Drug addition index calculation method

Abstract

To provide a chemical addition index calculation method for calculating an index capable of accurately evaluating an addition amount of a chemical to an object to be incinerated.SOLUTION: A first value related to an amount of phosphorus contained in an object to be incinerated, a second value related to an amount of phosphorus bonded to a predetermined metal, a third value related to an amount of sulfur contained in the object to be incinerated, and a fourth value related to an amount of calcium to be charged into the object to be incinerated are acquired, and an evaluation index for the amount of calcium to be charged into the object to be incinerated is calculated on the basis of the acquired first, second, third, and fourth values.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for calculating a drug addition index. [Background technology]

[0002] For example, various techniques have been proposed for treating exhaust gas from incinerators that incinerate sewage sludge (hereinafter also simply referred to as sludge or material to be incinerated) (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-213885 Summary of the Invention [Problem to be solved by the invention]

[0004] The exhaust gas emitted from such an incinerator contains, for example, sulfur oxides (SOx), which cause low-temperature corrosion in facilities such as the incinerator and piping. Therefore, in an incineration system having an incinerator (hereinafter simply referred to as an incineration system), it is necessary to suppress the generation of sulfur oxides in the incinerator, for example.

[0005] Here, in an incineration system, it is preferable to efficiently add chemicals (hereinafter simply referred to as chemicals) that can suppress the generation of sulfur oxides, for example, from the viewpoint of cost reduction. In other words, in an incineration system, it is preferable to suppress the amount of chemicals added to the material to be incinerated while suppressing the generation of sulfur oxides. Therefore, in an incineration system, an index that can accurately evaluate the amount of chemicals added to the material to be incinerated is desired. [Means for solving the problem]

[0006] The method for calculating a chemical addition index in the present disclosure obtains a first value relating to the amount of phosphorus contained in the material to be incinerated, a second value relating to the amount of phosphorus that bonds with a specified metal, a third value relating to the amount of sulfur contained in the material to be incinerated, and a fourth value relating to the amount of calcium to be added to the material to be incinerated, and calculates an evaluation index for the amount of calcium to be added to the material to be incinerated based on the obtained first value, second value, third value, and fourth value. [Effects of the Invention]

[0007] According to the method for calculating an agent addition index in the present disclosure, it is possible to calculate an index that enables accurate evaluation of the amount of agent added to the material to be incinerated. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of an incineration system 100 according to the first embodiment. [Figure 2] FIG. 2 is a diagram illustrating the hardware configuration of the control device 10. As shown in FIG. [Figure 3] FIG. 3 is a flowchart illustrating the method for calculating the medicine addition index in the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating a specific example of step S3. [Figure 5] FIG. 5 is a diagram illustrating a specific example of step S3. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, such descriptions should not be interpreted in a limiting sense, and do not limit the subject matter described in the claims. Furthermore, various changes, substitutions, and modifications can be made without departing from the spirit and scope of the present disclosure. Furthermore, different embodiments can be combined as appropriate.

[0010] [Incineration system 100 in the first embodiment] First, an incineration system 100 in the first embodiment will be described. Figure 1 is a diagram illustrating an example of the configuration of the incineration system 100 in the first embodiment. Note that the arrangement positions, lengths, and numbers of pipes shown below are examples and are not limited to these.

[0011] As shown in FIG. 1, the incineration system 100 includes, for example, a blower B1, an incinerator 1, a storage tank 2, a pump P1, a dust collector 3, and a control device 10.

[0012] The blower B1 is, for example, a device that supplies air (hereinafter also referred to as combustion air) to the incinerator 1 via a line L21. The line L21 is, for example, a pipe that connects the outlet side of the blower B1 with the inlet side of the combustion air in the incinerator 1. Specifically, the blower B1 is, for example, a device that has the function of blowing air, such as a fan or a blower.

[0013] The incinerator 1 is, for example, a fluidized bed incinerator that incinerates sludge (dewatered cake) supplied via line L11, and has a so-called fluidized bed 1a. Line L11 is, for example, a pipe that connects upstream equipment of the incinerator 1 (for example, a sludge dryer) with the sludge inlet side of the incinerator 1. The following description will be given assuming that the incinerator 1 is a fluidized bed incinerator, but the incinerator 1 may be, for example, various types of incinerators other than a fluidized bed incinerator.

[0014] The reservoir 2 stores, for example, a chemical agent containing calcium (hereinafter also simply referred to as a chemical agent). The chemical agent may be, for example, a chemical agent containing calcium hydroxide (slaked lime: Ca(OH)2). It may also be a chemical agent containing calcium carbonate (CaCO3). It may also be a chemical agent containing calcium chloride (CaCl2).

[0015] Pump P1 is disposed, for example, on line L31, and supplies (adds) the chemical stored in storage tank 2 to incinerator 1 (sludge in incinerator 1). Line L31 is, for example, a pipe that connects storage tank 2 with the chemical inlet side of incinerator 1.

[0016] The following description will be given of a case where the chemical agent is supplied to the sludge in the incinerator 1, but the present invention is not limited to this. Specifically, the chemical agent may be supplied to the sludge before it is supplied to the incinerator 1 (for example, the sludge in the line L11).

[0017] A feeder (not shown) may be provided in place of the pump P1 in the line L31. In this case, the feeder may supply (add) the chemical stored in the storage tank 2 to the incinerator 1 (the sludge in the incinerator 1), for example.

[0018] The control device 10 controls the amount of chemicals supplied to the incinerator 1 (for example, the amount of chemicals supplied per unit time) by controlling the pump P1, for example.

