JP2019178857A - Sludge incineration facility and sludge incineration method - Google Patents

Abstract

To securely prevent clogging of a flue caused by adhesion and accumulation of incinerated ash that is generated when dry sludge is incinerated on the flue, and also securely prevent flowing failure caused by adhesion of incinerated ash on fluid sand surfaces and thus bonding and granulation of fluid sand particles.SOLUTION: A sludge incineration facility includes: an incinerator for incinerating sewage sludge; analysis means for performing a differential thermal analysis using incinerated ash generated when the sewage sludge is incinerated; and a control section for issuing either of a first instruction for starting or stopping supply of a medical agent to the sewage sludge for preventing adhesion and accumulation of harmful compounds on apparatuses and elements of the sludge incineration facility or a second instruction for controlling a temperature inside the fluid incinerator, on the basis of a result from the differential thermal analysis.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sludge incineration facility and a sludge incineration method.

  A water purification system represented by a sewage treatment plant includes a sewage purification process, a sludge treatment process, and a sludge incineration process. The sewage purification process has a process of mixing and aeration of sewage separated from garbage and raw sludge and activated sludge containing microorganisms, separating the activated sludge from the sewage, and finally sterilizing the sewage from which the activated sludge has been separated. . Further, the sludge treatment process includes a process of concentrating and dewatering sewage sludge including raw sludge generated in the sewage purification process and part of activated sludge (excess sludge), and may include a process of drying. The sewage sludge that has passed through the sludge treatment process is reduced in volume by being incinerated in the sludge incineration process.

  In the sludge incineration process described above, sewage sludge is incinerated, for example, in a fluidized incinerator. The fluidized incinerator is a facility that blows air into a fluid medium such as silica sand (hereinafter, fluidized sand) to form a fluidized bed in the furnace and heats and incinerate sewage sludge in the fluidized bed. When sewage sludge is incinerated in a fluidized incinerator, incinerated ash is discharged together with exhaust gas from the outlet of the fluidized incinerator. Incineration ash discharged with exhaust gas consists of a wide variety of components. The higher the content of phosphorus and phosphorus compounds empirically, the more the incineration ash adheres to and accumulates in the flue and equipment inside the incinerator outlet. It is known that the phenomenon of clogging and incineration ash adheres to the surface of fluidized sand, and the phenomenon that fluidized sand particles are bonded and granulated and cannot maintain a proper fluidized state (flow failure) is likely to occur. . These events include those caused by volatilization and condensation of phosphorus, and those caused by liquefaction of low melting point phosphorus compounds, but not all of these events have been clarified. These events hinder stable operation in sludge incineration facilities. Recently, advanced treatment of sewage is beginning to progress, and the concentration in sludge seems to be increasing, and countermeasures are urgently needed.

  As a method for preventing the blockage of the flue resulting from the incineration ash generated and deposited in the sludge incineration process, for example, adding a chemical such as polyferric sulfate to sewage sludge (Patent Document 1). reference). Moreover, adjusting the component of sludge is also proposed by adding the chemical | medical agent of the addition amount based on content and component ratio of the substance (element) contained in sewage sludge to a sewage sludge (patent document 2,). 3). Furthermore, for example, a method of adjusting the addition amount of a drug based on the color of incineration ash generated during incineration or the composition of a specific compound (oxide) contained in the incineration ash has been proposed (see Patent Document 4). .

Japanese Patent No. 3664592 Japanese Patent No. 4514529 Japanese Patent No. 5976152 Japanese Patent No. 5881260

  For example, in patent document 1, it is disclosed that the addition amount of an iron-type chemical | medical agent shall be 3-6% of the dry sludge conversion weight of sludge. However, in the case of Patent Document 1, the amount of iron-based chemical added to sludge does not consider the content of chemical substances and compounds contained in sludge, and the content of chemical substances and compounds contained in sludge It is not always constant. As a result, it is difficult to say that the amount of iron-based chemical added to the sludge is necessarily appropriate. Similarly, in the case of Patent Document 2 and Patent Document 3, the contents and component ratios of chemical substances and compounds contained in dehydrated sludge are referred to, but the contents and components of chemical substances and compounds contained in dehydrated sludge are referred to. The ratio is not necessarily constant. For example, when adding an iron-based chemical to be added to sludge, it is well known that the cost of the sludge incineration process is expensive, and the content of chemical substances and compounds contained in the sludge changes and the addition of iron-based chemicals When the amount becomes small, flue blockage or incineration ash adheres to the surface of the fluidized sand due to the deposition of incineration ash. Or, when the content of chemical substances and compounds contained in the sludge changes and the amount of iron-based chemicals added is large, the flue blockage or incineration ash flow caused by the deposition and deposition of incineration ash Although generation | occurrence | production etc. to the surface of sand can be prevented, the expense concerning a sludge incineration process will increase more than necessary by adding an iron-type chemical | medical agent.

  In addition, when determining the amount of iron-based chemicals to be added based on the color of the incinerated ash and the composition of the compounds contained in the incinerated ash, the composition of the compounds contained in the incinerated ash is complex, so the iron-based chemicals can be added appropriately. It is difficult to judge whether

  The present invention reliably prevents clogging of the flue caused by incineration ash generated when incinerated dry sludge adheres to and accumulates on the flue, and the incineration ash adheres to the surface of the fluidized sand. It is an object of the present invention to provide a sludge incineration facility and a sludge incineration method that can reliably prevent poor flow due to particles being bonded and granulated. In other words, the compounds contained in the sludge-derived incineration exhaust gas that adhere to and accumulate on the equipment and elements that make up the sludge incineration equipment are regarded as harmful compounds, and the harmful compounds adhere to and accumulate on the equipment and elements of the sludge incineration equipment. An object of the present invention is to provide a sludge incineration facility and a sludge incineration method capable of supplying an appropriate amount of a chemical agent that prevents the exhaust gas flow path from being blocked and caused by poor flow.

  In order to solve the problems described above, one aspect of the sludge incineration facility of the present invention performs a differential thermal analysis using an incinerator for incinerating sewage sludge and incineration ash generated when the sewage sludge is incinerated. A first instruction indicating the start or stop of supply to the sewage sludge of an analysis means and a chemical that prevents the deposition of harmful compounds on the equipment and elements of the sludge incineration facility based on the result of the differential thermal analysis, or And a control unit that issues any one of the second instructions for adjusting the temperature in the incinerator.

  One aspect of the sludge incineration facility of the present invention is an incinerator for incinerating sewage sludge, an analysis means for performing differential thermal analysis using incineration ash generated when the sewage sludge is incinerated, and the differential heat. Based on the result of the analysis, the first instruction to adjust the supply amount to the sewage sludge of the chemical that prevents the deposition of harmful compounds on the equipment and elements of the sludge incineration facility, or the temperature in the incinerator is adjusted And a control unit that performs any one of the second instructions.

  In addition, the control unit detects a decrease start temperature of the endothermic peak of the incinerated ash generated in a predetermined temperature range from the result of the differential thermal analysis, and compares the detected decrease start temperature with a preset target value. By doing so, either the first instruction or the second instruction is performed.

  In this case, heat exchange is performed between the combustion exhaust gas discharged from the incinerator for incinerating the sewage sludge and the combustion air sent to the incinerator for incinerating the sewage sludge, and the combustion air is preheated. And an air preheater that detects the descent start temperature based on a temperature inside the incinerator that incinerates the sewage sludge and a temperature of combustion exhaust gas discharged from the air preheater. It is preferable to set the temperature range.

  Moreover, it is preferable that the said control part sets the lower limit of the said temperature range based on the temperature of the incinerator which incinerates the said sewage sludge, and the temperature of the combustion exhaust gas discharged | emitted from the said air preheater.

  In addition to the comparison between the newly calculated descent start temperature and the target value, the control unit includes the descent start temperature calculated during the previous comparison and the newly calculated descent start temperature. A comparison is performed.

  Further, the incinerator for incinerating the sewage sludge is a fluidized incinerator for forming a fluidized bed by a fluidized medium by blown air and incinerating the sewage sludge to be charged in the fluidized bed. To do.

  In addition, the chemical is supplied to the sewage sludge from when the sewage sludge is generated to when it is put into the incinerator for incinerating the sewage sludge, or to the incinerator for incinerating the sewage sludge. It is preferable to supply directly.

  In this case, the chemical is at least before concentrating the sewage sludge, before dehydrating the sewage sludge, before drying the sewage sludge, or before entering the incinerator for incinerating the sewage sludge. It is preferable to supply the sewage sludge at any one timing.

  Also, one aspect of the sludge incineration method of the present invention is a step of incinerating sewage sludge using an incinerator for incinerating sewage sludge, and a step of performing differential thermal analysis using incineration ash obtained by incineration of the sewage sludge. And, based on the result of the differential thermal analysis, a first instruction indicating the start or stop of supply of the chemical to the sewage sludge with a chemical that prevents the deposition of harmful compounds on the equipment and elements of the sludge incineration facility, or the sewage And a step of performing any one of the second instructions for adjusting the temperature in the incinerator for incinerating sludge.

