Sludge Incineration Method and Mixed Sludge Incineration System

Abstract

To provide a sludge incineration method for incinerating at a minimum running cost, mixed sludge K where multiple pieces of sludge having different features, are mixed, in an incinerator.SOLUTION: There is provided a sludge mixing putting method for converting mixed sludge K where multiple pieces of sludge having different features to be combusted in an incinerator 30, are mixed, into mixed sludge which does not require supplement fuel and cooling water or in which use amounts of them can be reduced, and then putting the mixed sludge into the incinerator, in which the method is configured to; determine a flow rate and a moisture content of each sludge to be mixed to the mixed sludge to be supplied to the incinerator, from a flow meter 5 and a moisture content meter 6, then determine a moisture content (per flow rate unit time) by calculating by a calculator, the determined flow rate value and the moisture content value, then determine a mixing ratio of pieces of sludge to be mixed on the basis of the moisture content. Then, the mixed sludge is supplied to the incinerator for combusting, and on the basis of an inside of furnace temperature in the incinerator during combustion of the mixed sludge, the mixing ratio of the sludge to be transferred to a mixing machine 20 is changed and the sludge is supplied to the incinerator at the changed mixing ratio, for minimizing, costs of cooling water and supplement fuel required for incineration of the sludge.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for controlling the ratio of sludges having different properties (moisture content and calorific value) and a sludge incineration system when mixing sludges having different properties (such as moisture content) generated in the sewage treatment process of a sewage treatment plant and incinerating the mixture in an incinerator. [Background Art]

[0002] Solids precipitated and separated in the sewage treatment process are concentrated and dehydrated to generate dewatered sludge. Dewatered sludge is normally incinerated, and there are cases where dewatered sludge is incinerated as it is, and cases where the volume is reduced by anaerobic digestion before incineration. The latter utilizes methane fermentation reaction, which leads to effective utilization of energy resources in the form of methane gas. However, after digestion, the affinity between decomposition products of solids in sludge and water increases, resulting in sludge with high moisture content that is difficult to dewater. In large cities and the like, there are facilities that collect sludge from each sewage treatment plant via vehicles or transfer pipes, and sludge with high moisture content such as digested sludge after digestion reaction is transported in a mixed state with sludge with relatively low moisture content that does not contain digested sludge. Therefore, in the incinerator of a centralized facility, sludges with different moisture contents are stacked in layers in a hopper that supplies sludge for incineration. In addition, the incinerator is provided with a plurality of sludge supply pipes. Depending on the system of the sludge supply pipe, sludge with high moisture content and low calorific value that is difficult to burn, or sludge with low moisture content and high calorific value may be supplied to the supply hopper. As sludges of these properties mix with the passage of time, sludges with different moisture contents and calorific values are stacked in layers in the supply hopper. Even if it is not a centralized facility, in a sewage treatment plant equipped with an incinerator, there are raw sludge with high solids concentration in the primary sedimentation tank (low moisture content and high calorific value) and excess sludge derived from microorganisms in the final sedimentation tank (high moisture content and low calorific value). In addition, there may be cases where there is sludge that has undergone a sludge digestion process and sludge that has not undergone a sludge digestion process, which can lead to a situation where sludges with different moisture contents are stacked in layers in the supply hopper for incineration. [Summary of the Invention] [Problem to be Solved by the Invention]

[0003] When sludge with varying moisture content is layered in the supply hopper during incineration, easily combustible and difficult-to-combust sludge are supplied to the incinerator, causing fluctuations in the combustion temperature. While combustion temperature is controlled by adjusting the supply amount of auxiliary fuels such as heavy oil or city gas, or by injecting cooling water into the furnace, these adjustments must be made precisely in accordance with the fluctuations in combustion temperature. When the fluctuations in combustion temperature become large, it can lead to the wasteful consumption of auxiliary fuels by injecting cooling water without effectively utilizing the calorific value of the sludge, or to the wasteful consumption of auxiliary fuels by operating the incinerator at high combustion temperatures.