[0019] The dust collector 3 is disposed, for example, downstream of the incinerator 1, and collects incineration ash (hereinafter also simply referred to as incineration ash) contained in the exhaust gas G1 supplied from the incinerator 1 via line L1. The line L1 is, for example, a pipe connecting the outlet side of the exhaust gas G1 in the incinerator 1 with the inlet side of the dust collector 3. Specifically, the dust collector 3 may be, for example, a cyclone or a bag filter.

[0020] The dust collector 3 then supplies the exhaust gas G1 (the exhaust gas G1 after the incineration ash has been collected) to downstream equipment (not shown) of the dust collector 3, for example, via a line L2. The line L2 is, for example, a pipe that connects the outlet side of the exhaust gas G1 in the dust collector 3 with the downstream equipment.

[0021] The incineration system 100 may be provided with a heat exchanger (not shown) or the like that recovers the heat contained in the flue gas G1, for example, as equipment upstream or downstream of the dust collector 3. The incineration system 100 may also be provided with a heat exchanger (not shown) that recovers the heat contained in the flue gas G1, for example, as equipment downstream of the dust collector 3. XThe system may be equipped with a smoke washing tower (not shown) that removes components such as these by incorporating them into smoke washing water, and a chimney (not shown) that releases the exhaust gas G1 cleaned in the smoke washing tower to the outside.

[0022] The dust collector 3 also discharges incineration ash via, for example, a line L3. The line L3 is, for example, a pipe that connects the incineration ash outlet side of the dust collector 3 with a storage container (not shown) for the incineration ash.

[0023] That is, in the incineration system 100, for example, calcium is added to the sludge in the incinerator 1, so that the sulfur component-containing gas generated by the combustion or gasification of the sludge is absorbed by the calcium, thereby reducing the amount of sulfur oxides produced.

[0024] As a result, in the incineration system 100, for example, it becomes possible to suppress the amount of sulfur oxides generated in the incinerator 1.

[0025] In addition, in the incineration system 100, for example, a chemical agent is added to the sludge in the incinerator 1, causing the phosphorus and calcium contained in the sludge to react with each other, thereby increasing the concentration of citrate-soluble phosphorus contained in the incineration ash.

[0026] This makes it possible for the incineration system 100 to increase the amount of citrate-soluble phosphate contained in the fertilizer produced using incineration ash, for example, thereby improving the effectiveness of the fertilizer when used.

[0027] Here, in the incineration system 100, for example, from the viewpoint of reducing costs, it is preferable to minimize the amount of chemicals (calcium) added to the sludge in the incinerator 1. That is, in the incineration system 100, it is preferable to minimize the amount of chemicals added to the sludge in the incinerator 1 while achieving at least one of, for example, making the sulfur removal rate in the incineration ash (hereinafter, desulfurization rate) equal to or greater than a predetermined value (hereinafter, also referred to as a first target value) and making the citrate-soluble phosphorus rate in the incineration ash equal to or greater than a predetermined value (hereinafter, also referred to as a second target value).

[0028] Therefore, the incineration system 100 in this embodiment performs a process (hereinafter also referred to as the index calculation process) to calculate an index that can be used, for example, to evaluate the amount of chemicals to be added to the sludge in the incinerator 1, and that can determine whether or not at least one of the following can be achieved: the desulfurization rate in the incineration ash is equal to or greater than a first target value; and the citrate-soluble phosphorus rate in the incineration ash is equal to or greater than a second target value.

[0029] Specifically, the index calculation process calculates an index that can determine whether it is possible to achieve, for example, a desulfurization rate in incineration ash equal to or greater than a first target value and a citrate-soluble phosphorus rate in incineration ash equal to or greater than a second target value.

[0030] Specifically, the incineration system 100 in this embodiment acquires, for example, a value relating to the amount of phosphorus contained in the sludge (hereinafter also referred to as a first value), a value relating to the amount of phosphorus contained in the sludge that binds to a predetermined metal (hereinafter also referred to as a second value), a value relating to the amount of sulfur contained in the sludge (hereinafter also referred to as a third value), and a value relating to the amount of calcium to be added (added) to the sludge (hereinafter also referred to as a fourth value). The predetermined metal is, for example, at least one of iron and aluminum. The first value is, for example, the number of moles of phosphorus contained in a predetermined amount of sludge before being added to the incinerator 1. The second value is, for example, the number of moles of a predetermined metal contained in a predetermined amount of sludge before being added to the incinerator 1. The third value is, for example, the number of moles of sulfur contained in a predetermined amount of sludge before being added to the incinerator 1. The fourth value is, for example, the number of moles of calcium contained in a predetermined amount of sludge before being added to the incinerator 1.

[0031] The first value may be calculated, for example, by dividing the mass of phosphorus measured for a predetermined amount of sludge before being charged into the incinerator 1 by the molecular weight of phosphorus. The second value may be calculated, for example, by dividing the mass of a predetermined metal measured for a predetermined amount of sludge before being charged into the incinerator 1 by the molecular weight of the predetermined metal. The third value may be calculated, for example, by dividing the mass of sulfur measured for a predetermined amount of sludge before being charged into the incinerator 1 by the atomic weight of sulfur. The fourth value may be calculated, for example, by dividing the mass of calcium measured for a predetermined amount of sludge before being charged into the incinerator 1 by the molecular weight of calcium.

[0032] Then, the incineration system 100 in this embodiment calculates an evaluation index (hereinafter simply referred to as the evaluation index) for the amount of calcium to be added to the sludge in the incinerator 1, for example, based on the acquired first value, second value, third value, and fourth value.