  Also, one aspect of the sludge incineration method of the present invention is a step of incinerating sewage sludge using an incinerator for incinerating sewage sludge, and a step of performing differential thermal analysis using incineration ash obtained by incineration of the sewage sludge. And, based on the results of the differential thermal analysis, a first instruction for adjusting the supply amount of a chemical that prevents the deposition and deposition of harmful compounds on the equipment and elements of the sludge incineration facility, or in an incinerator that incinerates the sewage sludge A step of performing any one of the second instructions for adjusting the temperature of the liquid crystal.

  Here, the step of performing any one of the first instruction and the second instruction includes a step of detecting a decrease start temperature of the endothermic peak of the incinerated ash generated in a predetermined temperature range from the result of the differential thermal analysis. And a step of comparing the detected drop start temperature with a preset target value.

  In this case, the comparing step uses the temperature of the incinerator for incinerating the sewage sludge and the temperature of the combustion exhaust gas after preheating the combustion air by heat exchange in the air preheater. It is preferable to include a step of setting a temperature range for detecting the temperature at which the endothermic peak starts to fall.

  Here, the step of setting the temperature range sets a lower limit value of the temperature range based on the temperature inside the incinerator for incinerating the sewage sludge and the temperature of the combustion exhaust gas discharged from the air preheater. It is characterized by that.

  The comparing step includes, in addition to the comparison between the newly calculated drop start temperature and the target value, the drop start temperature calculated at the previous comparison, and the newly calculated drop start temperature. It is preferable to make a comparison.

  Moreover, the step of incinerating the sewage sludge is a step of forming a fluidized bed of fluidized sand by air blown into a fluidized incinerator and incinerating the sewage sludge to be charged into the fluidized incinerator in the fluidized bed. It is characterized by being.

  In addition, the method further includes the step of supplying the chemical until the sewage sludge is put into an incinerator for incinerating the sewage sludge or to the incinerator for incinerating the sewage sludge. In this case, the step of supplying the chemical is performed before the sewage sludge is concentrated, before the sewage sludge is dehydrated, before the sewage sludge is dried, or by incineration of incinerating the sewage sludge. It is preferable to implement at least one timing before charging into the furnace.

  According to the present invention, the blockage of the flue caused by the incineration ash generated when the sewage sludge is incinerated adheres to and accumulates on the flue can be reliably prevented. Further, according to the present invention, it is possible to prevent the increase in the particle size of the fluid sand, that is, adhesion and accumulation on the surface of the fluid sand, the substance contained in the incinerated ash adheres to the surface of the fluid sand, and the fluid sand particles are bonded to each other. It is possible to prevent flow failure caused by granulation. At the same time, incineration ash generated by incineration of sludge can be prevented from adhering to and accumulating on the flue. Further, according to the present invention, the compounds contained in the sludge-derived incineration exhaust gas that adhere to and deposit on the equipment and elements constituting the sludge incineration equipment are regarded as harmful compounds, and the harmful compounds are the equipment and elements of the sludge incineration equipment. It is possible to provide a sludge incineration facility and a sludge incineration method that can supply an appropriate amount of a chemical that prevents clogging of an exhaust gas flow path and poor flow caused by adhering to and depositing on a gas.

It is a schematic diagram which shows an example of a water purification system. It is a schematic diagram which shows an example of a sludge treatment equipment and a sludge incineration equipment. It is a schematic diagram which shows the outline | summary of the apparatus used by differential thermal analysis. It is a graph which shows the relationship between temperature and a heat flow. It is a flowchart which shows an example of a process in the case of performing the addition of a chemical | medical agent, the stop of addition, or adjustment of the addition amount of the chemical | medical agent added by logic control using the result of the differential thermal analysis of ash. (A) It is a graph which shows the relationship between the temperature before adding a chemical | medical agent, and a heat flow, (b) It is a graph which shows the relationship between the temperature after adding a chemical | medical agent, and a heat flow. It is a flowchart which shows an example of the process in the case of performing temperature adjustment inside an incinerator by logic control using the result of the differential thermal analysis of ash.

  Hereinafter, a first embodiment will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a diagram schematically illustrating an example of a water purification system 10. As shown in FIG. 1, the water purification system 10 is a system that purifies sewage such as domestic wastewater. The water purification system 10 includes a sewage purification facility 11, a sludge treatment facility 12, and a sludge incineration facility 13. The sewage purification equipment 11 is equipment for purifying sewage using, for example, an activated sludge method. Specifically, the sewage purification facility 11 includes a sand basin 21, a first sedimentation basin (first sedimentation basin) 22, a reaction tank (aeration tank) 23, and a final sedimentation basin (second sedimentation basin) 24. The sand basin 21 removes sediment and relatively large waste that flows in along with the sewage. The first settling basin 22 allows the sewage discharged from the settling basin 21 to flow for 2 to 3 hours, for example, to precipitate dirt contained in the sewage. The dirt first settled in the settling basin 22 is recovered as raw sludge 25a. The reaction tank 23 first mixes the sewage from the sedimentation basin 22 and activated sludge, aerates and stirs the inside of the reaction tank 23, and decomposes dirt (organic matter) contained in the sewage by the action of microorganisms contained in the activated sludge. To do.

  The final sedimentation basin 24 allows the sewage sent from the reaction tank 23 to flow for 3 to 4 hours, for example, to precipitate activated sludge contained in the sewage. A part of the activated sludge precipitated in the last settling basin 24 is returned to the reaction tank 23, and the remaining activated sludge is recovered as excess sludge 25b. The sewage from which the activated sludge has been separated by the last settling basin 24 is sterilized with chlorine in a chlorine contact tank (not shown) and then discharged into the sea or river as treated water.

  The sludge treatment facility 12 is a facility for reducing the amount of sewage sludge 25 generated in the sewage purification facility 11 by concentration, dehydration, or further drying. The sewage sludge 25 is an example of an object to be treated. The sewage sludge 25 includes raw sludge 25a removed from the first settling basin 22 and excess sludge 25b removed from the last settling basin 24. The sludge treatment facility 12 includes a concentration device 31, a dehydrator 32, and a dryer 33.

  The concentration device 31 separates the sewage sludge 25 into supernatant water and sludge components, that is, concentrates the solid content of the sewage sludge 25. The dehydrator 32 dehydrates the concentrated sewage sludge 25 to a moisture content of about 75 to 80%, for example. The dryer 33 dries the sewage sludge 25 dehydrated by the dehydrator 32 to, for example, a moisture content of about 20 to 30%. The sewage sludge 25 that has passed through the sludge treatment process is incinerated by the sludge incineration facility 13. The incineration ash generated when the sewage sludge 25 is incinerated by the sludge incineration facility 13 is disposed of in landfills or reused as resources. In FIG. 1, the sludge treatment facility 12 includes the concentration device 31, the dehydrator 32, and the dryer 33, but at least one of the concentration device 31, the dehydrator 32, and the dryer 33 is omitted or necessary. It is good also as sludge processing equipment which added other processes and equipments, such as reforming according to.

  FIG. 2 is a diagram schematically showing one configuration of the sludge treatment facility 12 and the sludge incineration facility 13. In addition, the arrow shown with the continuous line in FIG. 2 shows the discharge path of incineration exhaust gas and incineration ash other than supply paths, such as the sewage sludge 25 and combustion air, The arrow shown with the broken line in FIG. An arrow indicated by a two-dot chain line in FIG. 2 indicates a signal in the medicine supply path for preventing adhesion and deposition on an element such as a fluid bed.

  The sludge incineration facility 13 includes a fluidized incinerator (fluidized bed incinerator) 37, an air preheater (heat exchanger) 38, a dust collector 39, a flue gas treatment device 40, and a control device 43. As is well known, the fluidized incinerator 37 heats the fluidized sand fluidized by the combustion air blown into the furnace with a temperature rising burner, and the sewage sludge 25 charged into the furnace with the fluidized sand heated at a high temperature. It is equipment to heat and incinerate. The fluidized incinerator 37 includes a bubble fluidized incinerator, a circulating fluidized incinerator, a supercharged fluidized incinerator, and the like, and any fluidized incinerator may be used. In addition, a fluidized incinerator is used as an example of an incinerator.For example, the measured value of the recovered amount of incinerated ash generated when incinerated sewage sludge is measured, and the theoretical value of the recovered incinerated ash is calculated. If it can be obtained, for example, a staircase stoker furnace (ash can be collected from the ash hopper at the end of the stoker or fly ash to the flue), a vertical multi-stage incinerator (fly ash from each stage can be collected), etc. Other incinerators may be used as long as differential heat of ash generated by combustion in the furnace can be measured. Although illustration is omitted, the fluidized incinerator 37 includes a temperature rising burner that heats the inside of the furnace at a high temperature when the equipment is started, It has an auxiliary fuel device for supplying auxiliary fuel, and an air diffuser for sending combustion air into the furnace. Even in other types of incinerators, the moisture of the sludge that burns at high temperatures and the auxiliary fuel that adjusts the temperature and the air that contains oxygen are supplied in the same way, although the parts are different. Note that reference numeral 45 in FIG. 2 denotes a discharge path for sending the combustion exhaust gas discharged from the fluidized incinerator 37 to the air preheater 38.

