in advance
(5c) The method includes the step of controlling the amount of the phosphorus or phosphorus compound introduced using the measurement result obtained in the step (5a).
With such a configuration, the exhaust gas treatment effect having variable factors such as the properties of waste functions more effectively, and the exhaust gas treatment can be performed under the optimum conditions.

Explanatory drawing which shows the exhaust gas processing apparatus which concerns on one Embodiment of this invention. Explanatory drawing which shows the 2nd structural example of the waste gas processing apparatus which concerns on this invention. Explanatory drawing illustrating the change in differential pressure when switching from normal operation to phosphoric acid waste liquid spray treatment Explanatory diagram illustrating the variation in the differential pressure of the bag filter due to the injection amount of the phosphorus compound Explanatory diagram illustrating the variation in differential pressure due to the amount of exhaust gas introduced into the bag filter Explanatory drawing illustrating an exhaust gas treatment apparatus according to the prior art

  An exhaust gas treatment apparatus according to the present invention (hereinafter referred to as “the present apparatus”) includes a chemical introduction unit that introduces chemicals for neutralizing acidic gas components in exhaust gas generated from combustion facilities into exhaust gas, And a dust collector for treating fly ash and / or reaction products, and including a phosphorus injection part for taking out phosphorus or a phosphorus compound (phosphorus compound) and a combustion facility, and transferring from the combustion facility to the dust collector It is provided in any or some of each processing part and its exhaust gas flow path in which exhaust gas is processed until it is carried out, and this phosphorus or phosphorus compound is introduced. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<One embodiment of the present apparatus (first configuration example)>
An outline of one embodiment of the present apparatus is shown in FIG. 1 (first configuration example). In the following description of the present apparatus, a configuration in which the phosphorus injection part 11 is provided in the combustion facility 1 will be described as an example. This apparatus is supplied from a combustion facility 1 in which a combustion target M such as waste is introduced from a waste input hopper 7 and a predetermined amount of a phosphorus compound P is introduced through a phosphorus injection part 11, and the combustion facility 1. From the boiler 2a and the economizer 2b in which the exhaust gas is introduced and the waste heat is absorbed, the temperature reducing tower 3 in which the exhaust gas delivered from the economizer 2b is introduced and subjected to a rapid cooling treatment, and the temperature reducing tower 3 Neutralization treatment unit 4 in which the exhaust gas supplied is introduced and neutralized by the neutralizing agent introduced from the drug introduction unit 41, and dust collection in which the exhaust gas subjected to the neutralization treatment is introduced and dust removal is performed The apparatus 5 and the chimney part 6 where the exhaust gas supplied from the dust collector 5 is discharged as a purified gas are provided. Here, a configuration in which the boiler 2a and the economizer 2b are arranged in series is illustrated, but a configuration that meets the specifications, such as when only a boiler is arranged, is possible.

  Hereinafter, a case where a predetermined amount of the phosphorus compound P is introduced into the combustion facility 1 in which the combustion object M includes the waste charging hopper 7 will be exemplified. It is possible to prevent an increase in pressure loss or the like in the dust removal process of the exhaust gas, enable a simple and effective exhaust gas cleaning process, save labor, and configure an exhaust gas treatment apparatus with high energy efficiency. In addition, this apparatus is not limited to such a structure, for example, the structure etc. which added the denitration apparatus (not shown) in which the waste gas supplied from the dust collector 5 is introduce | transduced, and a denitration process is performed are added. It is possible to apply a configuration (not shown) corresponding to a request for properties of the object M, legal regulations, etc., or use of valuable materials generated in the exhaust gas treatment process.

In the combustion facility 1, the combustion target M is burned together with the phosphorus compound P injected via the phosphorus injection section 11, and the generated incineration residue S is discharged from the lower part and the generated exhaust gas is discharged from the upper part. The combustion object M introduced into the combustion facility 1 is combusted by preheated auxiliary combustion air (not shown), converted into a gaseous component such as CO ₂ or H ₂ O, and includes unburned components. A solid component is generated. A large solid component is generated and fine solid particles are generated as dust (fine dust) floating in the exhaust gas. A large solid component forms an incineration residue or the like S and is discharged from the lower part of the combustion facility 1. At this time, it is presumed that when a predetermined amount of the phosphorus compound P is introduced through the phosphorus injection part 11, fine dust aggregates and particles of a predetermined size are formed. Details will be described later. Examples of the combustion facility 1 include a stoker type, hearth type or fluidized bed type incinerator or an incinerator such as a rotary kiln when the combustion object M is waste.

