JP5008507B2 - Dust collector having powder mixing processing means and powder mixing processing method - Google Patents

Description

  The present invention relates to a dust collector having a powder mixing processing means for handling ash particles generated after combustion and a powder mixing processing method.

  Coal is being reviewed as an alternative energy resource for oil. This is because coal has abundant reserves all over the world compared to oil, and a stable supply can be expected. Due to the influence of these reasons, various coal combustion facilities are on the rise. Of course, the number of coal-fired power plants is increasing, and coal combustion ash (hereinafter referred to as coal ash) as a by-product is also increasing rapidly. Coal ash is a powder, and especially coal ash called fly ash is already in a uniform spherical shape having a particle size of about 10 to 30 μm when collected. In general, a part of coal ash is effectively used as civil engineering and building materials such as concrete and soil improvement materials, and other surplus coal ash is used for landfill.

  The coal ash as described above contains a heavy metal (hazardous trace element) that is harmful even though it is a trace amount. Therefore, when coal ash is used for the above-mentioned purposes, measures are taken to reduce the elution concentration of harmful trace elements to a specified value or less in consideration of the environment. As a measure for suppressing the elution of harmful trace elements of coal ash, there is a method of insolubilizing heavy metals. The method of insolubilizing heavy metals is suitable for treating a large amount of coal ash. Specifically, a cement solidification method and a chemical treatment method are known. In the cement solidification method, cement or the like is added to coal ash and solidified to insolubilize heavy metals. In the chemical treatment method, an elution inhibitor such as a chelate compound is added to coal ash to insolubilize heavy metals.

  As described above, in the technology of contacting and reacting powders such as coal ash and additives such as cement and dissolution inhibitor, generally, coal ash, additives and moisture are charged into the reaction tank, In order to knead them, a stirrer is operated. The stirrer requires sufficient stirring time for bringing the powder and the additive into uniform contact and promoting the reaction, and requires a large amount of power. In addition, a corresponding reaction tank capacity is required, resulting in a batch reaction process.

On the other hand, as another prior art, a method of spraying a heavy metal immobilization material into exhaust gas and bringing it into contact with fly ash to immobilize the heavy metal contained therein is disclosed (for example, see Patent Document 1).
JP-A-9-108647

  As described above, uniform mixing of powder and additive is indispensable for the technology of contacting and reacting powder such as coal ash with additives such as cement and dissolution inhibitor. The smaller the amount of additive is relative to the amount of powder, the more difficult it is to uniformly mix the powder and additive. Therefore, this technology requires sufficient stirring power and time-consuming dedicated equipment and storage equipment, and the economic burden is great.

  On the other hand, the method of spraying a heavy metal immobilizing material in exhaust gas and bringing it into contact with fly ash in Patent Document 1 to immobilize the heavy metal contained therein is a facility for stirring powder and additives as described above. Etc. are not considered necessary. However, there is no description of what form is sprayed into the exhaust gas. Further, according to Patent Document 1, an effective immobilizing material is required exclusively for spraying in exhaust gas, bringing it into contact with fly ash, and enabling dust collection. Such an immobilizing material is not economically preferable because it requires a dedicated facility or is obtained at a considerable cost.

  This invention is made | formed in view of the above-mentioned subject, It raises to a state which is easier to use by mixing an additive with the dust represented by coal ash etc. which can be utilized effectively, suppressing cost. An object of the present invention is to provide a dust collector having a powder mixing processing means capable of performing the above and a powder mixing processing method using the same.

  In order to achieve the above-mentioned object, the present inventor pays particular attention to a coal ash dust collector, and after collecting particulate coal ash (fly ash) collected by the dust collector, mixes it with an additive at an earlier stage. As a result, the inventors have found the mixing treatment technology to be obtained and have completed the following invention.

  (1) a dust collection mechanism that has a chamber through which exhaust gas that has undergone predetermined combustion passes, collects dust contained in the exhaust gas, and transfers cleaner exhaust gas; and is provided below the dust collection mechanism, A sedimentation region in which the dust collected by the dust collection mechanism is accumulated in the direction of gravity by its own weight, an additive supply mechanism for supplying an additive for mixing with the dust, and the mixture of the dust and the additive to the outside A dust collector having a powder mixing processing means comprising an unloading control mechanism.