  Although illustration is abbreviate | omitted, the fluid incinerator 37 has a discharge port in the lower part. For example, the sewage sludge 25 thrown into the fluidized incinerator 37 contains an incombustible material. Incombustibles in the sewage sludge remain in the lower part of the fluidized incinerator 37 without being incinerated. Therefore, by discharging the fluid sand from the discharge port, the incombustible material contained in the fluid sand is also recovered. The discharged fluid sand is sent again to the fluidized incinerator after the incombustible material is removed.

  The air preheater 38 performs heat exchange between the combustion exhaust gas discharged from the fluidized incinerator 37 and the combustion air sent from the blower 46 toward the air diffuser included in the fluidized incinerator 37. By the heat exchange by the air preheater 38, the combustion air sent toward the diffuser is preheated to 600 to 650 ° C., for example. For example, the temperature of the combustion exhaust gas discharged from the fluid incinerator 37 is 800 to 900 ° C., and the temperature of the combustion exhaust gas sent out from the air preheater 38 is lowered to 500 to 700 ° C. by heat exchange. Here, reference numeral 47 in FIG. 2 denotes a discharge path (flue) for discharging the combustion exhaust gas heat-exchanged by the air preheater 38 to the dust collector 39. Further, reference numeral 48 in FIG. 2 is a supply path for supplying the air sent from the blower 46 to the air preheater 38, and reference numeral 49 in FIG. 2 is a preheated combustion air that is supplied to the air diffuser of the fluidized incinerator 37. It is a supply channel.

  The dust collector 39 is a device that separates and collects incineration ash contained in the combustion exhaust gas discharged from the air preheater 38. An example of the dust collector 39 is a dust collector using a ceramic filter. The incinerated ash separated and collected by the dust collector 39 is accumulated in the ash hopper 51. In FIG. 2, reference numeral 52 is an exhaust path for sending the combustion exhaust gas from which the incineration ash has been removed by the dust collector 39 to the flue gas treatment apparatus 40, and reference numeral 53 indicates the incineration ash separated and collected by the dust collector 39. Is a discharge path for discharging the ash to the ash hopper 51.

  The smoke treatment apparatus 40 removes compounds that are harmful to the corrosion of the apparatus such as sulfur oxide and hydrogen chloride contained in the combustion exhaust gas.

  The ash hopper 51 accumulates the incinerated ash collected by the dust collector 39 and discharges it to a loading platform such as a truck.

  The control device 43 is composed of, for example, a PLC (programmable logic controller). The control device 43 may be used as a control device used to control each part of the sludge incineration facility 13 or may be a dedicated control device for carrying out the present invention. The control device 43 controls the start and stop of the addition of chemicals and the adjustment of the amount of added chemicals to prevent the deposition and deposition of harmful compounds on the equipment and elements of the facility to the sewage sludge 25 by the supply device 54 described later.

  The control device 43 receives a signal indicating a measurement result by a thermogravimetric / differential thermal analyzer (TG-DTA) 56 described later. Therefore, the control device 43 uses the signal to determine whether or not to add a drug to the sewage sludge and to determine whether or not to adjust the added amount of the added drug.

  The supply device 54 is a device that supplies the sewage sludge 25 with a chemical that prevents the deposition and deposition of harmful compounds on equipment and elements of the facility. In general, incineration ash generated when incineration of sewage sludge in a fluidized incinerator consists of a wide variety of components, and the higher the content of phosphorus and phosphorus compounds empirically, the more incinerated ash is discharged from the incinerator. Events that adhere to, accumulate, and block in the flue and equipment after the exit, or events that cause the incineration ash to adhere to the surface of the fluidized sand, and the fluidized sand particles combine and granulate to maintain the proper fluidity (flow) It is known that defects) are likely to occur. The mechanism may be due to the volatilization or condensation of phosphorus, or due to the liquefaction of a low melting point phosphorus compound, but not all of the mechanism has been clarified.

  Therefore, by adding the chemical | medical agent containing the basic compound containing any one of iron (Fe), calcium (Ca), aluminum (Al), magnesium (Mg) with the supply apparatus 54 to the sewage sludge 25, Prevent the occurrence of the above events. In addition, as a compound containing Fe, a polyferric sulfate etc. are mentioned. In addition, examples of the compound containing Ca include calcium carbonate, slaked lime, and quicklime. Moreover, polyaluminum chloride etc. are mentioned as a compound containing Al. Moreover, magnesium oxide etc. are mentioned as a compound containing Mg.

  The timing at which the chemical is added to the sewage sludge 25 is before the sewage sludge 25 is concentrated, before the concentrated sewage sludge 25 is dehydrated, before the dehydrated sewage sludge 25 is dried, or It is preferable to directly input the dried sewage sludge 25 into the fluidized incinerator 37 or at any one timing before the fluidized incinerator 37, or supply to any part of the sewage purification process, It does not deny the supply to the return water returned to the sewage purification process from the sludge treatment process or sludge incineration process.

  The thermogravimetric / differential thermal analyzer 56 is a device that acquires a part of the incinerated ash collected by the dust collector 39 and performs a differential thermal analysis using the acquired incinerated ash. The thermogravimetric analysis part is not essential. As is well known, differential thermal analysis is a method of measuring the temperature difference between a sample and a reference material as a function of temperature (or time) when the temperature between the sample and the reference material is changed. For example, when the temperature of the sample is changed, the sample undergoes reactions such as melting, glass transition, crystallization, decomposition, oxidation, and curing. During these reactions, thermal changes occur in the sample. Therefore, the thermogravimetric / differential thermal analyzer 56 used in the present embodiment measures the melting temperature of the sample using the incinerated ash collected by the dust collector 39 as a sample. Examples of the reference material used for the differential thermal analysis include a material that does not change thermally in the measurement temperature range, such as α-alumina.

  As shown in FIG. 3, in the differential thermal analysis, the sample 60 and the reference material 61 are installed at symmetrical positions inside the heater (heating furnace) 62, and the sample 60 and the reference material 61 are heated at a constant speed by the heater 62. To do. At this time, the temperature difference ΔT between the sample 60 and the reference material 61 is detected by the differential thermocouple 63 installed on the surface of the sample 60 and the reference material 61. In the present embodiment, for example, a change in the amount of heat (heat flow) is calculated based on the temperature difference obtained by the differential thermal analysis. The thermogravimetric / differential thermal analysis device 56 transmits data indicating the change in the heat flow when the temperature is changed to the control device 43. The differential thermal analysis of the incinerated ash by the thermogravimetric / differential thermal analyzer 56 is performed at a predetermined interval, for example, 12 hours, 1 day, 1 week, or the like.

  Returning to FIG. 2, the fluidized incinerator 37 described above is provided with a temperature sensor 57 that measures the internal temperature of the fluidized incinerator. The temperature sensor 57 sequentially transmits a signal indicating the measured temperature inside the incinerator to the control device 43.

  In addition, a temperature sensor 58 that measures the temperature in the vicinity of the air preheater 38 outlet is provided near the outlet of the air preheater 38. The temperature sensor 58 sequentially transmits a signal indicating the measured temperature in the vicinity of the outlet of the air preheater 38 to the control device 43.

  The control apparatus 43 mentioned above performs control, such as the start and stop of chemical | medical agent addition to the sewage sludge 25, adjustment of chemical | medical agent addition amount. In controlling the start and stop of the chemical addition to the sewage sludge 25 and the adjustment of the chemical addition amount, the control device calculates a relational expression indicating the relationship between the temperature and the heat flow from the data indicating the change in the heat flow based on the temperature change. Then, a process for obtaining a drop start temperature at which the endothermic peak of the sample starts is performed from the relational expressions calculated sequentially. This processing will be described below with reference to a graph as shown in FIG. 4 in which the calculation processing for obtaining the drop start temperature at which the endothermic peak of the sample starts from the graph.

  The process for obtaining the drop start temperature at which the endothermic peak of the sample starts is executed in the following order. FIG. 4 shows an example of a graph showing the relationship between temperature and heat flow. In FIG. 4, the horizontal axis represents temperature (° C.) and the vertical axis represents heat flow (DTA (μV) × 10).

  The control device 43 calculates a first set value T1 for limiting the temperature range in which the endothermic peak of the sample is included in the graph indicating the relationship between the temperature and the heat flow. In the present embodiment, the first set value T1 is used as the lower limit value of the temperature range. The meaning of setting the first set value T1 is that an endothermic peak unrelated to the endothermic peak of condensation (phase change) of a compound that may be a harmful compound in the sludge incineration facility 13 exists below the first set value T1. It means the operation of deleting it from the calculation. For example, this is to exclude an endothermic peak such as a phase change of silicon dioxide from alpha quartz to beta quartz.

  Here, as an example, the first set value T1 is an average value of the maximum temperature inside the fluidized incinerator 37 (hereinafter referred to as the maximum temperature of the fluidized incinerator) and the temperature near the outlet of the air preheater 38. Is mentioned. Hereinafter, the case where the average maximum temperature of a fluidized incinerator is used as the maximum temperature of the fluidized incinerator 37 will be described. As the maximum temperature of the fluidized incinerator 37, the maximum temperature (design value) of the fluidized incinerator 37 at the design stage of the fluidized incinerator 37 can be used. Further, the temperature inside the fluidized incinerator 37 is measured by the temperature sensor 57 every predetermined time, and the average value or the intermediate value of the measured temperature inside the fluidized incinerator 37 is the maximum temperature inside the fluidized incinerator 37. It can also be used instead of the average value of the temperature near the outlet of the air preheater 38 or an intermediate value.