  A plurality of water pipes (not shown) are generally provided in the boiler 2a and the economizer 2b, and the temperature of the exhaust gas delivered from the combustion facility 1 by heat exchange with water flowing through the water pipe. Is cooled to about 150-300 ° C. The heated water is used for boiler water and the like.

  In the temperature reducing tower 3, cooling water is injected into the exhaust gas flow path, the temperature of the exhaust gas is rapidly taken away by the latent heat of evaporation of the water, and the temperature of the exhaust gas is cooled to about 200 ° C. or less and about 100 to 200 ° C. Thereby, it is possible to reduce a load in a subsequent process such as a dust collector.

  In the neutralization process part 4, the neutralization process is performed with respect to the waste gas delivered from the temperature-reduction tower 3. FIG. Specifically, by injecting a chemical (neutralizing agent) N containing an alkali component such as slaked lime into the exhaust gas, the exhaust gas containing a large amount of acidic components such as sulfur oxides, chlorine compounds, and carbonates is neutralized. Be rendered harmless. In addition, the neutralizing agent N is not limited to these, For example, if it is a chemical | medical agent which has alkalinity, such as the regenerated alkali processing liquid and produces | generates a harmless compound after reaction, this can be used. In addition, it is not necessary to provide a special reaction tank as the neutralization processing unit 4, and the exhaust gas flow path from the preceding temperature reduction tower 3 to the subsequent dust removing device 5 or the dust collection processing such as the filter medium in the dust removing device 5 is performed. It is sufficient if neutralization can be performed in the space.

  In the dust collector 5, the dust removal process of the fine dust containing the aggregate in the neutralized exhaust gas is performed. As the dust collector 5, a bag filter (filter type dust collector) or the like can be used. The injection treatment of the phosphorus compound P in this apparatus can obtain a higher technical effect in reducing the pressure loss in the dry type, particularly the filtration type dust collection process such as a bag filter. Fine particles collected in the bag filter are discharged from the bottom as dust D

  In the chimney 6, the exhaust gas delivered from the dust collector 5 is fed by the feed fan F and discharged as a cleaned gas E.

[Injection of phosphorus compounds]
In this apparatus, the phosphorus compound P is injected by, for example, liquid phosphorus compound such as fertilizer waste liquid, granular phosphorus compound such as phosphorus pentoxide, or phosphorus waste such as sludge from the combustion facility 1 or the combustion facility 1 to the dust collector 5. It is preferable that the exhaust gas is introduced into any one or some of the processing units 2 to 5 and the exhaust gas flow paths in which the exhaust gas is processed before being transferred. In particular, as a knowledge of the verification process, it is preferable that the gas is introduced into the combustion facility 1 and injected so as to be dispersed in the exhaust gas generated by the combustion of the combustion object M. Specifically, by providing the phosphorus injection part 11 at a position where it can be added directly from the upper part of the upper combustion object M of the combustion facility 1, the phosphorus injection part 11 can be dispersed over the entire combustion object M, and generated and increased by combustion. It can also be added to the exhaust gas forming the flow and can act on the aggregation of high temperature dust in the exhaust gas. Moreover, by providing it at a position where it can be added to the upper part of the flame from the burning combustion object M, it can act on the agglomeration of dust in a high-temperature combustion state, and also suppresses dioxin generation and heavy metal elution. Function can be expected.

  In the verification process, a high dust agglomeration effect is obtained by injecting the phosphorus compound under conditions of about 100 ° C. or higher. Therefore, in this apparatus, even if the injection operation of the phosphorus compound is performed in any of the boiler 2a, the economizer 2b, the temperature reducing tower 3, the neutralization processing unit 4 and the dust collector 5, a high dust agglomeration action, dioxin It can be expected to have a function of suppressing the generation of slag and a function of suppressing elution of heavy metals. Also, for example, by dispersing powdered phosphorus compound from the waste input hopper 7 to the waste, forming a state where the combustion object M and the phosphorus compound are mixed in advance, and then reacting in a high-temperature combustion state, High dust agglomeration action can be secured. Thus, the phosphorus injection part 11 includes the combustion equipment 1 and any of the processing parts 2 to 5 in which the exhaust gas is treated until it is transferred from the combustion equipment 1 to the dust collector 5 and its exhaust gas flow path. In some cases, by introducing a phosphorus compound, a high dust aggregating action, a dioxin generation suppressing function and a heavy metal elution suppressing function can be obtained.