  According to the aspect of the invention described in (1), the dust collector is provided with the additive supply mechanism therein. Thereby, the dust collected by the dust collector can be mixed with the additive at an earlier stage. When taken out of the dust collector, the soot is raised to an accessible state by being more uniformly mixed with the additive.

  (2) In the dust collector having the powder mixing processing means according to (1), the exhaust gas is exhaust gas that has been burned with pulverized coal, the soot is spherical fine particles of ash, and the additive is included in the soot dust A dust collector having a powder mixing means comprising a substance having an ability to insolubilize the heavy metal when reacted with one or more heavy metals.

  According to the aspect of the invention described in (2), with respect to the aspect of (1), the spherical fine particles of coal ash and the additive that suppresses the elution of harmful trace elements in the coal ash are brought into contact in the dust collector. It contributes to the promotion of environmentally friendly treatment with a large amount of coal ash.

  (3) The dust collector having the powder mixing processing means according to (1) or (2), wherein the additive supply mechanism has a powder mixing processing means that is a mechanism for injecting the additive.

  According to the aspect of the invention described in (3), with respect to the aspect of (1) or (2), the additive is supplied and dust collected by being sprayed into the dust collector by using a spraying mechanism. Contacted and mixed with soot and dust, contributing to further reaction.

  (4) The dust collector having the powder mixing processing means according to (1) or (2), wherein the additive supply mechanism has a powder mixing processing means that is a mechanism for spraying the additive.

  According to the aspect of the invention described in (4), with respect to the aspect of (1) or (2), the additive is uniformly supplied into the dust collector by using a spraying mechanism, and dust is collected. It is contacted and mixed with and contributes to the promotion of the subsequent reaction.

  (5) A dust collector having the powder mixing processing means according to any one of (1) to (4), comprising a powder mixing processing means having a mechanism for collecting the additive in the dust collecting mechanism.

  According to the aspect of the invention described in (5), when the dust is collected by having a mechanism for collecting the additive in the dust collection mechanism, in any one of the aspects (1) to (4). To reach the sedimentation zone. Thereby, the dust is raised to a state where it can be easily used by being more uniformly mixed with the additive.

  (6) The dust collector having the powder mixing processing means according to any one of (1) to (5), wherein the additive supply mechanism has a powder mixing processing means having a mechanism for introducing air.

  According to the aspect of the invention described in (6), with respect to any one of aspects (1) to (5), air is introduced as an additive supply mechanism to obtain an additive transport medium. The additive is preferably powder and the air is preferably dry air. Thereby, an additive is efficiently supplied in a dust collector, minimizing the change of the environment in a dust collector.

  (7) A dust collector having the powder mixing processing means according to any one of (1) to (6), further comprising a powder mixing processing means further including a mixing mechanism at the bottom of the sedimentation region.

  According to the aspect of the invention described in (7), in addition to any one of the aspects (1) to (6), the dust and the additive accumulated in the sedimentation area by further providing a mixing mechanism at the bottom of the sedimentation area These mixtures can be mixed evenly.

  (8) a first dust collecting step in which soot dust contained in the exhaust gas is collected by the dust collector in a process in which the exhaust gas having undergone predetermined combustion passes through the dust collector and is transferred as clean exhaust gas; A second dust collecting step in which the dust collected by the dust collector is accumulated in the direction of gravity below the dust collector, and an additive is supplied into the dust collector, and the dust is collected in the second dust collecting step. A powder mixing treatment method comprising: a mixing step of mixing the additive and the additive; and an unloading step for unloading the mixture of the dust and the additive to the outside.

  According to the aspect of the invention described in (8), the dust collector is supplied with the additive therein, and the dust immediately after being collected and the additive can be mixed at an earlier stage. When taken out of the dust collector, the soot is raised to an accessible state by being more uniformly mixed with the additive.

  (9) The powder mixing method according to (8), wherein the mixing step uses air.

  According to the aspect of the invention described in (9), in the aspect described in (8), the mixing step introduces air as a carrier medium for the additive. The additive is preferably powder, and air is also preferably dry air. Thereby, an additive is efficiently supplied in a dust collector, minimizing the change of the environment in a dust collector. Moreover, you may utilize air so that it may act on mixing directly at the time of a 2nd dust collection process.