  The control device 43 has a tangential slope (in other words, a slope) of a portion where the endothermic peak that appears at a temperature closest to the first set value T1 among the endothermic peaks included in the temperature range that is equal to or higher than the first set value T1. Find θ. The control device 43 sets the temperature at which the obtained gradient θ is obtained as the first set value T21 when the obtained gradient θ is greater than the preset gradient θth. The gradient θth is a value obtained by past history, simulation, or the like. Further, the gradient θth may be fixed or variable.

  The control device 43 determines whether or not the peak difference P, which is the difference between the heat flow value at the first set value T21 and the heat flow value at the bottom of the endothermic peak, is greater than or equal to the threshold value Pth. When the peak difference P is equal to or greater than the threshold value Pth, the control device 43 sets the first set value T21 as the drop start temperature T. The threshold value Pth is a value obtained by past history, simulation, or the like. The threshold value Pth may be fixed or variable.

  When the obtained gradient θ is less than the preset gradient θth, or when the peak difference P is less than the threshold value Pth, the control device 43 is included in the temperature range that is equal to or greater than the first set value T1. Among the endothermic peaks, the above-described processing (processing for obtaining the first set value T2n and processing for determining whether or not the peak difference P of the endothermic peaks is equal to or greater than the threshold value Pth) in order from the endothermic peak with the lower temperature. Repeat until the drop start temperature is determined. In addition, when the drop start temperature is not obtained, the control device 43 sets no data.

Hereinafter, based on the result of the differential thermal analysis of the incineration ash, an example of the flow of processing in the case where the start and stop of the addition of the medicine and the adjustment of the addition amount of the medicine are performed by logical control will be described with reference to the flowchart of FIG. explain. In FIG. 5, for the added amount of adjustment is used symbol _A 1 to A ₄ and symbols _B 1 ~B _4. Note that the control method may be logical control shown as an example, for example, PID control, FUZZY inference, etc., for example, a drop start temperature when there is a peak difference that is a heat flow value difference of an endothermic peak larger than the threshold value Pth, etc. It may be based on linear control (for example, feedback control). Also, a plurality of control methods can be used in combination. Hereinafter, the supply amount of the chemical supplied to the sewage sludge by the supply device 54 is referred to as a chemical addition amount, and the adjustment amount of the chemical supplied to the sewage sludge is referred to as an addition adjustment amount. Hereinafter, the drop start temperature T is referred to as a comparative value.

  Step S101 is processing for performing differential thermal analysis. The differential thermal analysis is executed by acquiring the incinerated ash discharged from the dust collector 39 to the ash hopper 51 and installing the acquired incinerated ash in the thermogravimetric / differential thermal analyzer 56. Here, the installation of the incinerated ash in the thermogravimetric / differential thermal analyzer 56 may be performed automatically or by an operator. The result of the differential thermal analysis is transmitted to the control device 43.

Step S102 is a process of calculating the drop start temperature T from the first set value T2n. The control device 43 obtains the drop start temperature T from the first set value T2n using the result of the differential thermal analysis. In the flowchart of FIG. 5, since is then compared with a drop starting temperature TA of the normal ash does not occur in condensation of toxic compounds, the following comparison value drop starting temperature T from the first set value T 2 n T _m (M = 1, 2, 3,...)

Step S103 is a process of determining whether or not the comparison value T _m is calculated. When the comparison value _Tm is calculated in step S102, the control device 43 sets the determination result in step S103 to Yes. In this case, the process after step S104 is performed. On the other hand, when the comparison value _Tm is not calculated, the control device 43 sets the determination result in step S103 to No. In this case, the process of the flowchart shown in FIG. In addition, when the result of the determination process in step S103 is No, processes such as changing the addition amount of the chemical liquid and starting and stopping the chemical liquid are not executed.

  When it determines with Yes by the process of step S103, the control apparatus 43 performs the several process shown below simultaneously. Hereinafter, the processing from step S104 to step S106 is the first arithmetic processing, the processing from step S107 to step S109 is the second arithmetic processing, the processing from step S110 and step S114 is the third arithmetic processing, and the processing from step S115 to step S118. This is referred to as a fourth calculation process. Moreover, the control apparatus 43 performs the 5th calculation process shown to step S121 and step S122 other than the 1st-4th calculation process mentioned above.

<First calculation process>
Step S104, the comparison value T _m calculated this time is the process of determining whether to exceed the target value T _0. If the comparison value _{T m} calculated this time exceeds the target value _{T 0,} the control unit 43, a Yes determination result in step S104. In this case, the process proceeds to step S105. On the other hand, when the comparison value _{T m} calculated this time is equal to or less than the target value _{T 0,} the control device 43, and No judgment result in step S104.

Step S105 is a process of determining whether or not the currently calculated comparison value _Tm is equal to or greater than the previously calculated comparison value _Tm−1 and whether the previous addition adjustment amount is a positive value. The control device 43 reads the previously calculated comparison value T _m−1 and the previous addition adjustment amount from the storage device. In comparison value T _m calculated this time is the last calculated comparison value T _m-1 or more, and if the added amount of adjustment and the previous positive value, the control unit 43, a Yes determination result in step S105. In this case, the process proceeds to step S106. On the other hand, in the comparison value T _m calculated this time is the last calculated comparison value T _m-1 or more, and if not the adding adjustment amount and the previous positive value, the control unit 43, No the result of the determination in step S105 And

Step S106 is a process for determining the current addition adjustment amount. Controller 43 reads out the previous added adjustment amount or in step S105, the other comparison values T _m and the target value T ₀ calculated and the like based on descent temperature variation in placing the drug, compared determining the added amount of adjustment of the current so as to approach the value T to the target value T _0. For example, if the comparison value T _m, which is calculated after differential thermal analysis after the addition adjustment amount + A ₁ of the last time exceeds the target value T ₀ is, it can be determined that there is often added amount of the agent, like this In this case, the additive adjustment amount of the drug is, for example, −B ₁ (B ₁ <A ₁ ).

That is, in the first calculation process, the calculated comparison value T _m exceeds the target value T ₀ , the currently calculated comparison value T _m is equal to or more than the previously calculated comparison value T _m−1 , and the previous drug addition adjustment when the amount of positive, control device 43, so as to decrease the amount of drug determines the addition amount of adjustment of the drug, to converge the comparison value T _m to a target value T _0.

<Second arithmetic processing>
Step S107, the comparison value T _m calculated this time is the process of determining whether it is less than the target value T _0. If the comparison value _{T m} calculated this time is less than the target value _{T 0,} the control unit 43, a Yes determination result in step S107. In this case, the process proceeds to step S108. On the other hand, when the comparison value _{T m} calculated this time becomes the target value _{T 0} or more, the control device 43, and No the decision result in the step S107.

Step S108 is a process of determining whether or not the currently calculated comparison value _Tm is equal to or less than the previously calculated comparison value _Tm−1 and whether the previous addition adjustment amount is a negative value. The control device 43 reads the previously calculated comparison value T _m−1 and the previous addition adjustment amount from the storage device. Comparison value T _m calculated this time is the comparison value T _m-1 below the previously calculated, and if the added amount of adjustment of the previous negative value, the control unit 43, a Yes determination result in step S107. In this case, the process proceeds to step S109. On the other hand, in the comparison value T _m-1 below a comparison value T _m calculated this time is previously calculated, and if the addition amount of adjustment of the last is not a negative value, the control device 43, and No the determination result of step S108 To do.

Step S109 is processing for determining the current addition adjustment amount. Controller 43 reads out the previous added adjustment amount or in step S108, the other comparison values T _m and the target value T ₀ is calculated, based on such a drop starting temperature of the amount of change by pouring the drug, a comparison value T _m as close to the target value T _0, determines the added amount of adjustment time. For example, the comparison value T _m calculated after the previous addition adjustment amount −A ₂ is less than the target value T ₀ , and the currently calculated comparison value T _m is equal to or less than the previously calculated comparison value T _m−1. Therefore, it can be determined that the addition amount of the drug is small. In such a case, the adjustment amount of the drug addition is, for example, + B ₂ (B ₂ <A ₂ ).

That is, in the second calculation process, the comparison value T _m is less than the target value T ₀ , the currently calculated comparison value T _m is equal to or less than the previously calculated comparison value T _m−1 , and the previous drug addition adjustment amount is negative. comprising a case, the control device 43, so as to increase the amount of drug determines the addition amount of adjustment of the drug, to converge the comparison value T _m to a target value T _0.

<Third arithmetic processing>
Step S110, the comparison value T _m calculated this time is the process of determining whether it is equal to the target value T _0. If the comparison value _{T m} calculated this time is the same as the target value _{T 0,} the control unit 43, a Yes determination result in step S110. In this case, the process proceeds to step S111. On the other hand, when the comparison value T _m calculated this time is not the same as the target value T _0, the control device 43, and No the decision result in the step S110.