  At this time, as a phosphorus compound, use phosphorous substance such as simple powder of phosphorus, phosphorus pentoxide, phosphoric acid solution such as orthophosphoric acid, hypophosphorous acid, phosphorous acid, or fertilizer waste liquid or sludge. Can do. Further, as will be described later, the ratio of combustion object to phosphorus (phosphorus concentration in the combustion product) affects the agglomeration action of the dust, so the injection amount of the phosphorus compound whose phosphorus concentration is measured in advance is controlled. Thus, such exhaust gas treatment can be performed under optimum conditions.

<Another configuration example of the present apparatus (second configuration example)>
Another embodiment of the present apparatus is shown in FIG. 2 (referred to as a second configuration example). A pressure measuring device A is provided in the dust collector 5 to measure the pressure loss of a predetermined amount of exhaust gas introduced and delivered to the dust collector 5. The increase in the pressure loss reduction effect due to dust in the exhaust gas in the present apparatus due to the injection of the phosphorus compound P can be confirmed. Moreover, it is preferable to control the introduction amount of the phosphorus compound P into the combustion facility 1 using such measurement results. By controlling the injection amount of the phosphorus compound P based on the actually measured pressure loss amount, the exhaust gas treatment effect that varies depending on the property of the combustion target M such as the property of the waste can be functioned more effectively.

<Exhaust gas treatment method using this device>
Next, the exhaust gas treatment process using this apparatus will be described in detail. When the combustion facility 1 and the exhaust gas treatment device are in operation, the following treatment process is provided.
(1) Step of introducing exhaust gas supplied from combustion equipment into boiler or boiler and economizer to absorb waste heat (2) Introducing exhaust gas supplied from boiler or boiler and economizer into temperature reduction tower (3) The step of quenching (3) The step of adding a neutralizing agent to the exhaust gas delivered from the temperature reducing tower and the step of neutralizing (4) The neutralized exhaust gas is introduced into the dust collector , A step of removing dust (5) A step of introducing a predetermined amount of phosphorus or a phosphorus compound into any one or some of the combustion equipment, the steps (1) to (4) and the dust collector (6) From the dust collector The step of introducing the exhaust gas supplied to the denitration apparatus and performing the denitration process (7) The step of discharging the exhaust gas supplied from the denitration apparatus as a purified gas will be described based on the first configuration example.

(1) Waste heat absorption process in boiler or boiler and economizer The exhaust gas discharged from the combustion facility 1 is introduced into the boiler 2a and economizer 2b. In the boiler 2a and the economizer 2b, heat is recovered so that the temperature of the exhaust gas is about 150 to 300 ° C. by a plurality of water pipes and the like through which a heat medium flows. The recovered heat is used for power generation or the like, and the temperature-reduced exhaust gas is introduced into the temperature-decreasing tower 3 and further cooled.

(2) Quenching treatment step in the temperature-decreasing tower The exhaust gas of about 150 to 300 ° C. discharged from the economizer 2 b is introduced into the temperature-decreasing tower 3. In the temperature-decreasing tower 3, it is rapidly cooled to 200 ° C. or less by, for example, jet cooling water or the like. By the exhaust gas cooling treatment, the efficiency of the subsequent neutralization treatment and dust removal treatment can be improved. The cooled exhaust gas is introduced into the neutralization processing unit 4 and neutralization is performed.

(3) Neutralization treatment process The exhaust gas of 200 ° C. or less discharged from the temperature reducing tower 3 is introduced into the neutralization treatment unit 4. In the neutralization process part 4, neutralizing agents N, such as slaked lime, are added from the chemical | medical agent introduction part 41, for example, and a neutralization process is performed. The neutralized exhaust gas is introduced into the dust removing device 5 including fine dust, neutral reaction products and unreacted neutralizing agent N, and further dust removal processing is performed.

(4) Dust removal processing step in the dust collector The exhaust gas discharged from the neutralization processing unit 4 is introduced into the dust removal device 5. For example, a bag filter is used as the dust remover 5 and a dust removal process using a filter cloth or the like is performed. Fine dust, neutral reaction products, and unreacted neutralizing agent N collected by the filter cloth and the like are backwashed and discharged after a predetermined time. The dust-exhausted exhaust gas is introduced into the chimney 6 as a purified exhaust gas and discharged, or if necessary, is introduced into a denitration apparatus to remove nitrogen oxides (NOx) in the exhaust gas. .

  At this time, it is preferable to include (4a) a step of measuring the pressure loss of a predetermined amount of exhaust gas introduced into and delivered to the dust collector 5. The dust collection function in the dust collector 5 is abruptly reduced when the pressure loss increases. When the pressure loss due to dust collected in the dust removing device 5 exceeds a predetermined value, the dust collecting function can be regenerated and maintained by backwashing the filter cloth or the like by blowback or the like. Moreover, it is preferable to have the process of controlling the introduction amount of the phosphorus compound P using the obtained measurement result. By controlling the injection amount of the phosphorus compound on the basis of the pressure loss in the dust collector 5 in the actual operation state, it is possible to perform such exhaust gas treatment under optimum conditions and to reduce processing operations such as blowback. .