[0004] The present invention has been made in view of the above problems, and its purpose is to minimize the consumption of auxiliary fuel and cooling water by mixing sludge of different properties in a mixer, feeding the mixed sludge (hereinafter referred to as mixed sludge K) into an incinerator, and adjusting the amount of sludge of different properties transferred to the mixer based on the furnace temperature inside the incinerator. [Means for solving the problem]

[0005] To achieve the above objective, the inventors of this invention solved the above problem by the following means. [1] A sludge incineration method in which mixed sludge K, which is a mixture of sludges with multiple properties, is converted into a mixed sludge that can reduce or eliminate the need for auxiliary fuel and cooling water, and is then fed into an incinerator for incineration, A furnace temperature control step involves supplying the mixed sludge to an incinerator and burning it, and controlling the furnace temperature by adjusting the supply amounts of auxiliary fuel and cooling water based on the furnace temperature inside the incinerator during the combustion of the mixed sludge. The flow rate and moisture content of each sludge are determined using a flow meter and a moisture content meter, and the obtained flow rate and moisture content values ​​are calculated using a calculator to determine the moisture content (per unit time of flow rate). A sludge mixing ratio control step in which the mixing ratio of sludge to be mixed is determined based on the moisture content, and the sludge is mixed based on the said mixing ratio, A mixing flow rate control step that adjusts the mixing ratio of the mixed sludge supplied to the incinerator based on the sludge mixing ratio control step, A sludge incineration method characterized by including the following.

[0006] [2] Multiple storage hoppers for storing sludge of multiple properties different from each other, multiple transfer pumps for transferring the sludge to a mixer (20), a flow meter for measuring the flow rate of the sludge and a moisture content meter for measuring the moisture content of the sludge, installed in the middle of the piping connected between the transfer pumps and the mixer (20), at least one supply hopper (21) for storing the mixed sludge K obtained by mixing the sludge in the mixer (20) and supplying it to the incinerator (30), and a transfer pump (23) installed in the supply hopper (21), An incinerator (30) is provided with an in-furnace thermometer (31), a cooling water supply device (32) that supplies cooling water into the incinerator (30), and a cooling water flow meter (34) and a cooling water control valve (35) are provided in the middle of the piping (33) that connects the cooling water supply device (32) and the incinerator (30), An auxiliary fuel supply device (42) that supplies auxiliary fuel into the incinerator (30), and an auxiliary fuel flow meter (44) and an auxiliary fuel control valve (45) installed in the middle of the piping (43) connected to the auxiliary fuel supply device (42) and the incinerator (30), A calculation unit (50) calculates the amount of water by calculating the measured values ​​of a flow meter and a moisture content meter, which are installed in the middle of the piping connected to the mixer (20), and the water content of the sludge. Based on the amount of moisture from the arithmetic unit (50) The sludge is then transferred to the mixer (20). The aforementioned transfer A sludge incineration system characterized by comprising a control device (60) that adjusts the supply amount with a pump and adjusts the supply amounts of cooling water and auxiliary fuel with a cooling water control valve (35) and an auxiliary fuel control valve (45) based on the furnace temperature measured by the furnace thermometer (31).