Step S111 is a process of determining whether or not the currently calculated comparison value _Tm exceeds the previously calculated comparison value _Tm−1 and whether the previous addition adjustment amount is a positive value. The control device 43 reads the previously calculated comparison value T _m−1 and the previous addition adjustment amount from the storage device. Exceeds a comparison value T _m-1 comparison value T _m calculated this time is previously calculated, and if the added amount of adjustment of the last a positive value, the control unit 43, a Yes determination result in step S111 . In this case, the process proceeds to step S112. On the other hand, less than the comparison value T _m-1 comparison value T _m calculated this time is previously calculated, and if the addition amount of adjustment of the last is not a positive value, the control device 43, and No the determination result of step S111 To do. In this case, the process proceeds to step S113.

Step S112 is a process of determining the current addition adjustment amount. Controller 43 reads out the previous added adjustment amount or in step S111, the other comparison values T _m and the target value T ₀ is calculated, based on such a drop starting temperature of the amount of change by pouring the drug, so as to approach the comparison value T _m to a target value T ₀ to determine the added amount of adjustment time. For example, when the comparison value T _m calculated after the previous addition adjustment amount + A ₃ is the same as the target value T ₀ and the currently calculated comparison value T _m exceeds the previously calculated comparison value T _m−1 Therefore, it can be determined that the addition amount of the drug is large. In such a case, the addition adjustment amount of the drug is, for example, −B ₃ (B ₃ <A ₃ ).

Step S113 is less than the comparison value T _m-1 comparison value T _m calculated this time is previously calculated, is and the process of determining whether it has the added amount of adjustment of the previous negative value. The control device 43 reads the previously calculated comparison value T _m−1 and the previous addition adjustment amount from the storage device. In comparison value less than T _m-1 comparison value T _m calculated this time is previously calculated, and if the added amount of adjustment of the previous negative value, the control unit 43, a Yes determination result in step S113. In this case, the process proceeds to step S114. On the other hand, when the comparison value T _m calculated this time is the same as the comparison value T _m-1 previously calculated, and if not the adding adjustment amount of the previous negative value, the control device 43, step S113 The determination result is No.

Step S114 is processing for determining the current addition adjustment amount. Control device 43, the last added adjustment amount and the read out in step S113, the other comparison values T _m and the target value T ₀ is calculated, based on such variation of comparison value by turning on the drug, this The addition adjustment amount of is determined. For example, the comparison value T _m calculated after setting the previous addition adjustment amount −A ₄ is the same as the target value T ₀ , and the comparison value T _m calculated this time is less than the comparison value T _m−1 calculated last time. In this case, it can be determined that the addition amount of the medicine is small. In such a case, the addition adjustment amount of the medicine is, for example, + B ₄ (B ₄ <A ₄ ).

That is, in the third calculation process, the comparison value T _m is the same as the target value T ₀ , the currently calculated comparison value T _m exceeds the previously calculated comparison value T _m−1 , and the previous addition adjustment amount is positive. comprising a case, the control device 43, so as to decrease the amount of drug determines the addition amount of adjustment of the drug, to converge the comparison value T _m to a target value T _0. Further, the same as the comparison value T _m is the target value T _0, when the comparison value T _m calculated this time is the last added amount of adjustment and less than comparison value T _m-1 previously calculated is negative, the control device No. 43 determines the addition adjustment amount of the drug so as to increase the addition amount of the drug, and converges the comparison value T _m to the target value T ₀ .

<Fourth arithmetic processing>
Step S115 is a comparison value T _m calculated this time is determined whether or not it is less than the threshold L _0. Here, the threshold value L ₀ is a lower limit side threshold value set for the target value T ₀ . When comparison value _{T m} calculated this time is less than the threshold _{L 0,} the control unit 43, a Yes determination result in step S115. In this case, the process proceeds to step S116. On the other hand, when the comparison value _{T m} calculated this time is not less than the threshold value _{L 0,} the control device 43, and No the decision result in the step S115. In this case, the process proceeds to step S117.

Step S116 is processing for determining the current addition adjustment amount. The control device 43 brings the comparison value T _m closer to the target value T ₀ based on the calculated comparison value T _m and the target value T ₀ as well as the amount of change in the comparison value T due to the injection of the medicine. The amount of addition adjustment this time is determined. For example, when the comparison value T _m calculated this time is less than the threshold L _0, the addition adjustment amount of the drug is, for example, + B _5.

Step S117 is a comparison value T _m calculated this time is determined whether or not the threshold value H ₀ above. Here, the threshold value H ₀ is an upper limit side threshold value set for the target value T ₀ . If the comparison value _{T m} calculated this time becomes the threshold value _{H 0} above, the control device 43, a Yes determination result in step S117. In this case, the process proceeds to step S118. On the other hand, when the comparison value _{T m} calculated this time is less than the threshold value _{H 0,} the control device 43, and No the decision result in the step S117.

Step S118 is processing for determining the current addition adjustment amount. The control device 43 brings the comparison value T _m closer to the target value T ₀ based on the calculated comparison value T _m and the target value T ₀ as well as the amount of change in the comparison value T due to the injection of the medicine. The amount of addition adjustment this time is determined. For example, when the comparison value T _m calculated this time is the threshold value H ₀ above, adding the adjustment amount of the drug becomes -B _6, for example.

That is, in the fourth calculation process, when the comparison value T _m is less than the threshold value L ₀ , the control device 43 determines the drug addition adjustment amount so as to increase the drug addition amount, and sets the comparison value T _m to the target value. to converge to the value _{T 0.} When the comparison value T _m is equal to or greater than the threshold value H ₀ , the control device 43 determines the drug addition adjustment amount so as to decrease the drug addition amount, and converges the comparison value T _m to the target value T ₀ . .

<Fifth arithmetic processing>
Step S121 is a comparison value _{T m} threshold _L 1 calculated this time _(L 0> _{L 1)} process of determining whether to become less. Controller 43 reads the threshold value _{L 1} from the storage device. If the comparison value _{T m} calculated this time is less than the threshold value _{L 1,} the control device 43, a Yes determination result in step S121. In this case, the process proceeds to step S122. On the other hand, when the comparison value _{T m} calculated this time is the threshold _{L 1} or more, the control device 43, and No judgment result in step S121. Note that the process of step S121 is executed every time the flowchart shown in FIG. 5 is executed.

Step S122 is processing for giving a warning. As an example, the control device 43 instructs the generation of a warning sound by a speaker provided in the sludge incineration facility 13 or instructs a warning display by a display device or a control device installed in the sludge incineration facility 13. That is, in the fifth arithmetic processing, with or without the addition of the drug, calculated comparison value T _m is determined whether less than the threshold L _1.

  In addition, after performing each process of a 1st calculation process to a 4th calculation process simultaneously, the control apparatus 43 performs the following processes. For example, step S104 of the first calculation process, step S107 of the second calculation process, step S110 of the third calculation process or step S113 of the same calculation process, step S116 of the fourth calculation process, and step S117 are determined No. In the case where it is determined, the control device 43 executes the process of step S119 and sets the current addition adjustment amount to ± 0. On the other hand, when the addition adjustment amount is determined by any one of the first calculation processing, the second calculation processing, the third calculation processing, or the fourth calculation processing, the control device 43 determines the determined addition adjustment amount. Is the addition adjustment amount this time. Then, the control device 43 outputs the determined addition adjustment amount to the supply device 54.

  As described above, the supply amount of the medicine is adjusted in the supply device 54 based on the addition adjustment amount obtained by the control device 43. At the time of this adjustment, if the added amount of the medicine becomes 0 or less by the input addition adjustment amount, the supply device 54 stops the supply of the medicine to the sewage sludge. Further, when the added amount of the drug exceeds 0 by the input addition adjustment amount, the supply device 54 starts supplying the drug to the sewage sludge.

  FIG. 6A is a diagram showing the relationship between the temperature and the heat flow based on the result of differential thermal analysis when no drug is introduced, and FIG. 6B is the case where a predetermined time has elapsed since the drug was introduced. It is a figure which shows the relationship between temperature and heat flow based on the result of differential thermal analysis. As shown in FIG. 6A, for example, when the first set value T1 that limits the temperature range is set to 750 ° C., an endothermic peak having a bottom of about 560 ° C. peak difference is about 520 ° C. Excluded, the endothermic peak is observed only for substances at 750 ° C. or higher.

The endothermic peak of the melting point component having a temperature higher than the first set value T1, for example, the first set value T2n, in other words, the target temperature field is about 775 ° C. For example, when the combustion of the incinerator, and sets the target value T ₀ of the lowest melting point 800 ° C. Even lower melting point material, a first set value T2n, since lower than the target value T0, the In such a case, a predetermined amount of medicine is introduced. As shown in FIG. 6 (b), the first set value T2n changes to about 800 ° C. when a predetermined amount of the chemical is put into the sewage sludge. Therefore, the temperature at which the endothermic peak starts to drop increases. In addition, it is thought that the fall start temperature of an endothermic peak rises by making low the content rate of the component of phosphorus and the compound of phosphorus contained in sewage sludge by injection | pouring of a chemical | medical agent.