[0033] More specifically, the incineration system 100 in this embodiment calculates a value (hereinafter also referred to as a fifth value) by, for example, subtracting the second value from the first value. Then, the incineration system 100 in this embodiment calculates a value (hereinafter also referred to as a sixth value) by, for example, adding the fifth value and the third value. After that, the incineration system 100 in this embodiment calculates, for example, the ratio of the sixth value to the fourth value as an evaluation index.

[0034] Furthermore, the incineration system 100 in this embodiment calculates a value (hereinafter also referred to as the seventh value) by, for example, subtracting the third value from the fourth value. Then, the incineration system 100 in this embodiment calculates a value (hereinafter also referred to as the eighth value) by, for example, adding the second value and the seventh value. After that, the incineration system 100 in this embodiment calculates, for example, the ratio of the eighth value to the first value as an evaluation index.

[0035] That is, the incineration system 100 of this embodiment calculates an index that can evaluate, for example, whether the amount of calcium added to the sludge in the incinerator 1 is sufficient to react with the sulfur and phosphorus contained in the sludge fed into the incinerator 1. Furthermore, in this case, the incineration system 100 of this embodiment calculates an index that reflects, for example, the fact that part of the phosphorus contained in the sludge is used to react with the iron and aluminum contained in the sludge.

[0036] As a result, the incineration system 100 in this embodiment can reduce the amount of calcium (chemical) added to the sludge in the incinerator 1 while achieving, for example, at least one of the following: a desulfurization rate in the incineration ash equal to or greater than a first target value; and a citrate-soluble phosphorus rate in the incineration ash equal to or greater than a second target value.

[0037] Therefore, the incineration system 100 in this embodiment can suppress the occurrence of low-temperature corrosion in equipment such as the incinerator 1 where the sludge is incinerated and the line L1 through which the exhaust gas G1 passes, and can increase the concentration of citrate-soluble phosphorus contained in the incineration ash, while reducing the amount of calcium (chemical) added to the sludge in the incinerator 1.

[0038] Furthermore, in the incineration system 100 of this embodiment, for example, by adding calcium (a chemical) to the sludge in the incinerator 1, it is possible to reduce the amount of chemical that needs to be added to the wastewater discharged from the dust collector 3, for example, the amount of chemical (alkaline) that needs to be added to the scrubber wastewater.

[0039] The first value may be, for example, a value obtained by multiplying the number of moles of phosphorus contained in the sludge by a coefficient. The second value may be, for example, a value obtained by multiplying the number of moles of a predetermined metal contained in the sludge by a coefficient. The third value may be, for example, a value obtained by multiplying the number of moles of sulfur contained in the sludge by a coefficient. The fourth value may be, for example, a value obtained by multiplying the number of moles of calcium contained in the sludge by a coefficient.

[0040] [Control device 10 in the first embodiment] Next, the configuration of the control device 10 in the first embodiment will be described. Figure 2 is a diagram illustrating the hardware configuration of the control device 10.

[0041] 2, the control device 10 is, for example, an electronic device having an electronic circuit. Specifically, the control device 10 is, for example, a computer device having a CPU 101 which is a processor, a memory 102, a communication device 103, and a storage medium 104. Each unit is connected to each other via, for example, a bus 105.

[0042] The storage medium 104 has, for example, a program storage area (not shown) that stores a program 110 for performing the index calculation process. The storage medium 104 also has, for example, an information storage area 130 that stores information used when performing the index calculation process. The storage medium 104 may be, for example, a hard disk drive (HDD) or a solid state drive (SSD).

[0043] The CPU 101 performs the index calculation process by executing a program 110 loaded from the storage medium 104 to the memory 102, for example.

[0044] The communication device 103 accesses an operation terminal (not shown) through which an administrator inputs necessary information, for example, via a network (not shown) such as the Internet.

[0045] The control device 10 may have, for example, an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). The control device 10 may also include, for example, a PIC (Peripheral Interface Controller). The index calculation process may be executed in, for example, the FPGA or the ASIC.

[0046] [Index Calculation Process in the First Embodiment] Next, the index calculation process in the first embodiment will be described. Fig. 3 is a flowchart illustrating the index calculation process in the first embodiment. Note that, although the following description will be given of a case where the control device 10 performs the index calculation process, the index calculation process may also be performed manually by an operator, for example.

[0047] As shown in FIG. 3, the control device 10 acquires, for example, a first value, a second value, a third value, and a fourth value (step S1 in FIG. 3).

[0048] Specifically, the control device 10 obtains (calculates) a first value, for example, by dividing the mass of phosphorus measured for a predetermined amount of sludge before being charged into the incinerator 1 by the molecular weight of phosphorus. The control device 10 obtains (calculates) a second value, for example, by dividing the mass of a predetermined metal measured for a predetermined amount of sludge before being charged into the incinerator 1 by the molecular weight of the predetermined metal. The control device 10 obtains (calculates) a third value, for example, by dividing the mass of sulfur measured for a predetermined amount of sludge before being charged into the incinerator 1 by the atomic weight of sulfur. The control device 10 obtains (calculates) a fourth value, for example, by dividing the mass of calcium measured for a predetermined amount of sludge before being charged into the incinerator 1 by the molecular weight of calcium.

[0049] Note that, although the following description will be given of a case where the control device 10 acquires the number of moles of each of two types of metals (iron and aluminum) as the second value, the present invention is not limited to this. Specifically, the control device 10 may acquire the number of moles of each of three or more types of metals (for example, iron, aluminum, and magnesium).

[0050] Then, the control device 10 calculates the evaluation index based on the first value, the second value, the third value, and the fourth value acquired in step S1 (step S2 in FIG. 3), for example.

[0051] Specifically, the control device 10 calculates the evaluation index by substituting the first value, second value, third value, and fourth value acquired in step S1 into the following formula 1.