[0007] [3] Multiple storage hoppers for storing sludge of different properties, multiple transfer pumps for transferring sludge to a mixer (20), and a flow meter for measuring the flow rate of sludge and a moisture content meter for measuring the moisture content of sludge, which are installed in the middle of the piping connected to the transfer pumps and the mixer (20). An incinerator (30) is provided with an in-furnace thermometer (31), a cooling water supply device (32) that supplies cooling water into the incinerator (30), and a cooling water flow meter (34) and a cooling water control valve (35) are provided in the middle of the piping (33) that connects the cooling water supply device (32) and the incinerator (30), An auxiliary fuel supply device (42) that supplies auxiliary fuel into the incinerator (30), and an auxiliary fuel flow meter (44) and an auxiliary fuel control valve (45) installed in the middle of the piping (43) connected to the auxiliary fuel supply device (42) and the incinerator (30), A calculation unit (50) calculates the amount of water by calculating the measured values ​​of a flow meter and a moisture content meter, which are installed in the middle of the piping connected to the mixer (20), and the water content of the sludge. Based on the amount of moisture from the arithmetic unit (50) The sludge is then transferred to the mixer (20). The aforementioned transfer A sludge incineration system characterized by comprising a control device (60) that adjusts the supply amount with a pump and adjusts the supply amounts of cooling water and auxiliary fuel with a cooling water control valve (35) and an auxiliary fuel control valve (45) based on the furnace temperature measured by the furnace thermometer (31). [Effects of the Invention]

[0008] According to the present invention, the mixing ratio of the mixed sludge can be appropriately controlled, so that the consumption of auxiliary fuel and cooling water can be minimized and sludge with different properties can be burned. [Brief explanation of the drawing]

[0009] [Figure 1] Schematic diagram showing a first embodiment of the present invention [Figure 2] Flowchart of furnace temperature control in the first embodiment [Figure 3] Flowchart for controlling the sludge mixing ratio in the first embodiment [Figure 4] Flowchart for controlling the sludge mixing ratio in the first embodiment [Figure 5] Schematic diagram showing a second embodiment of the present invention [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present invention will be exemplarily described in detail with reference to the drawings.

Embodiment

[0011] Figure 1 is a schematic configuration diagram showing a first embodiment of the present invention. The present embodiment 1 includes a first storage hopper 1 that stores sludge A, and discharges the sludge A in the first storage hopper 1 ru a sludge discharger 2, a transfer pump 3 that supplies sludge A, a second storage hopper 11 that stores sludge B having different properties from sludge A, and discharges sludge B in the second storage hopper 11 ru a sludge discharger 12, and a transfer pump 13 that supplies sludge B, a mixer 20 that mixes sludge A and sludge B supplied by the transfer pump 3 and the transfer pump 13, a supply hopper 21 that stores mixed sludge K supplied from the mixer 20 and supplies the mixed sludge K to an incinerator, and discharges the mixed sludge K in the supply hopper 21 ru a sludge discharger 22, and a transfer pump 23 that supplies mixed sludge K. It should be noted that, although the present embodiment is described as having separate supply paths for sludges A and B with different properties, it should be noted that in practice, the properties of sludge, including moisture content and calorific value, change over time in each supply path, and the properties of sludge supplied through each supply path do not necessarily differ. A flow meter 5 for measuring the flow rate of sludge and a moisture content meter 6 for measuring the moisture content of sludge are provided in the middle of the pipe 4 connected to the transfer pump 3 and the mixer 20, and a flow meter 15 for measuring the flow rate of sludge and a moisture content meter 16 for measuring the moisture content of sludge are provided in the middle of the pipe 14 connected to the transfer pump 13 and the mixer 20. The above constitutes a sludge flow rate control system that supplies mixed sludge K to the incinerator 30.

[0012] The incinerator 30 is provided with a furnace thermometer 31 for measuring the temperature inside the furnace. Further, a cooling water supply system that cools the interior of the furnace according to the furnace temperature at which sludge is combusted in the furnace, and an auxiliary fuel supply system that adjusts the furnace temperature are provided. In the cooling water supply system, a cooling water supply device 32 configured to supply cooling water into an incinerator 30, and a cooling water flow meter 34 and a cooling water regulating valve 35 are provided in the middle of a pipe 33 connected between the cooling water supply device 32 and the incinerator 30. In the auxiliary fuel supply system, an auxiliary fuel supply device 42 configured to supply auxiliary fuel into an incinerator 30, and an auxiliary fuel flow meter 44 and an auxiliary fuel regulating valve 45 are provided in the middle of a pipe 43 connected between the auxiliary fuel supply device 42 and the incinerator 30.