  Therefore, it is possible to capture the phase change from the solid phase to the liquid phase of the low melting point substance in the ash based on the temperature at which the endothermic peak starts to decrease, which is obtained using the results of differential thermal analysis, and is used when incinerating sewage sludge. The amount of chemical added can be adjusted and the supply of chemicals can be started or stopped, so that it does not need to investigate the compounds and colors contained in the accumulated incineration ash and adhere to the exhaust gas flow path after incineration. Accumulation or performance deterioration of the fluid sand can be estimated, and addition and stop of the addition of the medicine and adjustment of the addition amount of the medicine to be added can be performed based on the estimation result. Accordingly, it is possible to reliably prevent the flue blockage and the performance deterioration of the fluid sand caused by the incineration ash generated when the sewage sludge is incinerated adhere to and accumulate on the flue and the fluid sand.

In the first embodiment, as the fourth calculation process, the determination as to whether or not the comparison value is less than the threshold value L ₀ and the determination as to whether or not the comparison value T is equal to or greater than the threshold value H ₀ are performed as one calculation process. However, these determination processes can also be performed individually.

  In the first embodiment, based on the results of differential thermal analysis, it is determined whether or not a chemical is added to sewage sludge and whether or not the amount of addition to be added is adjusted, but it is necessary to limit to this. It is also possible to adjust the internal temperature of the fluidized incinerator 37. Hereinafter, the case where the internal temperature of the fluidized incinerator 37 is adjusted based on the result of differential thermal analysis will be described as a second embodiment.

Second Embodiment
The water purification system in the second embodiment has the same configuration as the water purification system in the first embodiment. Therefore, in the following description, description is abbreviate | omitted about each structure of a water purification system, and about the structure same as 1st Embodiment, the same code | symbol is attached | subjected and demonstrated.

  Hereinafter, based on the result of the differential thermal analysis, the flow of processing when the internal temperature of the fluidized incinerator 37 is adjusted by logic control will be described based on the flowchart of FIG. Note that the control method may be logical control shown as an example, for example, PID control, FUZZY inference, etc., for example, a drop start temperature when there is a peak difference that is a heat flow value difference of an endothermic peak larger than the threshold value Pth, etc. It may be based on linear control (for example, feedback control). Also, a plurality of control methods can be used in combination.

In FIG. 7, symbols V _{1 to} V ₄ and symbols U ₁ to U ₆ are used for the calculated temperature adjustment amount.

  Step S201 is processing for performing differential thermal analysis. Note that the process of step S201 is the same process as step S101.

  Step S202 is processing for calculating the drop start temperature T. Note that the process of step S202 is the same process as step S102.

Step S203 is processing to determine whether or not the comparison value _Tm has been calculated. When the comparison value T is calculated in step S202, the control device 43 sets the determination result in step S203 to Yes. In this case, the process after step S204 is performed. On the other hand, when the comparison value _Tm is not calculated, the control device 43 sets the determination result in step S103 to No. In this case, the process of the flowchart shown in FIG. In addition, when the result of the determination process in step S103 is No, processes such as changing the addition amount of the chemical liquid and starting and stopping the chemical liquid are not executed.

  When it determines with Yes by the process of step S203, the control apparatus 43 performs the several process shown below simultaneously. Hereinafter, the process from step S204 to step S206 is the first calculation process, the process from step S207 to step S209 is the second calculation process, the process from step S210 to step S214 is the third calculation process, and the process from step S215 to step S218 is performed. This is referred to as a fourth calculation process. Moreover, the control apparatus 43 performs the 5th calculation process shown to step S221 and step S222 other than the 1st-4th calculation process mentioned above.

<First calculation process>
Step S204, the comparison value T _m calculated this time is the process of determining whether to exceed the target value T _0. If the comparison value _{T m} calculated this time exceeds the target value _{T 0,} the control unit 43, a Yes determination result in step S204. In this case, the process proceeds to step S204. On the other hand, when the comparison value _{T m} calculated this time is equal to or less than the target value _{T 0,} the control device 43, and No the decision result in the step S204.

Step S205 is a comparison value T _m calculated this time is the last calculated comparison value T _m-1 or more, and the process of determining whether it has a temperature adjustment amount of the previous a positive value. The control device 43 reads the comparison value T _m−1 calculated last time and the previous temperature adjustment amount from the storage device. In comparison value T _m calculated this time is the last calculated comparison value T _m-1 or more, and if the temperature adjustment amount and the previous positive value, the control unit 43, a Yes determination result in step S205. In this case, the process proceeds to step S206. On the other hand, in the comparison value T _m calculated this time is the last calculated comparison value T _m-1 or more, and if not the temperature adjustment amount and the previous positive value, the control unit 43, No the result of the determination in step S205 And

Step S206 is processing for determining the current temperature adjustment amount. Controller 43 reads previous or temperature adjustment amount in step S205, the other comparison values T _m and the target value T ₀ is calculated, the variation in the internal temperature of the fluidized incinerator 37 which varies by pouring the drug The current temperature adjustment amount is determined based on the above. For example, the results of differential thermal analysis after the temperature adjustment amount + V ₁ of the last, exceeded the comparison value T _m calculated this time is the target value T _0, and this time the calculated comparison value T _m is the comparison value previously calculated When it is equal to or higher than T _m−1 , it can be determined that the internal temperature of the fluidized incinerator 37 is high. In such a case, the temperature adjustment amount is, for example, −U ₁ .

That is, in the first calculation process, the comparison value T _m exceeds the target value T ₀ , the comparison value T _m calculated this time is equal to or more than the comparison value T _m−1 calculated last time, and the previous temperature adjustment amount is positive. when, to determine the temperature adjustment amount to lower the internal temperature of the fluidized incinerator 37 converges the comparison value T _m to a target value T _0.

<Second arithmetic processing>
Step S207, the comparison value T _m calculated this time is the process of determining whether it is less than the target value T _0. If the comparison value _{T m} calculated this time is less than the target value _{T 0,} the control unit 43, a Yes determination result of the step S207. In this case, the process proceeds to step S208. On the other hand, when the comparison value _{T m} calculated this time becomes the target value _{T 0} or more, the control device 43, and No judgment result of the step S207.

Step S208 is a comparison value T _m-1 below a comparison value T _m calculated this time is previously calculated, a and process of determining whether the temperature adjustment amount and the previous negative value. The control device 43 reads the comparison value T _m−1 calculated last time and the previous temperature adjustment amount from the storage device. Comparison value T _m calculated this time is the comparison value T _m-1 below the previously calculated, and if the temperature adjustment amount and the previous negative value, the control unit 43, a Yes determination result in step S208. In this case, the process proceeds to step S209. On the other hand, less than the comparison value T _m-1 comparison value T _m calculated this time is previously calculated, and if not the temperature adjustment amount and the previous negative value, the control unit 43, No the result of the determination in step S208 And

Step S209 is processing for determining the current temperature adjustment amount. Controller 43 reads previous or temperature adjustment amount in step S208, the other comparison values T _m and the target value T ₀ is calculated, the variation in the internal temperature of the fluidized incinerator 37 which varies by pouring the drug The current temperature adjustment amount is determined based on the above. For example, comparison value T _m based on the results of the differential thermal analysis after the addition adjustment amount + V ₂ of the last is less than the target value T _0, and this time the calculated comparison value T _m is calculated last time comparison value T _m- When it is ₁ or less, it can be determined that the internal temperature of the fluidized incinerator 37 is low. In such a case, the temperature adjustment amount is, for example, + U ₂ .

That is, in the second calculation process, when the comparison value T _m is less than the target value T ₀ , the currently calculated comparison value T _m is less than or equal to the previously calculated comparison value T _m−1 , and the previous temperature adjustment amount is negative. determines the temperature adjustment amount to raise the internal temperature of the fluidized incinerator 37 converges the comparison value T _m to a target value T _0.

<Third arithmetic processing>
Step S210, the comparison value T _m calculated this time is the process of determining whether it is equal to the target value T _0. If the comparison value _{T m} calculated this time is the same as the target value _{T 0,} the control unit 43, a Yes determination result of the step S210. In this case, the process proceeds to step S211. On the other hand, when the comparison value T _m calculated this time is not the same as the target value T _0, the control device 43, and No judgment result of the step S210.

Step S211 is processing for determining whether or not the currently calculated comparison value _Tm exceeds the previously calculated comparison value _Tm-1 and the previous temperature adjustment amount is a positive value. The control device 43 reads the comparison value T _m−1 calculated last time and the previous temperature adjustment amount from the storage device. Exceeds a comparison value T _m-1 comparison value T _m calculated this time is previously calculated, and if the temperature adjustment amount and the previous positive value, the control unit 43, a Yes determination result in step S211. In this case, the process proceeds to step S212. On the other hand, less than the comparison value T _m-1 comparison value T _m calculated this time is previously calculated, and if not the temperature adjustment amount and the previous positive value, the control unit 43, No the result of the determination in step S211 And In this case, the process proceeds to step S213.

Step S212 is processing for determining the current temperature adjustment amount. Controller 43 reads previous or temperature adjustment amount in step S211, the other comparison values T _m and the target value T ₀ is calculated, the variation in the internal temperature of the fluidized incinerator 37 which varies by pouring the drug The current temperature adjustment amount is determined based on the above. For example, comparison value T _m calculated is the same as the target value T ₀ on the basis of the differential thermal analysis after the temperature adjustment amount + V ₃ of the previous and current calculated comparison value T _m is the comparison value T _m previously calculated _{When −1} is exceeded, it can be determined that the internal temperature of the fluidized incinerator 37 is high. In such a case, the temperature adjustment amount is, for example, −U ₃ .

