Ash treatment system

Abstract

An ash treatment system (1) for treating ash discharged from an incinerator (A) comprises: an ash treatment device (3) that cools ash with water and transports the cooled ash; and a receiving-port hydrogen sensor (41G). The ash treatment device (3) includes a receiving port (311A) for receiving ash. The receiving-port hydrogen sensor (41G) can measure the hydrogen concentration in the receiving port (311A).

Description

Ash Handling System

[0001] The present invention relates to an ash handling system.

[0002] BACKGROUND ART Conventionally, as equipment for cooling incineration ash discharged from an incinerator, an ash extrusion device is known which cools the ash in a tank in which cooling water is stored and extrudes the cooled ash.

[0003] It is known that in such ash extrusion devices, hydrogen gas is produced by a reaction between the cooling water, which has become alkaline by cooling the incineration ash (the main component of which is alkaline), and the metal (aluminum) contained in the incineration ash.

[0004] For example, Patent Document 1 below discloses an explosion prevention device in an incineration ash cooling device equipped with a sealed tank having an ash inlet section and an ash outlet section, which introduces outside air into the top of the ash outlet section to discharge hydrogen gas from the tank.

[0005] Patent No. 3501626

[0006] In the explosion prevention device described in the above-mentioned Patent Document 1, when incineration ash from the incinerator adheres to and grows on the inner wall of the ash discharge pipe (chute), a condition called a "bridge" occurs, in which the inside of the ash discharge pipe is blocked. If the ash discharge pipe is blocked by a bridge, the occurrence of the bridge cannot be detected, and there is a possibility that hydrogen gas will accumulate near the ash input section over time.

[0007] If hydrogen gas accumulates near the ash injection point and then an attempt is made to remove the bridge, it becomes an extremely dangerous operation that could result in an explosion.

[0008] The present invention provides an ash handling system that can detect the occurrence of bridging near the receiving port at an early stage.

[0009] The present invention [1] includes an ash treatment system for treating ash discharged from an incinerator, the ash treatment system comprising an ash treatment device that cools the ash with water and transports the cooled ash, and a hydrogen sensor, the ash treatment device having an inlet for receiving the ash, and the hydrogen sensor capable of measuring the hydrogen concentration in the inlet.

[0010] With this configuration, if a bridge occurs near the receiving port, the hydrogen sensor can detect an increase in the hydrogen concentration inside the receiving port.

[0011] Therefore, the occurrence of a bridge near the receiving port can be detected early.

[0012] As a result, bridge elimination work can be carried out before the risk of explosion increases.

[0013] The present invention [2] includes the ash treatment system of [1] above, wherein the ash treatment system further comprises a chute that guides the ash discharged from the incinerator to the ash treatment device, the chute having one end connected to the incinerator and the other end connected to the receiving port of the ash treatment device, and a control device capable of receiving signals from the hydrogen sensor, and wherein the control device executes a warning process to warn of blockage of the chute when the hydrogen concentration detected by the hydrogen sensor exceeds a threshold value.

[0014] With this configuration, if the chute is blocked by a bridge near the receiving port, hydrogen gas generated within the ash treatment device may accumulate near the receiving port, causing the hydrogen concentration near the receiving port to increase.

[0015] Therefore, if the hydrogen concentration detected by the hydrogen sensor exceeds the threshold value, it is suspected that a bridge may have formed near the receiving port.

[0016] Therefore, when the hydrogen concentration detected by the hydrogen sensor exceeds a threshold value, the control device executes a warning process to warn of blockage of the chute.

[0017] This allows workers to detect the formation of bridges near the receiving port early and take steps to eliminate the bridges before the risk of explosion increases.

[0018] The present invention [3] includes the ash treatment system of [1] above, further comprising a control device capable of receiving a signal from the hydrogen sensor, and wherein the control device performs a water injection process to add cooling water to the ash treatment device when the hydrogen concentration detected by the hydrogen sensor exceeds a threshold value.

[0019] With this configuration, if the alkalinity of the cooling water becomes excessively high, there is a possibility that the amount of hydrogen gas generated will increase.

[0020] If a bridge occurs when the amount of hydrogen gas generated increases, the risk of an explosion may increase in a short period of time.

[0021] Therefore, when the hydrogen concentration detected by the hydrogen sensor exceeds a threshold value, the control device executes a water injection process to add cooling water to the ash treatment device.

[0022] This reduces the amount of hydrogen gas generated and suppresses an increase in the risk of explosion if a bridge occurs.