[0013] In the schematic configuration diagram showing the first embodiment of the present invention, a control device 60 and a calculator 50 are provided. The calculator 50 receives the flow value and moisture content value of sludge A (sludge B) measured by the flow meter 5 (15) and the moisture content meter 6 (16), performs calculation, and obtains the moisture content (per unit flow time) of sludge A (sludge B) as a calculated value. The control device 60 is, for example, a PLC (Programmable Logic Controller), and operates based on a control program executed by the PLC. The control device 60 receives signals from various in-furnace sensors (an in-furnace thermometer, the cooling water flow meter, and the auxiliary fuel flow meter) and the calculator 50, and sends control signals corresponding to the received signals to various devices (the cooling water regulating valve, the auxiliary fuel regulating valve, and inverter-driven motors 7 and 17 (hereinafter referred to as motors)) through a built-in control program to control the various devices. In the figure, dashed lines with arrows indicate signal lines through which the control device 60 sends control signals to the cooling water regulating valve 35, the auxiliary fuel regulating valve 45, and the motors 7 and 17. For example, the control device 60 receives an in-furnace temperature value from an in-furnace thermometer 31, sends an opening command signal to the cooling water regulating valve 35 based on the in-furnace temperature value, and regulates the opening degree of the cooling water regulating valve 35. Alternatively, the control device 60 receives a temperature value from the in-furnace thermometer 31, sends an opening command signal to the auxiliary fuel regulating valve 45 based on the in-furnace temperature value, and regulates the opening degree of the auxiliary fuel regulating valve 45.

[0014] A method for supplying mixed sludge K to an incinerator according to the first embodiment will be described. The dewatered sludge A generated from the sewage treatment process at the sewage treatment plant is stored in the first storage hopper 1, and the sludge A is transferred to the mixer 20 by the sludge discharger 2 and the transfer pump 3. At this time, the flow rate and moisture content of the sludge A are measured by a flow meter 5 and a moisture content meter 6 installed in the piping 4 connected to the transfer pump 3 and the mixer 20, and these measured values ​​are sent to a calculation device 50, which then calculates the moisture content of the sludge A. Meanwhile, the dewatered sludge B generated from the sewage treatment process at the sewage treatment plant is stored in the second storage hopper 11, and the sludge B is transferred to the mixer 20 by the sludge discharger 12 and the transfer pump 13. At this time, the flow rate and moisture content of the sludge B are measured by a flow meter 15 and a moisture content meter 16 installed in the piping 14 connected to the transfer pump 13 and the mixer 20, and these measured values ​​are sent to a calculation device 50, which then calculates the moisture content of the sludge B. At this time, the flow rate and moisture content of sludge A and sludge B are measured using the flow meter (5, 15) and moisture content meter (6, 16), and these measured values ​​are output to the calculator 50. The calculator 50 performs a calculation (moisture content value × flow rate value) and transfers the sludge A and sludge B in a ratio that reduces the amount of auxiliary fuel and cooling water used to create mixed sludge to the mixer 20. The mixer 20 then mixes the sludge A and sludge B to homogenize the mixed sludge K. Then, the mixed sludge K is transferred from the mixer 20 to the supply hopper 21 for storage, and from the supply hopper 21 it is supplied to the incinerator 30.