[0052]

number

[0053] In the above formula 1, [P2O5] represents the mass of phosphorus (P2O5) contained in a predetermined amount of sludge, and M(P2O5) represents the molecular weight of phosphorus (P2O5). Also, in the above formula 1, [Fe2O3] represents the mass of iron (Fe2O3) contained in a predetermined amount of sludge, and M(Fe2O3) represents the molecular weight of iron (Fe2O3). Also, in the above formula 1, [Al2O3] represents, for example, the mass of aluminum (Al2O3) contained in a predetermined amount of sludge, and M(Al2O3) represents the molecular weight of aluminum (Al2O3). Also, in the above formula 1, [total sulfur] represents, for example, the mass of sulfur contained in a predetermined amount of sludge, and M(sulfur) represents the atomic weight of sulfur. Also, in the above formula 1, [CaO] represents, for example, the mass of calcium (CaO) contained in a predetermined amount of sludge, and M(CaO) represents the molecular weight of calcium (CaO).

[0054] That is, in the above formula 1, [P2O5] / M(P2O5) indicates the number of moles of phosphorus (P2O5) contained in a given amount of sludge, [Fe2O3] / M(Fe2O3) indicates the number of moles of iron (Fe2O3) contained in a given amount of sludge, [Al2O3] / M(Al2O3) indicates the number of moles of aluminum (Al2O3) contained in a given amount of sludge, [total sulfur] / M(sulfur) indicates the number of moles of sulfur contained in a given amount of sludge, and [CaO] / M(CaO) indicates the number of moles of calcium (CaO) fed to incinerator 1.

[0055] Then, in step S2, for example, the control device 10 calculates the evaluation index by substituting the number of moles of phosphorus (P2O5) (first value) obtained in step S1 into [P2O5] / M(P2O5), substituting the number of moles of iron (Fe2O3) and the number of moles of aluminum (Al2O3) (second values) obtained in step S1 into [Fe2O3] / M(Fe2O3) and [Al2O3] / M(Al2O3), substituting the number of moles of sulfur (third value) obtained in step S1 into [total sulfur] / M(sulfur), and substituting the number of moles of calcium (CaO) (fourth value) obtained in step S1 into [CaO] / M(CaO).

[0056] That is, a portion of the phosphorus contained in the sludge fed into incinerator 1 reacts with, for example, the iron and aluminum contained in the sludge fed into incinerator 1, as shown in the following equations 2 and 3. Then, the phosphorus in the sludge fed into incinerator 1 that has not reacted with the iron or aluminum reacts with, for example, the calcium fed into the sludge in incinerator 1, as shown in the following equation 4. Furthermore, the sulfur contained in the sludge fed into incinerator 1 reacts with, for example, the calcium fed into the sludge in incinerator 1, as shown in the following equation 5.

[0057]

number

[0058]

number

[0059]

number

[0060]

number

[0061] Therefore, in the index calculation process of this embodiment, an index is calculated that can evaluate, for example, whether the amount of calcium added to the sludge in the incinerator 1 is sufficient to react with each of the sulfur and phosphorus contained in the sludge in the incinerator 1. Furthermore, in this case, the incineration system 100 of this embodiment reflects in the evaluation index, for example, that a portion of the phosphorus contained in the sludge in the incinerator 1 is used to react with the iron and aluminum contained in the sludge in the incinerator 1.

[0062] As shown in the above formula 2, 1 mole of iron combines with 1 mole of phosphorus. As shown in the above formula 3, 1 mole of aluminum combines with 1 mole of phosphorus. As shown in the above formula 4, 3 moles of calcium combine with 2 moles of phosphorus. As shown in the above formula 5, 1 mole of calcium combines with 1 mole of sulfur. Therefore, in the above formula 1, 2, 2, 2 / 3, and 2 / 3 are used as the coefficients of [P2O5] / M(P2O5), [Fe2O3] / M(Fe2O3), [Al2O3] / M(Al2O3), [total sulfur] / M(sulfur), and [CaO] / M(CaO), respectively.

[0063] Returning to FIG. 3, the control device 10 calculates the amount of calcium to be fed into the incinerator 1, for example, by using the evaluation index calculated in step S2 (step S3 in FIG. 3).

[0064] Specifically, the control device 10 identifies the threshold value corresponding to the desulfurization rate (e.g., the first target value) specified by the operator, for example, by referring to correspondence information (hereinafter also referred to as first correspondence information) that associates the desulfurization rate in the incinerator 1 with a threshold value for the evaluation index. The first correspondence information is, for example, information that is stored in advance in the information storage area 130. Specifically, the first correspondence information is, for example, an approximate straight line (hereinafter also referred to as the first approximate straight line) that indicates the correspondence relationship between the desulfurization rate in the incinerator 1 and the threshold value for the evaluation index.

[0065] Furthermore, the control device 10 identifies a threshold value corresponding to the citrate-soluble phosphorus rate (e.g., a second target value) designated by the operator, for example, by referring to correspondence information (hereinafter also referred to as second correspondence information) that associates the citrate-soluble phosphorus rate (hereinafter also referred to as simply the citrate-soluble phosphorus rate) of the phosphorus contained in the sludge input into the incinerator 1 with a threshold value for the evaluation index. The second correspondence information is, for example, information pre-stored in the information storage area 130. Specifically, the second correspondence information is, for example, an approximate straight line (hereinafter also referred to as the second approximate straight line) that indicates the correspondence relationship between the citrate-soluble phosphorus rate of the phosphorus contained in the sludge input into the incinerator 1 and the threshold value for the evaluation index.