  (10) In the powder mixing method according to (8) or (9), the mixing step includes a step of collecting a predetermined amount of the additive by the dust collector in the first dust collection step. Body mixing treatment method.

  According to the aspect of the invention described in (10), with respect to the aspect described in (8) or (9), in the mixing step, a predetermined amount of additive is collected by the dust collector, and the dust is collected by the dust collector. When collected, it is mixed and collected with additives. This contributes to more uniform mixing of the dust and the additive and promotion of the subsequent reaction.

  According to the present invention, it is possible to carry out effective usable dust by mixing it with an additive at an early stage and making it easier to use while reducing the cost by adding as much as possible a large-scale facility. A dust collector having powder mixing processing means and a powder mixing processing method using the same can be provided.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments.

  FIG. 1 is a schematic configuration diagram showing a dust collector having powder mixing processing means according to the first embodiment of the present invention. The dust collector 100 is provided with a dust collecting mechanism 101 in a room through which exhaust gas that has passed through combustion of pulverized coal passes, such as a coal-fired boiler. As the dust collection mechanism 101, an electric dust collector that collects dust medium (coal ash) in exhaust gas with an electrode, a filter (bag filter) device that collects the dust with a filter cloth (filter cloth), or the like is applied. A dust collection hopper 102 is provided below the dust collection mechanism 101. The dust collection hopper 102 is a sedimentation region in which the dust collected by the dust collection mechanism 101 is removed by a predetermined impact or a brush in the dust collection mechanism 101 and accumulated in the gravity direction by its own weight. Such a dust collection mechanism 101 and dust collection hoppers 102 corresponding thereto are configured in a plurality of stages, and the following configuration is provided in one of the stages (a predetermined dust collection hopper 102 corresponding to the dust collection mechanism 101). Is described.

  For example, the additive supply mechanism 103 is provided with an additive supply port 103 a above the settling region of the dust collection hopper 102, and supplies the additive AD for mixing with the dust falling on the dust collection hopper 102. . The component of the additive AD is not particularly limited, but is preferably a powder (fine powder). As the additive AD, a substance that suppresses the elution of harmful trace elements such as boron, fluorine, selenium, arsenic, and hexavalent chromium contained in the coal ash may be selected as the dust AD, for example, coal ash. The additive AD at this time is an elution preventing agent containing, as a main component, at least one selected from the group consisting of calcium compounds such as limestone, slaked stone, and quicklime. An elution inhibitor selected from the group consisting of calcium compounds such as limestone, slaked stone, and quicklime is readily available at a relatively low cost, and includes harmful trace elements such as boron, fluorine, selenium, and arsenic. Elution can be effectively suppressed.

  The additive supply mechanism 103 is provided with a blow-through rotary valve 103b in order to supply the additive AD as described above, for example, above the dust collection hopper 102. The blow-through rotary valve 103 b is sprayed or sprayed on the additive AD that has moved to the supply port 103 a and is mixed with the dust falling on the dust collection hopper 102. Therefore, for example, the operation timing of the blow-through rotary valve 103b is preferably matched with the timing at which the dust collected from the dust collection mechanism 101 is removed. In addition, the carry-out control mechanism 104 controls the extraction of the mixture of the dust and the additive AD accumulated in the dust collection hopper 102 using a rotary valve or the like.

  According to the above configuration, the dust collector 100 is provided with the additive supply mechanism 103 therein. Thereby, the dust collected by the dust collector 100 can be mixed with the additive AD at an earlier stage. When taken out from the dust collector 100, the dust is raised to a state where it can be easily used by being more uniformly mixed with the additive AD.

  FIG. 2 is a block diagram showing a pulverized coal combustion facility in a coal-fired power generation system in which the dust collector 100 having the powder mixing processing means according to the first embodiment is provided. The pulverized coal combustion facility 1 includes a coal supply unit 12 that supplies coal, a pulverized coal generation unit 14 that converts the supplied coal into pulverized coal, a pulverized coal combustion unit 16 that burns pulverized coal, and combustion of pulverized coal. And a coal ash processing unit 17 for processing the generated coal ash. The dust collector 100 having the powder mixing processing means is arranged in the coal ash processing unit 17 and the additive AD is supplied into the dust collector 100, so that the mixture of the soot dust and the additive AD can be taken out.