[0015] To explain the method of transferring sludge A and sludge B in a ratio that reduces the use of auxiliary fuel and cooling water to the mixer 20, and then mixing sludge A and sludge B in the mixer 20 to homogenize the mixed sludge K, we will first explain the control of the furnace temperature using Figure 2, a control flowchart that controls the furnace temperature due to the incineration of the mixed sludge K supplied to the incinerator 30. Step 1 (S1) Determine if the furnace temperature (Ti) is lower than the set temperature value (TiSV). Step 2 (S2) If the furnace temperature (Ti) is lower than the set temperature value (TiSV), the decision will be made to increase Ti. Step 3 (S3) To increase the furnace temperature (Ti), the opening of the auxiliary fuel control valve 45 is increased to increase the amount of auxiliary fuel supplied to the incinerator. At the same time, the opening of the cooling water control valve 35 is decreased to reduce the amount of cooling water injected into the incinerator. Step 4 (S4) If the furnace temperature (Ti) is higher than the set temperature value (TiSV), the decision will be made to lower Ti. Step 5 (S5) To lower the furnace temperature (Ti), the opening of the auxiliary fuel control valve 45 is reduced to decrease the amount of auxiliary fuel supplied to the incinerator. At the same time, the opening of the cooling water control valve 35 is increased to increase the amount of cooling water injected into the incinerator. The above describes the basic control method of the present invention, which involves adjusting the amount of cooling water and the amount of auxiliary fuel to control the internal temperature of the furnace.

[0016] Next, we will explain the control of the flow rate (supply amount) of sludge A or sludge B that constitutes the mixed sludge K supplied to the incinerator 30, using Figure 3, which is a sludge mixing ratio control flowchart that controls the sludge mixing ratio of sludge A and sludge B when the furnace temperature is controlled by the use of auxiliary fuel and cooling water while the mixed sludge K supplied to the incinerator 30 is being incinerated. Step 1 (S1) The measurement value of the auxiliary fuel supply amount Ff is used to determine whether auxiliary fuel is being supplied within the incinerator. Step 2 (S2) If auxiliary fuel is used in the incinerator, the calculator 50 determines whether the moisture content of sludge A (flow rate per unit time) (measured value Fa from the flow meter 5 × measured value Wa from the moisture content meter 6), calculated by the calculator 50, is greater than the moisture content of sludge B (flow rate per unit time) (measured value Fb from the flow meter 15 × measured value Wb from the moisture content meter 16), also calculated by the calculator 50. Step 3 (S3) If the moisture content of sludge A is high in S2, reduce the set flow rate of sludge A and proceed to *1A. Perform S6 simultaneously. Step 4 (S4) If no auxiliary fuel is being used in the incinerator, the cooling water supply rate Fc is measured to determine whether cooling water is being used. Step 5 (S5) If cooling water is used in the incinerator, the calculator 50 determines whether the moisture content of sludge A (Fa × Wa) is less than the moisture content of sludge B (Fb × Wb). Step 6 (S6) If the moisture content of sludge B is high in S5, increase the set value for the flow rate of sludge B and proceed to *1B. Perform S3 simultaneously. Step 7 (S7) In S2, if the moisture content of sludge A is low, increase the set value for the flow rate of sludge A and proceed to *1A. Perform S8 simultaneously. Step 8 (S8) In S5, if the moisture content of sludge B is low, reduce the set value of the flow rate of sludge B and proceed to *1B. Perform S7 simultaneously. Step 9 (S9) If cooling water is not being used in the incinerator, the control system will terminate.

[0017] The above describes how the furnace temperature is controlled by controlling the supply amounts of sludge A and sludge B to the furnace based on the usage of cooling water and auxiliary fuel inside the furnace. The basic idea of ​​the present invention is as follows. 1) Compare the calculated values ​​of "Moisture content meter A measurement × Flow meter A measurement (product)" and "Moisture content meter B measurement × Flow meter B measurement (product)" to determine which system, A or B, has a higher moisture content per hour. [1] If cooling water is used in the incinerator The amount of sludge is increased in the system with the higher value (higher moisture content) of the product of "moisture content meter reading × flow meter reading," and decreased in the system with the lower value (lower moisture content). [2] When using auxiliary fuel in an incinerator The amount of sludge is increased in the system with the smaller value (low moisture content) of the product of "moisture content meter reading × flow meter reading," and decreased in the system with the larger value (high moisture content). The amount by which the mixing ratio is changed at this time is determined by the usage of cooling water or auxiliary fuel.