[0066] In the following, a case where the second correspondence information is correspondence information that associates the soluble phosphorus rate with a threshold value for the evaluation index will be described, but the present invention is not limited to this. Specifically, the second correspondence information may be, for example, correspondence information that associates the soluble phosphorus rate of phosphorus contained in the sludge input into the incinerator 1 with a threshold value for the evaluation index. The operator may then specify the soluble phosphorus rate. A specific example of step S3 will be described below.

[0067] [Specific example of step S3 (1)] FIG. 4 is a diagram illustrating a specific example of step S3. Specifically, FIG. 4 is a graph illustrating specific examples of the first approximate line LN1 for the desulfurization rate and the second approximate line LN2 for the citrate-soluble phosphorus rate. The horizontal axis in the graph shown in FIG. 4 corresponds to the evaluation index (threshold value of the evaluation index). The vertical axis in the graph shown in FIG. 4 corresponds to the desulfurization rate and the citrate-soluble phosphorus rate. Below, we will explain a case where both the desulfurization rate in incineration ash to be equal to or greater than a first target value and the citrate-soluble phosphorus rate in incineration ash to be equal to or greater than a second target value are achieved.

[0068] The first approximate line LN1 shown in Fig. 4 indicates that the threshold value of the evaluation index is "1.3" when the desulfurization rate is "0.6", and that the threshold value of the evaluation index is "0.4" when the desulfurization rate is "0.8". The second approximate line LN2 shown in Fig. 4 indicates that the threshold value of the evaluation index is "0.8" when the citrate-soluble phosphorus rate is "0.9".

[0069] Therefore, for example, if the desulfurization rate specified by the operator is 0.6 or higher and the citrate-soluble phosphorus rate is 0.9 or higher, the control device 10 specifies 0.8, which is the smaller of 1.3, which is the threshold value of the evaluation index when the desulfurization rate is 0.6, and 0.8, which is the threshold value of the evaluation index when the citrate-soluble phosphorus rate is 0.9. In this case, the control device 10 specifies, for example, the amount of calcium to be input into the incinerator 1, such that the evaluation index (for example, the evaluation index calculated using Equation 1) is 0.8 or lower.

[0070] Furthermore, for example, when the desulfurization rate specified by the operator is 0.8 or more and the citrate-soluble phosphorus rate is 0.9 or more, the control device 10 specifies 0.4, which is the smaller of the threshold value of the evaluation index when the desulfurization rate is 0.8 and the threshold value of the evaluation index when the citrate-soluble phosphorus rate is 0.9. In this case, the control device 10 specifies, for example, the amount of calcium to be input into the incinerator 1, an amount that makes the evaluation index (for example, the evaluation index calculated using Equation 1) 0.4 or less.

[0071] Furthermore, for example, if only the desulfurization rate is specified by the operator and the specified desulfurization rate is 0.6 or higher, the control device 10 specifies 1.3, which is the threshold value of the evaluation index when the desulfurization rate is 0.6. In this case, the control device 10 specifies, for example, the amount of calcium to be input into the incinerator 1 such that the evaluation index (for example, the evaluation index calculated using Equation 1) is 1.3 or lower.

[0072] Furthermore, for example, if only the citrate-soluble phosphorus ratio is specified by the operator and the citrate-soluble phosphorus ratio specified by the operator is 0.9 or more, the control device 10 specifies 0.8, which is the threshold value of the evaluation index when the citrate-soluble phosphorus ratio is 0.9. In this case, the control device 10 specifies, for example, the amount of calcium to be input into the incinerator 1, such that the evaluation index (for example, the evaluation index calculated using Equation 1) is 0.8 or less.

[0073] In step S2, the control device 10 may calculate the evaluation index by, for example, substituting the first value, second value, third value, and fourth value acquired in step S1 into the following formula 6. That is, the control device 10 may calculate the evaluation index by, for example, using the following formula 6 instead of the above formula 1.

[0074]

number

[0075] In this manner, the incineration system 100 of this embodiment acquires, for example, a first value relating to the amount of phosphorus contained in the sludge, a second value relating to the phosphorus that binds to a predetermined metal contained in the sludge, a third value relating to the amount of sulfur contained in the sludge, and a fourth value relating to the amount of calcium to be added to the sludge.Then, the incineration system 100 of this embodiment calculates an evaluation index for the amount of calcium to be added to the sludge based on, for example, the acquired first, second, third, and fourth values.

[0076] Specifically, the incineration system 100 of this embodiment calculates the fifth value, for example, by subtracting the second value from the first value. Then, the incineration system 100 of this embodiment calculates the sixth value, for example, by adding the fifth value and the third value. After that, the incineration system 100 of this embodiment calculates the ratio of the sixth value to the fourth value as the evaluation index, for example.

[0077] Furthermore, the incineration system 100 in this embodiment calculates the seventh value, for example, by subtracting the third value from the fourth value. Then, the incineration system 100 in this embodiment calculates the eighth value, for example, by adding the second value and the seventh value. After that, the incineration system 100 in this embodiment calculates, for example, the ratio of the eighth value to the first value as an evaluation index.

[0078] As a result, the incineration system 100 in this embodiment can reduce the amount of calcium (chemical) added to the sludge in the incinerator 1 while achieving, for example, at least one of the following: a desulfurization rate in the incineration ash equal to or greater than a first target value; and a citrate-soluble phosphorus rate in the incineration ash equal to or greater than a second target value.

[0079] Specifically, the incineration system 100 in this embodiment can, for example, achieve the desulfurization rate in the incineration ash to a first target value or higher and the citrate-soluble phosphorus rate in the incineration ash to a second target value or higher, while reducing the amount of calcium (chemical) added to the sludge in the incinerator 1.