(5) Phosphorus compound introduction process Combustion introduced into combustion equipment 1, any of the above-mentioned steps (1) to (4), dust collector 5 or some of them during operation of this apparatus including combustion equipment 1 A phosphorus compound P corresponding to the introduction amount of the object M is introduced from the phosphorus injection part 11. In the combustion facility 1, it is understood that a reaction product generated by combustion of the combustion object M or an unreacted component and the phosphorus compound P react to form agglomerates due to a physical bond. An exhaust gas of about 1000 to 1500 ° C. is generated by the reaction or the like.

At this time, (5a) a step of measuring the phosphorus concentration in the phosphorus compound P to be introduced in advance, and a step of controlling the amount of the phosphorus compound P introduced into the combustion facility 1 using the obtained measurement results, It is preferable to have. The dust agglomeration effect is affected by the ratio of combustion object to phosphorus (phosphorus concentration in the combustion product). By controlling the injection amount of the phosphorus compound whose phosphorus concentration is measured in advance, under optimum conditions, Such exhaust gas treatment can be performed.

(6) Denitration treatment step in the denitration device The exhaust gas discharged from the dust collector 5 may be immediately introduced into the chimney 6 and discharged as in the first configuration example. The case where it is introduced into a denitration apparatus (not shown) is also mentioned. Nitrogen oxide (NOx) in the exhaust gas introduced into the denitration device reacts with ammonia supplied to the denitration device in the presence of the denitration catalyst filled in the denitration device, and is denitrated. As the denitration catalyst, an existing supported catalyst or a mixed catalyst such as a transition metal oxide catalyst such as a V ₂ O ₅ —TiO ₂ catalyst, a platinum group oxidation catalyst, a catalyst combining these, etc. is used. Then, a denitration process is performed. The shape of the catalyst can be granular, pellet, honeycomb, etc. Select the honeycomb shape, pellet shape, etc. from the pressure loss, flow rate and flow rate of the exhaust gas introduced, the efficiency of the catalytic reaction, etc. Is preferred. Moreover, it is preferable to control the temperature of the denitration reaction to be 200 to 300 ° C.

(7) Discharge process The exhaust gas discharged from the dust collector 5 or the denitration device is introduced into the chimney 6. The gas purified by the above steps (1) to (6) is discharged by the feeding fan F through the chimney 6. Since such exhaust gas has been purified, it can be reused as blowback gas in the dust collector 5 or purge processing gas in each processing section.

<Verification experiment>
The phosphorus compound injection effect in this apparatus was tested using a production plant equivalent to the first configuration example.
(I) The following phosphorus compounds were injected into an incinerator operating under the operating conditions shown in Table 1 under the experimental conditions, and effects such as pressure loss of the bag filter were confirmed.
(I-1) A phosphoric acid waste solution obtained by neutralizing triethylamine (strong alkali) with a 75% aqueous solution of phosphoric acid (H ₃ P0 ₄ : strong acid) was used as the phosphorus compound.
(I-2) A 75% aqueous solution of phosphoric acid was prepared and used as a phosphorus compound under four conditions as shown in Table 2 below, including a diluted solution with water.