[0018] Next, using Figure 4, which is a control flowchart of the sludge flow rates (1A, 1B) obtained by controlling the sludge mixing ratio of sludge A and sludge B, we will explain the control of the supply amounts (flow rates) of sludge A (Fa) and sludge B (Fb). Step 1 (S1) Following the sludge mixing ratio control (*1A), the increased or decreased sludge flow rate setpoint FaSV value is input. Step 2 (S2) Determine if the flow rate Fa of sludge A is less than the set flow rate value FaSV. Step 3 (S3) If the flow rate Fa of sludge A is less than the set flow rate FaSV, the rotation speed of the motor 7 of the transfer pump 3 is increased to increase the sludge flow rate Fa. Step 4 (S4) If the flow rate Fa of sludge A is greater than the set flow rate FaSV, the rotation speed of the motor 7 of the transfer pump 3 is reduced to decrease the sludge flow rate Fa. Step 5 (S5) Following the sludge mixing ratio control (*1B), the increased or decreased sludge flow rate set value FaSV is input. Step 6 (S6) Determine if the flow rate Fb of sludge B is less than the set flow rate FbSV. Step 7 (S7) If the flow rate Fb of sludge B is less than the set flow rate FbSV, the rotational speed of the motor 17 of the transfer pump 13 is increased to increase the sludge flow rate Fb. Step 8 (S8) If the flow rate Fb of sludge B is greater than the set flow rate FbSV, the rotational speed of the motor 17 of the transfer pump 13 is reduced to decrease the sludge flow rate Fb.

[0019] Based on the above controls, the method for incinerating sludge (mixed sludge K) will be explained. As described above, sludge A and sludge B are transferred to the mixer 20 at a mixing ratio of sludge A and sludge B set based on their respective water content (a ratio of sludge A to sludge B that results in a mixed sludge that requires less auxiliary fuel and cooling water), and the mixed sludge K is transferred to the supply hopper 21 and stored. The mixed sludge K stored from the supply hopper 21 is supplied to the incinerator and incinerated. Here, the furnace temperature is measured by a furnace thermometer 31 in the incinerator where the mixed sludge K is being burned, and the furnace is controlled to maintain the set furnace temperature by injecting cooling water into the furnace as needed, or by supplying auxiliary fuel into the furnace to adjust the temperature. In conjunction with the above temperature control, the system maintains the set internal temperature by minimizing the use of auxiliary fuel and cooling water, based on the cooling water and auxiliary fuel supplied to the reactor. This is achieved by supplying more sludge with a high moisture content when the internal temperature is high, and more sludge with a low moisture content when the internal temperature is low. [Table 1]

[0020] Table 1 shows an example of the daily cost when sludge A, which has a high proportion of wastewater treatment that does not undergo the digestion process, is incinerated first, followed by sludge B, which has a high proportion of wastewater treatment that does undergo the digestion process, or vice versa, and when sludge A and sludge B are supplied to the incinerator and incinerated simultaneously. As an example, this is a cost comparison for incinerating a total of 50 tons of sludge, consisting of 30 tons of sludge A and 20 tons of sludge B, per day. This explains the cost required to incinerate 30 tons of sludge A when sludge A and sludge B are incinerated sequentially. Since sludge A has not undergone the digestion process, the decomposition of organic matter by anaerobic digestion has not occurred, resulting in a high calorific value and requiring cooling water to raise the furnace temperature of the incinerator. The cost of cooling water when treated water from the sewage treatment plant is used is 71 yen. The cost of cooling water when tap water is used is 2,848 yen. The cost required to incinerate 20 tons of sludge B, including the cost of auxiliary fuel (city gas), is 71,506 yen. Thus, the cost required to incinerate a total of 50 tons of sludge A and sludge B separately is 71,577 yen if treated water is used as cooling water, and 74,354 yen if tap water is used as cooling water. In contrast, the cost required to incinerate 50 tons of mixed sludge (a mixture of sludge A and sludge B) is 6,632 yen, as both the amount of auxiliary fuel and cooling water used can be reduced (cooling water is not required), and the cost of auxiliary fuel (city gas) is 6,632 yen. As shown above, mixing sludge A and sludge B and incinerating the mixed sludge, taking into account the water content of each sludge, reduces the amount of cooling water and auxiliary fuel used compared to incinerating sludge A and sludge B separately, resulting in significantly lower costs. Although the above explanation illustrates the case where sludge A and sludge B are supplied to the incinerator, the present invention is not limited to this and can be applied to cases where there are multiple supply routes.