Step S213 is processing for determining whether or not the currently calculated comparison value _Tm is less than the previously calculated comparison value _Tm−1 and whether the previous temperature adjustment amount is a negative value. The control device 43 reads the comparison value T _m−1 calculated last time and the previous temperature adjustment amount from the storage device. Comparison value T _m calculated this time is less than the comparison value T _m-1 previously calculated, and if the temperature adjustment amount and the previous negative value, the control unit 43, a Yes determination result in step S213. In this case, the process proceeds to step S214. On the other hand, when the comparison value T _m calculated this time is the same as the comparison value T _m-1 previously calculated, and if not the temperature adjustment amount and the previous negative value, the control device 43 in step S213 The determination result is No.

Step S214 is processing for determining the current temperature adjustment amount. Controller 43 reads previous or temperature adjustment amount in step S213, the other comparison values T _m and the target value T ₀ is calculated, the variation in the internal temperature of the fluidized incinerator 37 which varies by pouring the drug The current temperature adjustment amount is determined based on the above. For example, the comparison value T _m calculated based on the differential thermal analysis after setting the previous temperature adjustment amount −V ₄ is the same as the target value T ₀ , and the comparison value T _m calculated this time is the comparison value T calculated last time. When it is less than _m−1 , it can be determined that the internal temperature of the fluidized incinerator 37 is low. In such a case, the temperature adjustment amount is, for example, + U ₄ .

That is, in the third calculation process, the comparison value T _m is the same as the target value T ₀ , the currently calculated comparison value T _m exceeds the previously calculated comparison value T _m−1 , and the previous temperature adjustment amount is positive. If the determines the temperature adjustment quantity to lower the internal temperature of the fluidized incinerator 37 converges the comparison value T _m to a target value T _0. Further, when the comparison value T _m is the same as the target value T ₀ , the currently calculated comparison value T _m is less than the previously calculated comparison value T _m−1 , and the previous temperature adjustment amount is negative, the fluidized incinerator 37. internal temperature to determine the temperature adjustment amount so as to increase the converges the comparison value T _m to a target value T _0.

<Fourth arithmetic processing>
Step S215 is a comparison value T _m calculated this time is determined whether or not it is less than the threshold L _0. Here, the threshold value L ₀ is a lower limit side threshold value set for the target value T ₀ . When comparison value _{T m} calculated this time is less than the threshold _{L 0,} the control unit 43, a Yes determination result in step S215. In this case, the process proceeds to step S216. On the other hand, when the comparison value _{T m} calculated this time is not less than the threshold value _{L 0,} the control device 43, and No the decision result in the step S214. In this case, the process proceeds to step S217.

Step S216 is processing for determining the current addition adjustment amount. Control device 43, other comparative values T _m and the target value T ₀ is calculated, the drug based on such variation in the internal temperature of the fluidized incinerator 37 which changes by introducing, determines the temperature adjustment quantity of this To do. For example, when the comparison value T _m calculated this time is less than the threshold L _0, the temperature adjustment amount is for example + U _5.

Step S217 is a comparison value T _m calculated this time is determined whether or not the threshold value H ₀ above. Here, the threshold value H ₀ is an upper limit side threshold value set for the target value T ₀ . If the comparison value _{T m} calculated this time becomes the threshold value _{H 0} above, the control device 43, a Yes determination result in step S217. In this case, the process proceeds to step S218. On the other hand, when the comparison value _{T m} calculated this time is less than the threshold value _{H 0,} the control device 43, and No the decision result in the step S217.

Step S218 is processing for determining the current addition adjustment amount. Control device 43, other comparative values T _m and the target value T ₀ is calculated, the drug based on such variation in the internal temperature of the fluidized incinerator 37 which changes by introducing, determines the temperature adjustment quantity of this To do. For example, when the comparison value T _m calculated this time is less than the threshold value H _0, temperature adjustment amount is for example -U _6.

In other words, in the fourth calculation process, if the comparison value T _m is less than the threshold L _0, to determine the temperature adjustment amount to raise the internal temperature of the fluidized incinerator 37, the target value T ₀ the comparison value T _m Converge. Also, if the comparison value T _m is the threshold H ₀ above, to determine the temperature adjustment amount to lower the internal temperature of the fluidized incinerator 37 converges the comparison value T _m to a target value T _0.

<Fifth arithmetic processing>
Step S221 is a comparison value _{T m} threshold _L 1 calculated this time _(L 0> _{L 1)} process of determining whether to become less. Controller 43 reads the threshold value _{L 1} from the storage device. If the comparison value _{T m} calculated this time is less than the threshold value _{L 1,} the control device 43, a Yes determination result in step S221. In this case, the process proceeds to step S222. On the other hand, when the comparison value _{T m} calculated this time is the threshold _{L 1} or more, the control device 43, and No the decision result in the step S221. The process of step S221 is executed every time the flowchart shown in FIG. 7 is executed.

  Step S222 is processing for giving a warning. As an example, the control device 43 instructs the generation of a warning sound by a speaker provided in the sludge incineration facility 13 or instructs a warning display by a display device or a control device installed in the sludge incineration facility 13.

That is, in the fifth arithmetic processing, with or without the addition of the drug, calculated comparison value T _m is determined whether less than the threshold L _1.

  After simultaneously executing the processes from the first calculation process to the fourth calculation process, the control device 43 executes the following process. For example, when it is determined No in each process of step S204 of the first calculation process, step S207 of the second calculation process, step S210 or step S213 of the third calculation process, step S215 or step S217 of the fourth calculation process The control device 43 performs the process of step S219. By executing the process of step S219, the control device 43 sets the current temperature adjustment amount to ± 0. On the other hand, when the temperature adjustment amount is determined by any one of the first calculation process, the second calculation process, the third calculation process, or the fourth calculation process, the controller 43 determines the determined temperature adjustment amount. Is the current temperature adjustment amount. Then, the control device 43 controls the internal temperature of the fluidized incinerator 37 based on the determined temperature adjustment amount.

  Thus, the control device 43 adjusts the internal temperature of the fluidized incinerator 37 using the result of the differential thermal analysis. Therefore, the incineration state of the sewage sludge is controlled by adjusting the temperature inside the fluidized incinerator by the control device 43. As a result, it is possible to prevent the occurrence of an event in which the incineration ash generated when the sewage sludge is incinerated adheres and accumulates in the flow path of the incineration exhaust gas and the event that the performance of the fluidized sand deteriorates.

  In the first embodiment, the case where the start or stop of the addition of the drug and the adjustment of the amount of the drug to be added is adjusted based on the temperature at which the endothermic peak starts to be lowered using the result of the differential thermal analysis is disclosed. In the second embodiment, the case where the internal temperature of the fluidized incinerator is adjusted based on the temperature at which the endothermic peak starts to be lowered using the result of the differential thermal analysis is disclosed. However, based on the temperature at which the endothermic peak starts to be calculated using the results of differential thermal analysis, both the addition of the drug and the adjustment of the addition amount of the drug to be added and the adjustment of the internal temperature of the fluidized incinerator are performed simultaneously. Thus, it becomes possible to reliably prevent the blockage of the flue and the performance deterioration of the fluidized sand. In addition to this, one of adjustment of the start or stop of the addition of the drug, the adjustment of the addition amount of the drug to be added, and the adjustment of the internal temperature of the fluidized incinerator may be selectively executed.

  As described above, in the present embodiment, since the start and stop of the injection of the medicine or the supply amount of the medicine to be supplied is adjusted based on the temperature at which the endothermic peak starts to be calculated using the results of the differential thermal analysis. Before the event of increasing pressure drop in the flue begins to occur, it is possible to foresee the attachment of ash causing flue blockage and poor flow. At the same time, it excludes substances that do not change phase that are not related to adhesion, which is the temperature at which the endothermic peak starts to fall, so it is possible to accurately capture the event as an assumption that ash components are attached to fluid sand. .

  In the present embodiment, the supply device automatically starts addition of a drug or automatically adjusts the amount of drug to be added. However, it is also possible to manually perform the addition of the drug by the supply device and the adjustment of the added amount of the drug to be added based on the temperature at which the endothermic peak starts to be lowered using the result of the differential thermal analysis and the change thereof. .

  In this embodiment, assuming the case where the flue has not been blocked, based on the endothermic peak descent start temperature obtained using the results of differential thermal analysis, the start and stop of the addition of the drug, and the drug being added By adjusting the amount of addition, the flue blockage caused by the incineration ash adhering to and accumulating on the flue, and the incineration ash adhering to the surface of the fluid sand, the fluid sand particles are bonded and granulated. The poor flow caused by this is prevented. However, if the endothermic degree based on the endothermic peak drop starting temperature obtained using the differential thermal analysis results in a significantly high value, this prevention effect is delayed and the risk of flue blockage and poor flow is high. It is shown that. Therefore, when the endothermic degree based on the endothermic peak descent start temperature obtained using the calculated differential thermal analysis result becomes extremely high, the control device 43 performs control so that the sludge incineration facility 13 is temporarily stopped. It is also possible to do. Each of the predetermined values described above is a value obtained from past empirical rules and the like. The value is significantly higher than the respective upper limit value, while the significantly lower predetermined value is less than the respective lower limit value. Preferably there is.