[0023] The present invention [4] includes the ash treatment system of any one of [1] to [3] above, wherein the ash treatment system further comprises a control device capable of receiving a signal from the hydrogen sensor and a post-combustion grate drive device that drives the post-combustion grate of the incinerator, and the control device controls the post-combustion grate drive device to adjust the drive speed of the post-combustion grate when the hydrogen concentration detected by the hydrogen sensor exceeds a threshold value.

[0024] With this configuration, the driving speed of the post-combustion grate can be adjusted based on the hydrogen concentration detected by the hydrogen sensor so that the amount of hydrogen gas generated does not increase excessively.

[0025] The present invention [5] includes the ash treatment system of any one of [1] to [4] above, in which the ash treatment device includes an ash extrusion device that cools the ash with water and extrudes the cooled ash, and the receiving port is the receiving port of the ash extrusion device.

[0026] The present invention [6] includes the ash treatment system according to the above [5], wherein the ash extrusion device has a cooling water tank for immersing the ash in water to cool it.

[0027] The present invention [7] includes the ash treatment system according to the above [5], wherein the ash extrusion device has a water sprinkling means for sprinkling water on the ash.

[0028] The present invention [8] includes the ash treatment system of any one of [5] to [7] above, wherein the ash treatment system further comprises a control device capable of receiving a signal from the hydrogen sensor, the ash extrusion device further comprises a scraper for extruding the ash and a scraper drive device for driving the scraper, and the control device controls the scraper drive device to adjust the drive timing of the scraper when the hydrogen concentration detected by the hydrogen sensor exceeds a threshold value.

[0029] With this configuration, the timing of driving the scraper can be adjusted based on the hydrogen concentration detected by the hydrogen sensor so that the amount of hydrogen gas generated does not increase excessively.

[0030] The present invention [9] includes the ash treatment system of the above [1], wherein the ash treatment device cools the ash with water and includes a water-cooled conveyor that transports the cooled ash, and the receiving port is the receiving port of the water-cooled conveyor.

[0031] According to the ash treatment system of the present invention, the occurrence of bridging near the receiving port can be detected at an early stage.

[0032] FIG. 1 is a block diagram showing a waste incineration facility equipped with an ash treatment system according to one embodiment of the present invention. FIG. 2 is a schematic diagram of the ash treatment system shown in FIG. 1. FIG. 3 is a cross-sectional view of the ash extrusion device shown in FIG. 2. FIG. 4 is a block diagram for explaining the control of the ash treatment system shown in FIG. 2. FIG. 5 is a flowchart of ventilation processing, which is an example of the control of the ash treatment system shown in FIG. 2. FIG. 6 is a flowchart of warning processing, which is an example of the control of the ash treatment system shown in FIG. 2. FIG. 7 is an explanatory diagram for explaining modified example (2). FIG. 8 is an explanatory diagram for explaining modified example (3), showing a water-sealed water-cooled conveyor. FIG. 9 is an explanatory diagram for explaining modified example (3), showing a sprinkler-type water-cooled conveyor.

[0033] 1. Ash Treatment System As shown in Figure 1, ash treatment system 1 treats ash discharged from incinerator A in a waste incineration facility. Specifically, ash treatment system 1 cools the ash discharged from incinerator A and transports it to ash pit B. Ash pit B stores the ash cooled by ash treatment system 1. The ash contains at least bottom ash. The ash may also contain fly ash. The bottom ash contains incineration ash. The bottom ash may also contain dust ash that has fallen through gaps in the grate of incinerator A.

[0034] The ash treatment system 1 includes a chute 2 (see FIG. 2 ), an ash treatment device 3 , and a hydrogen concentration detection system 4 .

[0035] In the following description, the ash treatment system 1 will be described as being applied to a stoker (fire grate) type incinerator, as shown in Figure 2. The stoker type incinerator is equipped with a drying grate A11, a combustion grate A12, and a post-combustion grate A13, in that order, from a waste inlet A1 to an ash outlet A2.

[0036] (1) Chute The chute 2 guides the incineration ash to the ash treatment device 3. More specifically, the chute 2 guides the incineration ash to the ash pushing device 31 described below. One end of the chute 2 is connected to the discharge outlet A2 of the incinerator A. The other end of the chute 2 is connected to the receiving port 311A ​​of the ash pushing device 31 (see Figure 3).

[0037] (2) Ash Treatment Device The ash treatment device 3 cools the ash with water and transports the cooled ash toward the ash pit B. In detail, the ash treatment device 3 includes an ash extrusion device 31, a dust ash transport path 32 as an example of an upstream transport path, a boiler-adhered ash transport path 33 as an example of an upstream transport path, and a downstream transport path 34.