[0080] In addition, the index calculation process in this embodiment may be performed, for example, every time the desulfurization rate or citrate-soluble phosphorus rate is specified by the operator (specifying the first target value or the second target value), in other words, every time the desulfurization rate or citrate-soluble phosphorus rate specified by the operator is updated.

[0081] [Modification (1) of the index calculation process in the first embodiment] Next, a modified example of the index calculation process in the first embodiment (hereinafter also referred to as the first modified example) will be described.

[0082] In the index calculation process in the first embodiment, for example, the evaluation index is calculated based on a predetermined threshold corresponding to a predetermined citrate-soluble phosphorus rate in addition to a predetermined desulfurization rate. In contrast, in the index calculation process in the first modified example, the evaluation index is calculated based on a predetermined threshold corresponding to a predetermined sludge incineration temperature (for example, a target temperature for the sludge incineration temperature in the incinerator 1) in addition to a predetermined desulfurization rate.

[0083] Specifically, in step S3, the control device 10 identifies the threshold value corresponding to the incineration temperature designated by the operator by referring to correspondence information (hereinafter also referred to as third correspondence information) that associates the incineration temperature of sludge in the incinerator 1 with a threshold value for an evaluation index at which the degree of agglutination of incineration ash becomes equal to or less than a predetermined value. The degree of agglutination is, for example, an index indicating the hardness of incineration ash. The predetermined value is, for example, a degree of agglutination that can suppress the occurrence of blockage due to the generation of clinker in the incinerator 1, etc. The third correspondence information is, for example, information stored in advance in the information storage area 130. Specifically, the third correspondence information is, for example, an approximate straight line (hereinafter also referred to as third approximate line) that indicates the correspondence relationship between the incineration temperature of sludge in the incinerator 1 and a threshold value for an evaluation index at which the degree of agglutination of incineration ash becomes equal to or less than a predetermined value. A specific example of step S3 will be described below.

[0084] [Specific example of step S3 (2)] FIG. 5 is a diagram illustrating a specific example of step S3. Specifically, FIG. 5 is a graph illustrating a specific example of the third approximate line LN3 for the sludge incineration temperature. More specifically, the third approximate line LN3 is an approximate line for the correlation between the temperature determined by a conglutination test and at which it is determined that blockage due to clinker generation can be avoided (for example, the temperature when the conglutination degree is 0.2 or less) and the evaluation index at the time of the determination. The horizontal axis of the graph shown in FIG. 5 corresponds to the evaluation index (threshold value of the evaluation index). The vertical axis of the graph shown in FIG. 5 corresponds to the sludge incineration temperature in the incinerator 1. Below, we will explain a case where both the suppression of blockage in the incinerator 1, the line L1, etc. and the desulfurization rate of the incineration ash to be equal to or higher than the first target value are achieved. The following explanation will be made with reference to the first approximate line LN1 and the second approximate line LN2 described in FIG. 4 as needed.

[0085] The third approximate line LN3 shown in Fig. 5 indicates that the threshold value of the evaluation index is 0.7 when the incineration temperature is 920°C. The first approximate line LN1 shown in Fig. 4 indicates that the threshold value of the evaluation index is 1.3 when the desulfurization rate is 0.6.

[0086] Therefore, for example, if the sludge incineration temperature specified by the operator is 920°C and the desulfurization rate is 0.6 or higher, the control device 10 specifies 0.7, which is the smaller of 1.3 and 0.7. In this case, the control device 10 specifies, for example, the amount of calcium to be input into the incinerator 1 so that the evaluation index is 0.7 or lower.

[0087] As a result, the incineration system 100 in this modified example can reduce the amount of calcium (chemical) added to the sludge in the incinerator 1 while achieving at least one of, for example, suppressing the occurrence of blockages in the incinerator 1, line L1, etc., and achieving a desulfurization rate in the incineration ash equal to or greater than a first target value.

[0088] Specifically, the incineration system 100 in this modified example is capable of suppressing the occurrence of blockages in the incinerator 1, line L1, etc., and achieving a desulfurization rate in the incineration ash equal to or greater than a first target value, while also reducing the amount of calcium (chemical) added to the sludge in the incinerator 1.

[0089] In other words, the incineration system 100 in this modified example is capable of reducing the amount of calcium added to the sludge in the incinerator 1 while achieving conditions different from those in the incineration system 100 in the first embodiment, for example.

[0090] The second approximate straight line LN2 shown in FIG. 4 indicates that, for example, when the citrate-soluble phosphorus ratio is "0.9", the threshold value of the evaluation index is "0.8".

[0091] Therefore, for example, if the sludge incineration temperature specified by the operator is 920°C, the desulfurization rate is 0.6 or more, and the citrate-soluble phosphorus rate is 0.9 or more, the control device 10 may specify 0.7, which is the smallest value among 1.3, 0.7, and 0.8. In this case, the control device 10 may specify, for example, the amount of calcium to be input into the incinerator 1 such that the evaluation index is 0.7 or less.

[0092] As a result, the incineration system 100 in this modified example can achieve, for example, suppressing the occurrence of blockages in the incinerator 1, line L1, etc., increasing the desulfurization rate in the incineration ash to a first target value or higher, and increasing the citrate-soluble phosphorus rate in the incineration ash to a second target value or higher, while reducing the amount of calcium (chemical) added to the sludge in the incinerator 1.

[0093] In other words, the incineration system 100 in this modified example makes it possible to suppress the amount of calcium added to the sludge in the incinerator 1 while simultaneously achieving a plurality of mutually different conditions, for example.