[0021] Figure 5 is a schematic diagram showing a second embodiment of the present invention. Using Figure 5, the second of implementation example Explain. In this embodiment, only the differences from the first embodiment will be described. The flow rate and water content of sludge A and sludge B, which are generated from the sewage treatment process at the sewage treatment plant and then dewatered, are measured and output to a calculator 50. The calculator 50 performs calculations (water content value × flow rate value) to transfer the sludge A and sludge B in a ratio that requires less auxiliary fuel and cooling water to the mixer 20, where the sludge A and sludge B are mixed to homogenize the mixed sludge K. Then, the mixed sludge K is supplied from the mixer 20 to the incinerator 30. Subsequently, basic control of the furnace temperature, control of the sludge mixing ratio, and control of the sludge flow rate determined by the sludge mixing ratio control are performed. This embodiment differs in that it does not have a supply hopper, and the mixed sludge K is supplied from the mixer 20 to the incinerator 30. In the first embodiment, the amount of water supplied to the incinerator can be adjusted not only by adjusting the supply amount of the transfer pumps 3 and 13, but also by adjusting the supply amount of the transfer pump 23. In the second embodiment, it would be ideal if the temperature fluctuations inside the furnace could be tolerated by adjusting only the supply amount of the transfer pumps 3 and 13, but the accuracy of the moisture content meter may change or the calorific value of the sludge may fluctuate due to the influence of measurement conditions such as the properties of the sludge, which can lead to fluctuations in the temperature inside the furnace. In that case, as in the first embodiment, only the amount that can be stored in the supply hopper 21 can be adjusted. transfer The supply amount can be adjusted by pump 23 according to fluctuations in the furnace temperature. Although the above explanation illustrates the case where sludge A and sludge B are supplied to the incinerator, the present invention is not limited to this and can be applied to cases where there are multiple supply routes.

[0022] Furthermore, the moisture content of sludge A and sludge B collected by the control device (60) can also be used to adjust the moisture content in the dewatering equipment in the pre-incineration process. By adjusting the dewatering capacity of the dewatering equipment according to the moisture content and adjusting the total moisture content within a predetermined range, it becomes possible to suppress fluctuations in the furnace temperature during incineration. [Explanation of Symbols]

[0023] 1: First storage hopper 11: Second storage hopper 2, 12, 22: Sludge discharger 3, 13, 23: Transfer pumps 4, 14: Piping 5, 15: Flowmeter 6, 16: Moisture content meter 20: Mixer 21: Supply hopper 30: Incinerator 31:Furnace thermometer 32: Cooling water supply device 33: Piping 34: Cooling water flow meter 35: Cooling water control valve 42:Auxiliary fuel supply device 43: Piping 44: Auxiliary fuel flow meter 45: Auxiliary fuel control valve 50: Arithmetic unit 60: Control device