  The coal supply unit 12 includes a coal bunker 121 that stores coal, and a coal feeder 122 that supplies the coal stored in the coal bunker 121. The coal bunker 121 stores coal to be supplied to the coal feeder 122. The coal feeder 122 continuously supplies the coal supplied from the coal bunker 121 to the coal pulverized coal machine 141. Moreover, this coal feeder 122 is provided with the apparatus which adjusts the supply_amount | feed_rate of coal, and, thereby, the amount of coal supplied to the coal pulverizer 141 is adjusted.

  The pulverized coal generation unit 14 includes a coal pulverized coal machine (mill) 141 that converts coal into pulverized coal capable of pulverized coal combustion, and an air supply unit 142 that supplies air to the coal pulverized coal machine 141. The coal pulverized coal machine 141 pulverizes the coal supplied from the coal feeder 122 through the coal supply pipe to a fine particle size to form pulverized coal, and is supplied from the pulverized coal and the air supply unit 142. Mix with fresh air. Thus, by mixing pulverized coal and air, the pulverized coal is preheated and dried to facilitate combustion. The formed pulverized coal is supplied with air to the pulverized coal combustion unit 16 by blowing air.

  The pulverized coal combustion unit 16 includes a furnace 161 that combusts the pulverized coal generated by the pulverized coal generation unit 14, a heater 162 (heat exchange unit) that heats the furnace 161, and an air supply that supplies air to the furnace 161. Machine 163. The furnace 161 is heated by the heater 162 (heat exchange unit), and combusts the pulverized coal supplied from the coal pulverized coal machine 141 via the pulverized coal pipe together with the air supplied from the air supply unit 163. Coal ash is generated by the combustion of the pulverized coal and is discharged to the coal ash treatment unit 17 together with the exhaust gas.

  The coal ash treatment unit 17 includes a denitration device 171, the dust collector 100 described above, and an ash silo 172. As the denitration device 171, a so-called dry ammonia catalytic reduction method for removing nitrogen oxides in exhaust gas is often used. That is, ammonia gas is injected as a reducing agent into a relatively high temperature (300 to 400 ° C.) exhaust gas, and nitrogen oxides in the exhaust gas are decomposed into harmless nitrogen and water vapor by the action of the denitration catalyst. The dust collector 100 collects soot dust (coal ash) in the exhaust gas as described above, and is supplied with the additive AD by the additive supply mechanism 103, so that the soot dust (coal ash) and the additive AD mixed more uniformly. The mixture can be taken out. The ash silo 172 stores a mixture of soot (coal ash) and the additive AD carried out from the dust collector 100. Further, the exhaust gas from which the dust (coal ash) has been removed is discharged to the outside air via the desulfurizer 18 and then the discharge part 19 such as a chimney.

  In the additive supply mechanism 103, dry air is used as the air of the blow-through rotary valve 103b for injecting or spraying the additive AD into the dust collector. However, in addition to dry air, a part of cleaner exhaust gas through the dust collector 100 may be introduced through a filter or the like. As a part of cleaner exhaust gas, exhaust gas at the front stage or the rear stage of the desulfurization apparatus 18 can be considered. The carry-out control mechanism 104 uses a rotary valve or the like to perform control for extracting the mixture of the dust and the additive AD accumulated in the dust collection hopper 102 to the outside.

  According to the above configuration, the exhaust gas is an exhaust gas that has been burned with pulverized coal, the soot is spherical fine particles (fly ash) of coal ash, and the additive AD is composed of one or more heavy metals contained in soot (coal ash). It contains substances that have the ability to insolubilize heavy metals when reacted. Thus, the fly ash and the additive AD that suppresses the elution of harmful trace elements in the fly ash are brought into contact with each other in the dust collector 100. This contributes to the promotion of environmentally friendly treatment with a large amount of coal ash (fly ash) with economical facilities.

  In addition, the additive supply mechanism 103 employs a blow-through rotary valve 103b that injects or disperses the additive AD into the dust collector 100, and uses dry air as a carrier for the additive AD or, if necessary, the dust collector 100. A part of the cleaner exhaust gas is introduced through a filter or the like. As a result, the additive AD is efficiently supplied into the dust collector 100 while minimizing environmental changes in the dust collector 100. The additive AD is supplied as fine powder so as to be blown into the dust collector 100, contacts and mixes with the collected dust, and contributes to the promotion of the subsequent reaction.