[0038] (2-1) Ash Push-Out Device As shown in Figure 3, the ash push-out device 31 cools ash with water and pushes out the cooled ash. In this embodiment, the ash push-out device 31 is a water-sealed type. More specifically, the ash push-out device 31 includes a cooling water tank 311, a scraper 312, and a scraper drive device 313.

[0039] The cooling water tank 311 is a water tank for immersing the ash in water to cool it. The cooling water tank 311 has a roughly box-like shape extending horizontally. Cooling water W is stored inside the cooling water tank 311. Ash that passes through the chute 2 and enters the cooling water tank 311 is cooled by the cooling water W. The cooling water tank 311 has an inlet 311A ​​and an outlet 311B. In other words, the ash extrusion device 31 has the inlet 311A.

[0040] The receiving port 311A ​​is disposed on the upper wall of the cooling water tank 311. The receiving port 311A ​​is located above the water level L of the cooling water W. The receiving port 311A ​​is capable of receiving ash. The ash that has passed through the chute 2 passes through the receiving port 311A ​​and enters the cooling water tank 311.

[0041] The discharge outlet 311B is disposed at one end of the cooling water tank 311 in the horizontal direction. The discharge outlet 311B is disposed apart from the inlet 311A ​​in the horizontal direction. The discharge outlet 311B is located above the water level L of the cooling water W. The ash immersed in the cooling water W is discharged out of the cooling water tank 311 through the discharge outlet 311B.

[0042] The bottom wall 3111 of the cooling water tank 311 has a deepest portion 3111A and an inclined portion 3111B. The deepest portion 3111A is located below the inlet 311A ​​at a distance. The depth of the cooling water W is greatest at the deepest portion 3111A. The inclined portion 3111B inclines upward as it approaches the outlet 311B from the deepest portion 3111A. The ash in the cooling water tank 311 is pushed by the scraper 312 from the deepest portion 3111A toward the outlet 311B, moves up the inclined portion 3111B, and is discharged from the outlet 311B.

[0043] Scraper 312 is disposed in cooling water tank 311. Scraper 312 pushes out ash from cooling water tank 311. Specifically, scraper 312 pushes ash on deepest portion 3111A toward discharge outlet 311B. Scraper 312 can repeatedly move between a first position (see phantom lines in FIG. 3 ) and a second position (see solid lines in FIG. 3 ). When scraper 312 moves from the first position to the second position, it pushes ash on deepest portion 3111A toward discharge outlet 311B.

[0044] The scraper driving device 313 drives the scraper 312. The scraper driving device 313 may be, for example, a hydraulic cylinder.

[0045] (2-2) Falling Ash Conveying Path As shown in FIG. 2, the falling ash conveying path 32 is a conveying path for conveying falling ash to the ash pushing device 31. The falling ash conveying path 32 is arranged below the incinerator A. The falling ash conveying path 32 is arranged below the drying grate A11, the combustion grate A12, and the post-combustion grate A13. The falling ash conveying path 32 can receive falling ash that has fallen from each of the drying grate A11, the combustion grate A12, and the post-combustion grate A13. The falling ash conveying path 32 is connected to the ash pushing device 31, for example, via a chute 2. A drag chain conveyor is arranged within the falling ash conveying path 32. The falling ash within the falling ash conveying path 32 is conveyed by the drag chain conveyor toward the ash pushing device 31.

[0046] (2-3) Boiler-Adhered Ash Conveying Path The boiler-adhered ash conveying path 33 is a conveying path for conveying fly ash adhering to the boiler 5 to the ash pushing device 31. The boiler-adhered ash conveying path 33 is connected to the ash pushing device 31. The boiler 5 is provided in an exhaust gas treatment device for treating exhaust gas discharged from the incinerator A. The boiler 5 boils water using the heat of the exhaust gas. The steam obtained by the boiler 5 is used, for example, for power generation. Fly ash contained in the exhaust gas adheres to the boiler 5. The fly ash adhering to the boiler 5 is removed, for example, by soot blowing and conveyed to the ash pushing device 31 through the boiler-adhered ash conveying path 33. A scraper conveyor is arranged in the boiler-adhered ash conveying path 33. The fly ash in the boiler-adhered ash conveying path 33 is conveyed by the scraper conveyor toward the ash pushing device 31.

[0047] (2-4) Downstream Conveying Path The downstream conveying path 34 is a conveying path for conveying the ash pushed out from the ash pusher 31 toward the ash pit B. The downstream conveying path 34 is capable of receiving the ash pushed out from the ash pusher 31. A scraper conveyor is disposed within the downstream conveying path 34. The ash within the downstream conveying path 34 is conveyed toward the ash pit B by the scraper conveyor.