Claims

1. A sludge incineration method in which mixed sludge K, which is a mixture of sludges with multiple properties, is converted into a mixed sludge that can reduce or eliminate the need for auxiliary fuel and cooling water, and then fed into an incinerator for incineration, A furnace temperature control step involves supplying the mixed sludge to an incinerator and burning it, and controlling the furnace temperature by adjusting the supply amounts of auxiliary fuel and cooling water based on the furnace temperature inside the incinerator during the combustion of the mixed sludge. The flow rate and moisture content of each sludge are determined using a flow meter and a moisture content meter, and the obtained flow rate and moisture content values ​​are calculated using a calculator to determine the moisture content (per unit time of flow rate). A sludge mixing ratio control step in which the mixing ratio of sludge to be mixed is determined based on the moisture content, and the sludge is mixed based on the said mixing ratio, A mixing flow rate control step that adjusts the mixing ratio of the mixed sludge supplied to the incinerator based on the sludge mixing ratio control step, A sludge incineration method characterized by including the following.

2. Multiple storage hoppers for storing sludge of multiple properties different from each other, multiple transfer pumps for transferring sludge to a mixer (20), a flow meter for measuring the flow rate of sludge and a moisture content meter for measuring the moisture content of sludge, installed in the middle of the piping connected between the transfer pumps and the mixer (20), at least one supply hopper (21) for storing the mixed sludge K obtained by mixing sludge in the mixer (20) and supplying it to the incinerator (30), and a transfer pump (23) installed in the supply hopper (21), An incinerator (30) is provided with an in-furnace thermometer (31), a cooling water supply device (32) that supplies cooling water into the incinerator (30), and a cooling water flow meter (34) and a cooling water control valve (35) are provided in the middle of the piping (33) that connects the cooling water supply device (32) and the incinerator (30), An auxiliary fuel supply device (42) that supplies auxiliary fuel into the incinerator (30), and an auxiliary fuel flow meter (44) and an auxiliary fuel control valve (45) installed in the middle of the piping (43) connected to the auxiliary fuel supply device (42) and the incinerator (30), A calculation unit (50) calculates the amount of water by calculating the measured values ​​of a flow meter for measuring the flow rate of sludge and a moisture content meter for measuring the moisture content of sludge, which are installed in the middle of the piping connected to the mixer (20), A sludge incineration system characterized by comprising a control device (60) that adjusts the supply amount of sludge to a mixer (20) using a transfer pump based on the amount of moisture from a calculator (50), and the supply amount of cooling water and auxiliary fuel using a cooling water control valve (35) and an auxiliary fuel control valve (45) based on the furnace temperature measured by a furnace thermometer (31).

3. Multiple storage hoppers for storing sludge of different properties, multiple transfer pumps for transferring sludge to a mixer (20), and a flow meter for measuring the flow rate of sludge and a moisture content meter for measuring the moisture content of sludge, which are installed in the middle of the piping connected to the transfer pumps and the mixer (20). An incinerator (30) is provided with an in-furnace thermometer (31), a cooling water supply device (32) that supplies cooling water into the incinerator (30), and a cooling water flow meter (34) and a cooling water control valve (35) are provided in the middle of the piping (33) that connects the cooling water supply device (32) and the incinerator (30), An auxiliary fuel supply device (42) that supplies auxiliary fuel into the incinerator (30), and an auxiliary fuel flow meter (44) and an auxiliary fuel control valve (45) installed in the middle of the piping (43) connected to the auxiliary fuel supply device (42) and the incinerator (30), A calculation unit (50) calculates the amount of water by calculating the measured values ​​of a flow meter for measuring the flow rate of sludge and a moisture content meter for measuring the moisture content of sludge, which are installed in the middle of the piping connected to the mixer (20), A sludge incineration system characterized by comprising a control device (60) that adjusts the supply amount of sludge to a mixer (20) using a transfer pump based on the amount of moisture from a calculator (50), and the supply amount of cooling water and auxiliary fuel using a cooling water control valve (35) and an auxiliary fuel control valve (45) based on the furnace temperature measured by a furnace thermometer (31).

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