  Means adopted by the additive supply mechanism 103 to inject or spray the additive AD into the dust collector 100 is not limited to a blow-through rotary valve, but a mechanism that combines a rotary valve, a rotary valve, and an injection nozzle. A mechanism that combines a blower mechanism such as a rotary valve and a fan is conceivable (not shown). Although it is conceivable to supply the additive AD in a sprayed state, it is desirable not to change the environment in the dust collector 100 as much as possible, and the additive AD is preferably a dry powder.

  FIG. 3 is a schematic configuration diagram showing a dust collector having powder mixing processing means according to the second embodiment of the present invention. In this embodiment, the additive supply mechanism 203 is different from that in FIG. 1 of the first embodiment. Since the other configuration is the same, the same reference numerals as those in FIG.

  The additive supply mechanism 203 is provided with a supply port 203a for the additive AD so that the additive AD enters above the dust collection hopper 102, for example, into the dust collection mechanism 101 of the dust collector 100. Thereby, with the collection of the soot dust in the dust collection mechanism 101, the additive AD is also collected by the dust collection mechanism 101 by a predetermined amount. Therefore, the dust falling on the dust collection hopper 102 and the additive AD are mixed. The component of the additive AD is not particularly limited, but is preferably a powder (fine powder) as in the first embodiment. As the additive AD, a substance that suppresses the elution of harmful trace elements such as boron, fluorine, selenium, arsenic, and hexavalent chromium contained in the coal ash may be selected as the dust AD, for example, coal ash. The additive AD at this time is an elution preventing agent containing, as a main component, at least one selected from the group consisting of calcium compounds such as limestone, slaked stone, and quicklime. An elution inhibitor selected from the group consisting of calcium compounds such as limestone, slaked stone, and quicklime is readily available at a relatively low cost, and includes harmful trace elements such as boron, fluorine, selenium, and arsenic. Elution can be effectively suppressed.

  Also in the additive supply mechanism 203, a blow-through rotary valve 203b is provided to supply the additive AD as described above, for example, toward the inside of the dust collection mechanism 101. The blow-through rotary valve 203b sprays or sprays the additive AD that has moved to the supply port 203a. The additive AD that has reached the dust collecting mechanism 101 together with the exhaust gas is collected together with soot in the dust collecting mechanism 101. The dust falling on the dust collection hopper 102 and the additive AD are mixed.

  According to the above configuration, the dust collector 100 is provided with the additive supply mechanism 203 therein. Thereby, the dust in the dust collector 100 can be mixed with the additive AD immediately after collection. When taken out from the dust collector 100, the dust is raised to a state where it can be easily used by being more uniformly mixed with the additive AD.

  In the second embodiment, the same can be explained by replacing the additive supply mechanism 103 with 203 in the block diagram shown in FIG. 2 and replacing the blow-through rotary valve 103b with 203b. Similar actions and effects can be obtained.

  Also in the additive supply mechanism 203, in order to inject or disperse the additive AD into the dust collector 100, not only the blow-through rotary valve but also a rotary valve, a mechanism combining the rotary valve and the injection nozzle, A mechanism combined with a blowing mechanism such as a fan is conceivable (not shown). Although it is conceivable to supply the additive AD in a sprayed state, it is desirable not to change the environment in the dust collector 100 as much as possible, and the additive AD is preferably a dry powder.

  FIG. 4 is a schematic configuration diagram showing a dust collector having powder mixing processing means according to the third embodiment of the present invention. Compared with FIG. 1 of the first embodiment, this embodiment is different in a part in which a mixing mechanism 301 is further added to the bottom of the dust collecting hopper 102. Since the other configuration is the same, the same reference numerals as those in FIG.

  As the mixing mechanism 301, a mixer 302 with rotating blades can be considered. The shape of the rotary feather is not limited. Thereby, the mixture of the dust falling on the dust collection hopper 102 and the additive AD can be in a more uniform mixed state. Although not shown in the figure, the same effect can be obtained by adding the mixing mechanism 301 as described above to the configuration of FIG. 3 of the second embodiment.

  FIG. 5 is a schematic configuration diagram showing a dust collector having powder mixing processing means according to the fourth embodiment of the present invention. This embodiment is different from the first embodiment in FIG. 1 in that the mixing mechanism 401 is further added to the bottom of the dust collecting hopper 102. Since the other configuration is the same, the same reference numerals as those in FIG.