[0048] (3) Hydrogen Concentration Detection System The hydrogen concentration detection system 4 detects the hydrogen concentration in the ash treatment device 3.

[0049] In the ash treatment device 3, the ash (mainly alkaline in composition) is cooled with cooling water W (see FIG. 3 ), which makes the cooling water W alkaline. In particular, when the cooling water W is circulated, the alkalinity of the cooling water W increases. This causes metals (e.g., aluminum) contained in the ash to react with the alkaline cooling water W, generating hydrogen. If the generated hydrogen accumulates, there is a possibility that an explosion will occur due to the accumulated hydrogen.

[0050] Therefore, in the present invention, the hydrogen concentration in the ash treatment device 3 is monitored by the hydrogen concentration detection system 4. More specifically, the hydrogen concentration detection system 4 includes a plurality of hydrogen sensors 41 and a control device 42. In other words, the ash treatment system 1 includes a plurality of hydrogen sensors 41.

[0051] (3-1) Hydrogen Sensor The multiple hydrogen sensors 41 are capable of measuring the hydrogen concentration within the ash treatment device 3. In other words, the hydrogen concentration detection system 4 is capable of measuring the hydrogen concentration at multiple points within the ash treatment device 3. In detail, the multiple hydrogen sensors 41 include multiple upstream hydrogen sensors 41A, 41B, 41C, 41D, multiple downstream hydrogen sensors 41E, 41F, and an inlet hydrogen sensor 41G.

[0052] The upstream hydrogen sensors 41A, 41B are capable of measuring the hydrogen concentration within the dust ash transport path 32. The upstream hydrogen sensors 41A, 41B are arranged apart from each other in the direction in which the dust ash transport path 32 extends. As a result, the upstream hydrogen sensors 41A, 41B continuously measure the hydrogen concentration at two separate locations within the dust ash transport path 32. The number of hydrogen sensors 41 attached to the dust ash transport path 32 is not limited. The number of hydrogen sensors 41 attached to the dust ash transport path 32 may be one, or may be three or more.

[0053] The upstream hydrogen sensors 41C, 41D are capable of measuring the hydrogen concentration within the boiler adhesion ash transport path 33. The upstream hydrogen sensors 41C, 41D are arranged apart from each other in the direction in which the boiler adhesion ash transport path 33 extends. As a result, the upstream hydrogen sensors 41C, 41D continuously measure the hydrogen concentration at two separate locations within the boiler adhesion ash transport path 33. The number of hydrogen sensors 41 attached to the boiler adhesion ash transport path 33 is not limited. The number of hydrogen sensors 41 attached to the boiler adhesion ash transport path 33 may be one, or may be three or more.

[0054] The downstream hydrogen sensors 41E, 41F are capable of measuring the hydrogen concentration within the downstream transport path 34. The downstream hydrogen sensors 41E, 41F are positioned apart from each other in the direction in which the downstream transport path 34 extends. As a result, the downstream hydrogen sensors 41E, 41F continuously measure the hydrogen concentration at two separate locations within the downstream transport path 34. The number of hydrogen sensors 41 attached to the downstream transport path 34 is not limited. The number of hydrogen sensors 41 attached to the downstream transport path 34 may be one, or may be three or more.

[0055] 3, the receiving port hydrogen sensor 41G is capable of measuring the hydrogen concentration in the receiving port 311A ​​of the ash pusher 31. The receiving port hydrogen sensor 41G continuously measures the hydrogen concentration in the receiving port 311A ​​of the ash pusher 31.

[0056] Each of the multiple hydrogen sensors 41 is preferably a wireless hydrogen detection device. Alternatively, each of the multiple hydrogen sensors 41 may be a wired hydrogen detection device. Generated hydrogen accumulates in unexpected locations within the ash treatment device 3. Therefore, it is preferable to perform multi-point monitoring of hydrogen concentration using small, wireless hydrogen sensors and communication devices that can be easily installed and used anywhere. Multi-point monitoring of hydrogen concentration allows the hydrogen accumulation status and accident risk to be predicted based on the trend in hydrogen concentration at each hydrogen sensor installation location. Furthermore, when an explosion risk is determined to have increased, explosions can be avoided by measures such as promoting ventilation throughout the entire facility or pinpointing and forcing ventilation in areas where the explosion risk has increased. Note that if the hydrogen concentration gradually increases and an explosion risk is determined to have increased, promoting ventilation throughout the facility is preferable. However, if an explosion risk is determined to have increased due to a sudden increase in hydrogen concentration, pinpointing and forcing ventilation (such as air blowing + venting to the atmosphere) in areas where the explosion risk has increased is preferable.