[0094] [Modification (2) of the index calculation process in the first embodiment] Next, another modified example (hereinafter also referred to as a second modified example) of the index calculation process in the first embodiment will be described. The second modified example will be described below with reference to FIGS.

[0095] In the index calculation process of the first embodiment, a case has been described in which, for example, in step S2 of Fig. 3, the evaluation index is calculated by substituting the first value, second value, third value, and fourth value acquired in step S1 of Fig. 3 into the above formula 1 or 6. In contrast, in the index calculation process of this modified example, in step S2 of Fig. 3, the evaluation index is calculated by substituting, for example, the first value, second value, third value, and fourth value acquired in step S1 of Fig. 1 into the following formula 7. That is, in the index calculation process of this modified example, the evaluation index is calculated by using, for example, the following formula 7, which is a modified version of the above formula 1, instead of the above formula 1 or 6.

[0096]

number

[0097] Specifically, in Equation 7, for example, the number of moles of iron (Fe2O3) in Equation 1 is multiplied by the ratio (hereinafter also referred to as the first ratio) of the number of moles of iron (Fe2O3) to the sum of the number of moles of iron (Fe2O3), the number of moles of aluminum (Al2O3), and the number of moles of calcium (CaO). Furthermore, in Equation 7, for example, the number of moles of aluminum (Al2O3) in Equation 1 is multiplied by the ratio (hereinafter also referred to as the second ratio) of the number of moles of aluminum (Al2O3) to the sum of the number of moles of iron (Fe2O3), the number of moles of aluminum (Al2O3), and the number of moles of calcium (CaO).

[0098] Then, in step S2 of FIG. 3, the control device 10 calculates the evaluation index by, for example, substituting the number of moles of phosphorus (P2O5) (first value) obtained in step S1 for [P2O5] / M(P2O5), substituting the number of moles of iron (Fe2O3) and the number of moles of aluminum (Al2O3) (second values) obtained in step S1 for [Fe2O3] / M(Fe2O3) and [Al2O3] / M(Al2O3), substituting the number of moles of sulfur (third value) obtained in step S1 for [total sulfur] / M(sulfur), and substituting the number of moles of calcium (CaO) (fourth value) obtained in step S1 for [CaO] / M(CaO).

[0099] That is, when calcium (chemical) is added to the sludge in the incinerator 1, the amount of metal salts (hereinafter simply referred to as metal salts) that can bind with phosphorus increases in the incinerator 1. The metal salts are, for example, iron, aluminum, or calcium. Therefore, in this case, for example, the amount of metal salts present in the incinerator 1 may become greater than the amount of metal salts that can bind with phosphorus, and a competitive reaction (hereinafter simply referred to as competitive reaction) may occur in which the metal salts compete for phosphorus.

[0100] Furthermore, each metal salt that reacts with phosphorus in the competitive reaction is determined according to the concentrations of various metal salts such as iron, aluminum, and calcium in the incinerator 1 (the frequency of collisions between phosphorus and each metal salt).

[0101] Therefore, in the index calculation process in this modified example, in step S2 of Figure 3, for example, the evaluation index is calculated using equation 7, in which the product of the number of moles of iron and the first ratio (i.e., the abundance ratio of iron to the total amount of iron, aluminum, and calcium) is used instead of the number of moles of iron, and the product of the number of moles of aluminum and the second ratio (i.e., the abundance ratio of aluminum to the total amount of iron, aluminum, and calcium) is used instead of the number of moles of aluminum.

[0102] Thereafter, in step S3 of FIG. 3, the control device 10 calculates the amount of calcium (chemical) to be fed into the incinerator 1 by using the evaluation index calculated by, for example, Equation 7.

[0103] Specifically, the third approximate line LN3 shown in Fig. 5 indicates that the threshold value of the evaluation index is 0.7 when the incineration temperature is 920°C. The first approximate line LN1 shown in Fig. 4 indicates that the threshold value of the evaluation index is 1.3 when the desulfurization rate is 0.6.

[0104] Therefore, for example, if the sludge incineration temperature specified by the operator is 920°C and the desulfurization rate is 0.6 or higher, the control device 10 specifies 0.7, which is the smaller of 1.3 and 0.7, as in the first embodiment. Then, in this case, the control device 10 specifies the amount of calcium to be input into the incinerator 1 such that the evaluation index calculated using Equation 7 is 0.7 or lower, as in the first embodiment.

[0105] As a result, in the index calculation process of this modified example, it is possible to calculate the evaluation index by using, for example, equation (Equation 7) that reflects the amount of each metal that reacts with phosphorus in a competitive reaction. Therefore, in the index calculation process of this modified example, it is possible to more accurately calculate, for example, the amount of calcium (chemical) that needs to be added to the sludge in the incinerator 1.

[0106] In the above formula 7, for example, the product of the number of moles of iron and the first ratio is used as the second term in the parentheses of the numerator, and the product of the number of moles of aluminum and the second ratio is used as the third term in the parentheses of the numerator, but this is not limiting. Specifically, in the above formula 7, for example, instead of the second and third terms in the parentheses of the numerator, a term consisting of the product of the number of moles of a predetermined metal (a metal including at least one of iron and aluminum) and the ratio of the number of moles of the predetermined metal to the sum of the number of moles of the predetermined metal and the number of moles of calcium may be used as the second term in the parentheses of the numerator.

[0107] In this way, the incineration system 100 in this modified example calculates a value (hereinafter also referred to as a ninth value) by, for example, adding the second value and the fourth value. That is, the ninth value is a value calculated by, for example, substituting the number of moles of iron (Fe2O3) and the number of moles of aluminum (Al2O3) (second values) obtained in step S1 for [Fe2O3] / M(Fe2O3) and [Al2O3] / M(Al2O3) in the following formula 8 (part of the above formula 7), and substituting the number of moles of calcium (CaO) (fourth value) obtained in step S1 for [CaO] / M(CaO) in the following formula 8.