  In this case, warning may be generated by generating a warning sound by a speaker provided in the sludge incineration facility or by a warning display by a display device installed in the sludge incineration facility 13 or a display device connected to the control device.

  Also, in the incineration of sewage sludge in the fluidized incinerator 37, several differential thermal analysis locations in the flue from the fluidized incinerator 37 to the dust collector 39 are installed, and by detecting the endothermic peak at the location where ash does not normally adhere, If it can be inferred that incineration ash has adhered and accumulated in the flue, and if the incineration ash has adhered to and accumulated on the inner surface of the flue so that the flue is blocked, a fluidized bed is formed. It can be inferred that incineration ash adheres to the surface of the fluidized sand and the flow failure is about to occur, and the start and stop of the addition of the drug and the amount of addition can be determined based on the estimation result. As a result, it becomes possible to prevent incineration ash and components of the incineration ash from adhering to and laminating on the surface of the fluid sand particles. In addition, even when chemicals are added, it is determined whether or not the incineration exhaust gas flue has pressure deposits in the exhaust gas flow path after incineration, and at the same time, Since the addition amount can be adjusted, it is possible to suppress the usage amount of the chemical at the time of incineration of the sewage sludge 25, and it is possible to suppress the cost related to the chemical.

  Further, the control for temporarily stopping the incineration facility 13 may not be an automatic stop, but a warning sound generated by a speaker provided in the sludge incineration facility or a display device or a control device installed in the sludge incineration facility 13 may be used. The warning display by the connected display device prompts the incineration facility operator to determine the situation, and the incineration facility operator determines that it is necessary to take measures such as temporarily stopping the incineration facility 13 and cleaning the flue or replacing the fluidized sand. In this case, the incineration facility may be stopped by manual operation of the incineration facility operator.

  In this embodiment, the compound contained in the sludge-derived incineration exhaust gas that adheres and accumulates on the equipment and elements constituting the sludge incineration equipment is regarded as a harmful compound, and the harmful compound adheres to the equipment and elements of the sludge incineration equipment. It is intended for a fluid incinerator because it aims to provide a sludge incineration facility and a sludge incineration method that can supply an appropriate amount of chemicals that prevent clogging of exhaust gas flow paths and flow defects caused by accumulation. However, incinerators other than fluidized incinerators (for example, stalker type) are limited to the purpose of preventing the blockage of the flue caused by the incineration ash generated when the sewage sludge is incinerated. ) Does not deny application to.

DESCRIPTION OF SYMBOLS 10 ... Water purification system, 11 ... Sewage purification equipment, 12 ... Sludge treatment equipment, 13 ... Sludge incineration equipment, 37 ... Fluid incinerator, 38 ... Air preheater, 39 ... Dust collector, 43 ... Control device, 54 ... Supply Apparatus, 56 ... thermogravimetric / differential thermal analyzer

Claims (18)

An incinerator for incinerating sewage sludge;
Analytical means for performing differential thermal analysis using incineration ash generated when incinerating the sewage sludge,
Based on the results of the differential thermal analysis, a first instruction indicating the start or stop of the supply of chemicals to prevent the deposition of harmful compounds on the equipment and elements of the sludge incineration facility, or in the incinerator A control unit that issues any one of the second instructions to adjust the temperature of
A sludge incineration facility characterized by comprising: An incinerator for incinerating sewage sludge;
Analytical means for performing differential thermal analysis using incineration ash generated when incinerating the sewage sludge,
Based on the results of the differential thermal analysis, a first instruction to adjust the supply amount of the chemical to prevent the deposition of harmful compounds on the equipment and elements of the sludge incineration facility to the sewage sludge, or the temperature in the incinerator A control unit that issues any one of the second instructions for adjusting
A sludge incineration facility characterized by comprising: In the sludge incineration facility according to claim 1 or claim 2,
The control unit detects a decrease start temperature of the endothermic peak of the incinerated ash generated in a predetermined temperature range from the result of the differential thermal analysis, and compares the detected decrease start temperature with a preset target value. Then, either the first instruction or the second instruction is given. In the sludge incineration facility according to claim 3,
Air preheating for preheating the combustion air by exchanging heat between the combustion exhaust gas discharged from the incinerator for incinerating the sewage sludge and the combustion air sent to the incinerator for incinerating the sewage sludge Have a bowl,
The control unit sets a temperature range for detecting the descent start temperature based on the temperature inside the incinerator for incinerating the sewage sludge and the temperature of the combustion exhaust gas discharged from the air preheater. Sludge incineration equipment. In the sludge incineration facility according to claim 4,
The control unit sets a lower limit value of the temperature range based on a temperature inside the incinerator that incinerates the sewage sludge and a temperature of combustion exhaust gas discharged from the air preheater. Incineration equipment. In the sludge incineration facility according to any one of claims 3 to 5,
The control unit, in addition to comparing the newly calculated drop start temperature and the target value, compares the drop start temperature calculated at the previous comparison with the newly calculated drop start temperature. A sludge incineration facility characterized by being conducted. In the sludge incineration facility according to any one of claims 1 to 6,
The incinerator for incinerating the sewage sludge is a fluidized incinerator that forms a fluidized bed with a fluidized medium by blown air, and incinerates the sewage sludge to be charged in the fluidized bed. Incineration equipment. In the sludge incineration facility according to any one of claims 1 to 6,
The chemical is supplied to the sewage sludge from when the sewage sludge is generated to when it is put into the incinerator for incinerating the sewage sludge, or directly supplied to the incinerator for incinerating the sewage sludge. Sludge incineration equipment characterized by being In the sludge incineration facility according to claim 8,
The chemical is at least one of before the sewage sludge is concentrated, before the sewage sludge is dehydrated, before the sewage sludge is dried, or before being put into the incinerator for incinerating the sewage sludge. The sludge incineration facility is characterized in that it is supplied to the sewage sludge at one timing. Incineration of sewage sludge using an incinerator for incinerating sewage sludge;
Performing differential thermal analysis using incineration ash obtained by incineration of the sewage sludge,
Based on the result of the differential thermal analysis, the first instruction indicating the start or stop of the supply of the chemical to the sewage sludge with the agent that prevents the deposition of harmful compounds on the equipment and elements of the sludge incineration facility, or the sewage sludge A step of performing any one of the second instructions for adjusting the temperature in the incinerator to be incinerated;
The sludge incineration method characterized by having. Incineration of sewage sludge using an incinerator for incinerating sewage sludge;
Performing differential thermal analysis using incineration ash obtained by incineration of the sewage sludge,
Based on the result of the differential thermal analysis, the first instruction to adjust the supply amount of the chemical that prevents the deposition and deposition of harmful compounds on the equipment and elements of the sludge incineration facility, or the temperature in the incinerator that incinerates the sewage sludge A step of giving any instruction of the second instruction to adjust
The sludge incineration method characterized by having. In the sludge incineration method of Claim 10 or Claim 11,
The step of performing the instruction of either the first instruction or the second instruction is detected from a result of the differential thermal analysis, a step of detecting a temperature at which the endothermic peak of the incinerated ash that falls within a predetermined temperature range starts falling. A method of comparing the descent start temperature with a preset target value. In the sludge incineration method of Claim 12,
The comparison step uses the temperature inside the incinerator for incinerating the sewage sludge and the temperature of the combustion exhaust gas after preheating the combustion air by heat exchange in the air preheater, to determine the endothermic peak of the incineration ash. A sludge incineration method comprising a step of setting a temperature range for detecting the descending start temperature. In the sludge incineration method of Claim 13,
The step of setting the temperature range sets a lower limit value of the temperature range based on the temperature inside the incinerator for incinerating the sewage sludge and the temperature of the combustion exhaust gas discharged from the air preheater. Sludge incineration method. The sludge incineration method according to any one of claims 12 to 14,
In the comparing step, in addition to a comparison between the newly calculated lowering start temperature and the target value, a comparison between the lowering start temperature calculated at the previous comparison and the newly calculated lowering start temperature. The sludge incineration method characterized by performing. The sludge incineration method according to any one of claims 10 to 15,
The step of incinerating the sewage sludge is a step of forming a fluidized bed of fluidized sand by air blown into a fluidized incinerator and incinerating the sewage sludge to be charged into the fluidized incinerator in the fluidized bed. The sludge incineration method characterized by this. The sludge incineration method according to any one of claims 10 to 16,
A sludge incineration method further comprising a step of supplying the chemical to the incinerator for incinerating the sewage sludge until the sewage sludge is put into an incinerator for incinerating the sewage sludge. The sludge incineration method according to claim 17,
The step of supplying the chemical is performed before concentrating the sewage sludge, before dehydrating the sewage sludge, before drying the sewage sludge, or putting the sewage sludge into an incinerator that incinerates the sewage sludge. A sludge incineration method, wherein the method is performed at least at one of the timings before the operation.

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