(Ii) Experimental Results FIG. 3 illustrates the change in the differential pressure when switching from normal operation to phosphoric acid waste liquid spray treatment. Moreover, it confirmed that there existed the following effects.
(Ii-1) After starting the phosphoric acid waste liquid spraying, the differential pressure of the bag filter began to gradually decrease, and as shown in Table 3 below, after about 1 hour, the pressure was reduced to about 2/5 compared with before the spraying started.
(Ii-2) the bag filter inlet dust concentration, usually to the driver when 0.8g ^/ m 3 N-dry, phosphoric acid waste liquid spray at 2.0g ^/ m 3 N-dry, and the at phosphate waste spray The operation state with higher dust concentration.
(Ii-3) When the dust collected in the bag filter was inspected, as shown in Table 4 below, the degree of aggregation was higher (dispersion degree is lower) when spraying phosphoric acid waste liquid than during normal operation. As the particle size distribution shown in Table 5 below, the particle size was large.
(Ii-4) The variation in the differential pressure of the bag filter is shown in Table 6 below. Under condition 1, the bag filter differential pressure suddenly decreased, under condition 2, the bag filter differential pressure gradually decreased, and under condition 3, the bag filter differential pressure began to increase. The level was falling. This result is illustrated in FIG. 4 as a variation in the differential pressure of the bag filter due to the injection amount of the phosphorus compound. With respect to the phosphoric acid concentration, the result that the effect of reducing the differential pressure (pressure loss) was increased from around 0.2%. FIG. 5 illustrates the variation in the differential pressure due to the amount of exhaust gas introduced into the bag filter. The effect by injection | pouring of a phosphorus compound can acquire a big effect with the increase in the exhaust gas introduction amount.
(Ii-5) After performing the phosphoric acid waste liquid spray treatment for a long time (2 days to 1 week), the inside of the exhaust gas flow channel inside each treatment section after the economizer 2b was confirmed. There was almost no adhesion etc., and it was in a very clear state.
(Ii-6) Dioxins in dust (fly ash) collected in the bag filter and the elution amount of lead, which is a heavy metal, were examined. As shown in Table 7 below, when phosphoric acid waste liquid was sprayed compared to normal operation The result was that the dioxin was reduced to about 2/3, and lead elution was not detected. Here, the content of dioxins was detected (by GC / MS) in Ministry of the Environment Notification No. 80 (2004), and the amount of lead elution was detected in Environment Agency Notification No. 13 (1973).

(Iii) Summary As described above, it has been demonstrated that injection of phosphorus compounds in this equipment prevents an increase in pressure loss during purification in exhaust gas, and enables simple and effective exhaust gas purification treatment. We were able to.

DESCRIPTION OF SYMBOLS 1 Combustion equipment 11 Phosphorus injection part 2a Boiler 2b Carbon-saving device 3 Temperature reduction tower 4 Neutralization process part 41 Chemical introduction part 5 Dust collector 6 Chimney part 7 Waste input hopper D Dust E Purified gas F Feeding fan M Combustion object N Neutralizer P Phosphorus compound (phosphorus or phosphorus compound)
S Incineration residue, etc.

Claims (4)

A chemical introduction section for introducing a chemical (neutralizing agent) for neutralizing acidic gas components in the exhaust gas generated from the combustion facility into which the combustion object is introduced into the exhaust gas, and a neutralized exhaust gas are introduced. A dust collector for treating fly ash generated by combustion of the combustion object contained in the exhaust gas and / or a reaction product generated by neutralization,
Each of the treatment parts and the exhaust gas flow paths in which the exhaust gas is treated until the phosphorus injection part responsible for supplying phosphorus or phosphorus compounds is transferred from the combustion equipment to the dust collector, including the combustion equipment. Or some provided, the phosphorus or phosphorus compound is introduced,
A pressure measuring device is provided in the dust collector, and the pressure loss of a predetermined amount of exhaust gas introduced into and delivered to the dust collector is measured, and the introduction amount of the phosphorus or phosphorus compound is controlled using the measurement result An exhaust gas treatment apparatus characterized by that.   As the phosphorus or phosphorus compound, waste containing phosphorus or phosphorus compound (hereinafter referred to as “phosphorous waste”) is used, and the phosphorus concentration in the phosphorus waste is measured in advance to control the amount of phosphorus waste introduced. The exhaust gas treatment apparatus according to claim 1. A processing method of an exhaust gas from combustion equipment which uses exhaust gas treatment apparatus according to claim 1 or 2, during operation of the combustion equipment,
(1) A step of introducing exhaust gas supplied from the combustion facility into a boiler or boiler and a economizer to absorb waste heat. (2) An exhaust gas supplied from the boiler or boiler and economizer is used as a temperature reducing tower. (3) Step of introducing a neutralizer into the exhaust gas supplied from the temperature reducing tower and performing neutralization treatment (4) Step of performing the neutralization treatment (4a) A step of measuring the pressure loss of a predetermined amount of exhaust gas introduced into and delivered to the dust collector (5) The combustion equipment , (1) to ( 4 ), a step of introducing a predetermined amount of phosphorus or a phosphorus compound into any or some of the dust collectors (5b) using the measurement result obtained in the step (4a) The amount of phosphorus or phosphorus compound introduced A step of controlling (6) a step of introducing the exhaust gas supplied from the dust collector into the denitration device and performing a denitration process (7) a step of discharging the exhaust gas supplied from the denitration device as a purified gas An exhaust gas treatment method comprising: In the step (5),
(5a) a step of measuring the phosphorus concentration in the phosphorus or phosphorus compound to be introduced in advance (5c) a step of controlling the amount of phosphorus or phosphorus compound introduced using the measurement result obtained in the step (5a) The exhaust gas treatment method according to claim 3.

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