  The mixing mechanism 401 is provided with an air blow output unit 402 at the bottom of the dust collection hopper 102. The air blow output unit 402 instantaneously produces air blow from the bottom of the dust collecting hopper 102 via the compressor 403, the air receiver 404, and various control valve mechanisms 405. As a result, the mixture of the dust and the additive AD accumulated in the dust collection hopper 102 can be in a more uniform mixed state. The compressor 403 may be used in common for each air blow output unit 402. Although not shown, the same effect can be obtained by adding the mixing mechanism 401 as described above to the configuration of FIG. 3 of the second embodiment.

  FIG. 6 is a flowchart showing a powder mixing method according to the fifth embodiment of the present invention. In the process in which the exhaust gas that has undergone predetermined combustion transfers cleaner exhaust gas through the dust collector, in the first dust collection step S501, the dust contained in the exhaust gas is collected by the dust collector. A dust collector is the dust collector 100 of FIG. 1, for example, and there exists an example by which the dust medium (for example, coal ash) in waste gas is collected by the dust collection mechanism 101 as 1st dust collection process S501. After the processing of the first dust collection step S501, the process proceeds to the second dust collection step S502.

  In 2nd dust collection process S502, mixing process S5021 is accompanied in the front | former stage. In the second dust collection step S <b> 502, for example, the soot collected by the dust collection mechanism 101 of FIG. 1 is accumulated in the gravity direction in the sedimentation region of the dust collection hopper 102. At this time, an additive supply port 103 a is provided above the sedimentation region of the dust collection hopper 102, and the additive AD is supplied so as to come into contact with the dust falling on the dust collection hopper 102. With such an example, the dust collected by the dust collector can be mixed with the additive at an earlier stage. After the completion of the second dust collection step S502, the process proceeds to the unloading step S503. In the unloading step S503, for example, when the dust is taken out from the dust collection hopper 102 in FIG. 1, the dust is raised to a state that is easy to use by being more uniformly mixed with the additive AD.

  FIG. 7 is a flowchart showing a powder mixing method according to the sixth embodiment of the present invention. In the process in which the exhaust gas that has undergone predetermined combustion transfers cleaner exhaust gas through the dust collector, the first dust collection step S601 involves a mixing step S6011. In the first dust collection step S601, a predetermined amount of additive for the purpose of mixing is also collected along with the collection of the soot dust by the dust collection mechanism in the dust collector. For example, in FIG. 3, the additive AD is supplied from the supply port 203 a disposed near the inlet duct of the exhaust gas, and the dust collection mechanism 101 collects a predetermined amount of the additive AD along with the collection of the dust in the dust collection mechanism 101. There is an example. After the processing of the first dust collection step S601, the process proceeds to the second dust collection step S602.

  In the second dust collecting step S602, the dust collected with the additive by the dust collector is accumulated in the gravity direction by its own weight under the dust collector as a mixture of the dust and the additive. In the second dust collection step S602, for example, in FIG. 3, when falling to the dust collection hopper 102, the soot dust and the additive AD are more uniformly mixed. With such an example, the dust in the dust collector can be mixed with the additive immediately after collection. After the completion of the second dust collection step S602, the process proceeds to the unloading step S603. In the unloading step S603, for example, when the dust is taken out from the dust collection hopper 102 of FIG. 3, the dust is raised to a state where it can be easily used by being more uniformly mixed with the additive AD.

  As described above in each embodiment, according to the present invention, soot (coal ash) in a dust collector is collected earlier by being supplied with an additive (for example, calcareous raw material) in the dust collector. Can be mixed with additives in stages. Therefore, it becomes difficult for extra substances to intervene in the relationship between the dust and the additive, and when taken out from the dust collection hopper, the dust is raised to an easy-to-use state by being more uniformly mixed with the additive. As a result, a powder mixing process that can reduce the cost by reducing large-scale capital investment as much as possible, and can mix the dust that can be used effectively with the additive at an early stage and carry it out in a more usable state. A dust collector having a means and a powder mixing method using the same can be provided.

  In addition, the dust collector having the powder mixing means is not limited to the application to the coal-fired power generation system, but also applied to the installed dust collector and dust collector in other power generation systems and combustion systems such as refuse incineration. It is a possible technology.