[0108]

number

[0109] Then, the incineration system 100 in this modified example calculates a value (hereinafter also referred to as the tenth value) by, for example, multiplying the ratio of the second value to the ninth value by the second value. That is, the tenth value is a value calculated, for example, by substituting the number of moles of iron (Fe2O3) and the number of moles of aluminum (Al2O3) (second values) obtained in step S1 into [Fe2O3] / M(Fe2O3) and [Al2O3] / M(Al2O3) in the following formula 9 (part of the above formula 7), and substituting the number of moles of calcium (CaO) (fourth value) obtained in step S1 into [CaO] / M(CaO) in the following formula 9. Furthermore, the tenth value is a value calculated, for example, by substituting the number of moles of iron (Fe2O3) and the number of moles of aluminum (Al2O3) (second values) obtained in step S1 into [Fe2O3] / M(Fe2O3) and [Al2O3] / M(Al2O3), respectively, in the following formula 10 (part of the above formula 7), and substituting the number of moles of calcium (CaO) (fourth value) obtained in step S1 into [CaO] / M(CaO) in the following formula 10:

[0110]

number

[0111]

number

[0112] Furthermore, the incineration system 100 in this modified example calculates a value (hereinafter also referred to as the eleventh value) by, for example, subtracting the tenth value from the first value. That is, the eleventh value is a value calculated, for example, by substituting the number of moles of phosphorus (P2O5) (first value) obtained in step S1 for [P2O5] / M(P2O5) in the following formula 11 (part of the above formula 7), substituting the number of moles of iron (Fe2O3) and the number of moles of aluminum (Al2O3) (second values) obtained in step S1 for [Fe2O3] / M(Fe2O3) and [Al2O3] / M(Al2O3), respectively, in the following formula 11, and substituting the number of moles of calcium (CaO) (fourth value) obtained in step S1 for [CaO] / M(CaO) in the following formula 11.

[0113]

number

[0114] Thereafter, the incineration system 100 in this modified example calculates a value (hereinafter also referred to as a twelfth value) by adding the eleventh value and the third value, for example. That is, the twelfth value is calculated, for example, by substituting the number of moles of phosphorus (P2O5) obtained in step S1 (first value) for [P2O5] / M(P2O5) in the following formula 12 (a part of the above formula 7), substituting the number of moles of iron (Fe2O3) and the number of moles of aluminum (Al2O3) (second values) obtained in step S1 for [Fe2O3] / M(Fe2O3) and [Al2O3] / M(Al2O3), respectively, substituting the number of moles of sulfur obtained in step S1 (third value) for [total sulfur] / M(sulfur) in the following formula 12, and substituting the number of moles of calcium (CaO) obtained in step S1 (fourth value) for [CaO] / M(CaO) in the following formula 12.

[0115] Then, the incineration system 100 in this modified example calculates, for example, the ratio of the twelfth value to the fourth value as the evaluation index. Specifically, the incineration system 100 in this modified example calculates the evaluation index from the number of moles of calcium (CaO) (fourth value) obtained in step S1 and the twelfth value calculated by the above formula 12, for example, by using the above formula 7.

[0116] As a result, the incineration system 100 in this modification can calculate the evaluation index by using an equation that reflects the amount of each metal that reacts with phosphorus in a competitive reaction, for example. Therefore, the incineration system 100 in this modification can more accurately calculate, for example, the amount of calcium (chemical) that needs to be added to the sludge in the incinerator 1. [Explanation of symbols]

[0117] 1: Incinerator 1a: Fluidized bed 2: Storage tank 3: Dust collector 10: Control device 100: Incineration system 101:CPU 102:Memory 103: Communication device 104: Storage medium 105: Bus B1: Fan L1: Line L2: Line L3: Line L11: Line L21: Line L31: Line LN1: Approximate straight line LN2: Approximate straight line LN3: Approximate line P1: Pump

Claims

1. Obtain a first value relating to the amount of phosphorus contained in the material to be incinerated, a second value relating to the amount of said phosphorus bonded to a predetermined metal, a third value relating to the amount of sulfur contained in said material to be incinerated, and a fourth value relating to the amount of calcium to be added to said material to be incinerated; A method for calculating a chemical addition index, which calculates an evaluation index for the amount of calcium to be added to the material to be incinerated based on the acquired first value, second value, third value, and fourth value.

2. 2. The method for calculating a chemical addition index according to claim 1, wherein the amount of calcium to be added to the material to be incinerated is controlled based on the calculated evaluation index.

3. In the step of calculating the evaluation index, calculating a fifth value by subtracting the second value from the first value; calculating a sixth value by adding the fifth value and the third value; The method for calculating a drug addition index according to claim 1 , wherein the evaluation index is calculated as a ratio of the sixth value to the fourth value.

4. In the step of calculating the evaluation index, calculating a seventh value by subtracting the third value from the fourth value; calculating an eighth value by adding the second value and the seventh value; The drug addition index calculation method according to claim 1 , wherein the evaluation index is calculated as a ratio of the eighth value to the first value.

5. In the step of calculating the evaluation index, calculating a ninth value by adding the second value and the fourth value; calculating a tenth value by multiplying the ratio of the second value to the ninth value by the second value; calculating an eleventh value by subtracting the tenth value from the first value; calculating a twelfth value by adding the eleventh value and the third value; The drug addition index calculation method according to claim 1 , wherein the evaluation index is calculated as a ratio of the twelfth value to the fourth value.

Images