It is a schematic block diagram which shows the dust collector which has the powder mixing process means which concerns on 1st Embodiment of this invention. It is a block diagram which shows the pulverized coal combustion facility in the coal thermal power generation system which provided the dust collector which has the powder mixing process means which concerns on 1st Embodiment of this invention. It is a schematic block diagram which shows the dust collector which has the powder mixing process means which concerns on 2nd Embodiment of this invention. It is a schematic block diagram which shows the dust collector which has the powder mixing process means which concerns on 3rd Embodiment of this invention. It is a schematic block diagram which shows the dust collector which has the powder mixing process means which concerns on 4th Embodiment of this invention. It is a flowchart which shows the powder mixing processing method which concerns on 5th Embodiment of this invention. It is a flowchart which shows the powder mixing processing method which concerns on 6th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Dust collector 101 Dust collection mechanism 102 Dust collection hopper 103, 203 Additive supply mechanism 103a, 203a Additive supply port 103b, 203b Blow-through type rotary valve 104 Unloading control mechanism AD additive 301, 401 Mixing mechanism 302 Mixer 402 Air blow output part 403 Compressor 404 Air receiver 405 Control valve mechanism 1 Pulverized coal combustion facility 12 Coal supply unit 121 Coal bunker 122 Coal feeder 14 Pulverized coal generation unit 141 Coal pulverized coal machine 142 Air supply unit 16 Pulverized coal combustion unit 161 Furnace 162 Heater 163 Air supply unit 17 Coal ash treatment unit 171 Denitration device 172 Ash silo 18 Desulfurization device 19 Discharge unit S501, S601 First dust collection step S502, S602 Second dust collection step S5021, S6011 Mixing step S503, S 03 unloading step

Claims (9)

A dust collector in a coal-fired power generation system,
A dust collection mechanism that has a chamber through which exhaust gas that has passed through the combustion of pulverized coal passes, collects dust contained in the exhaust gas, and transfers cleaner exhaust gas;
A sedimentation area provided below the dust collection mechanism, in which the dust collected by the dust collection mechanism is accumulated in the direction of gravity by its own weight;
An additive supply mechanism for supplying an additive for mixing with the dust,
An unloading control mechanism for extracting the mixture of the dust and the additive to the outside;
Equipped with a,
The dust has a spherical nanoparticle of coal ash, the additive viewed contains a substance capable of insolubilizing the heavy metal when reacted with one or more heavy metals contained in the dust,
The said additive supply mechanism is a dust collector which has a powder mixing process means provided so that the said coal ash may be mixed with the said additive in the stage after collection by the said dust collection mechanism .   The dust collector having a powder mixing processing unit according to claim 1, wherein the additive supply mechanism is a mechanism for injecting the additive.   The dust collector having a powder mixing processing unit according to claim 1, wherein the additive supply mechanism is a mechanism for spraying the additive.   The dust collector having the powder mixing processing means according to any one of claims 1 to 3, wherein the additive supply mechanism has a mechanism for collecting the additive by the dust collecting mechanism.   The dust collector having the powder mixing processing means according to any one of claims 1 to 4, wherein the additive supply mechanism includes a mechanism for introducing air.   The powder mixing processing means according to any one of claims 1 to 5, further comprising a mixing mechanism with a rotating blade that makes the mixture of the dust and the additive in a more uniform mixed state at the bottom of the settling region. Dust collector. In the process where the exhaust gas that has passed through the combustion of pulverized coal in the coal-fired power generation system passes through the dust collector and is transferred as clean exhaust gas,
A first dust collecting step in which soot dust having spherical fine particles of coal ash contained in the exhaust gas is collected by the dust collector;
A second dust collecting step in which the soot collected by the dust collector is accumulated in the direction of gravity below the dust collector,
Supplying an additive into the dust collector, and mixing the dust and the additive in the second dust collecting step; and
An unloading step for unloading the mixture of the dust and the additive;
With
The powder mixing method, wherein the additive includes a substance having an ability to insolubilize the heavy metal when reacted with one or more heavy metals contained in the dust.   The powder mixing method according to claim 7, wherein the mixing step uses air.   The powder mixing method according to claim 7 or 8, wherein the mixing step includes a step of collecting a predetermined amount of the additive by the dust collector in association with the first dust collecting step.

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