[0057] (3-2) Control Device As shown in FIGS. 2 and 3, the control device 42 is capable of receiving signals from each of the multiple hydrogen sensors 41.

[0058] As shown in Figure 4, the ash treatment system 1 may further include a display device 51, a warning light 52, a fan 53 in the dust ash transport path 32, a fan 54 in the boiler adhesion ash transport path 33, a fan 55 in the downstream transport path 34, a fan 56 in the ash extrusion device 31, and a post-combustion grate drive device 57.

[0059] The display device 51 is disposed, for example, in a control room of the waste incineration facility. The warning light 52 is attached, for example, to the ash pusher 31. The fan 53 is attached to the falling dust ash transport path 32. The fan 54 is attached to the boiler adhesion ash transport path 33. The fan 55 is attached to the downstream transport path 34. The fan 56 is attached to the ash pusher 31. The post-combustion grate drive device 57 is connected to the post-combustion grate A13. The post-combustion grate drive device 57 drives the post-combustion grate A13 of the incinerator A. The control device 42 may be integrated with other control devices of the incinerator.

[0060] The control device 42 controls, via wireless or wired connection, the display device 51, the warning light 52, the fan 53 of the dust ash transport path 32, the fan 54 of the boiler adhesion ash transport path 33, the fan 55 of the downstream transport path 34, the fan 56 of the ash extrusion device 31, the post-combustion grate drive device 57, and the scraper drive device 313.

[0061] 5, the control device 42 monitors the hydrogen concentration in the dust ash transport path 32 based on signals from the upstream hydrogen sensors 41A, 41B (see FIG. 2), and when the hydrogen concentration in the dust ash transport path 32 exceeds a threshold value (first threshold value) (S1: YES), the control device 42 performs ventilation processing for the dust ash transport path 32 (S2). In the ventilation processing for the dust ash transport path 32, the control device 42 operates a fan 53 (see FIG. 4) to ventilate the dust ash transport path 32.

[0062] In addition, in parallel with the processing for the dust ash transport path 32, the control device 42 also monitors the hydrogen concentration inside the boiler adhesion ash transport path 33 and the downstream transport path 34, and performs ventilation processing if the hydrogen concentration exceeds a threshold value.

[0063] In detail, the control device 42 monitors the hydrogen concentration in the boiler adhesion ash transport path 33 based on signals from the upstream hydrogen sensors 41C, 41D (see FIG. 2), and when the hydrogen concentration in the boiler adhesion ash transport path 33 exceeds a threshold value (second threshold value), the control device 42 performs a ventilation process for the boiler adhesion ash transport path 33. In the ventilation process for the boiler adhesion ash transport path 33, the control device 42 operates a fan 54 (see FIG. 4) to ventilate the boiler adhesion ash transport path 33. The second threshold value can be set independently of the first threshold value. The second threshold value may be the same as or different from the first threshold value.

[0064] The control device 42 also monitors the hydrogen concentration in the downstream transfer path 34 based on signals from the downstream hydrogen sensors 41E, 41F (see FIG. 2 ). When the hydrogen concentration in the downstream transfer path 34 exceeds a threshold value (third threshold value), the control device 42 performs ventilation of the downstream transfer path 34. In the ventilation of the downstream transfer path 34, the control device 42 activates a fan 55 (see FIG. 4 ) to ventilate the downstream transfer path 34. The third threshold value can be set independently of the first and second threshold values. The third threshold value may be the same as or different from the first and second threshold values. The third threshold value is preferably higher than the first and second threshold values.

[0065] Then, when the hydrogen concentration becomes equal to or lower than the safe value (S1: NO, S3: YES, S4: YES), the control device 42 stops the ventilation process (S5).

[0066] As shown in FIG. 6, the control device 42 monitors the hydrogen concentration in the receiving port 311A ​​of the ash extrusion device 31 based on a signal from the receiving port hydrogen sensor 41G (see FIG. 3). If the hydrogen concentration detected by the receiving port hydrogen sensor 41G exceeds a threshold value (fourth threshold value) (S11: YES), the control device 42 executes a warning process (S12). The fourth threshold value can be set independently of the first, second, and third threshold values. The fourth threshold value may be the same as or different from the first, second, and third threshold values. The fourth threshold value is preferably higher than the first, second, and third threshold values.

[0067] Here, if the hydrogen concentration detected by the receiving port hydrogen sensor 41G exceeds a threshold value (fourth threshold value), and if it adheres to and grows on the inner wall of the chute 2 (see Figure 3), a state called a "bridge" will occur in which the inside of the chute 2 is blocked.As a result of the chute 2 being blocked, it is possible that hydrogen in the ash extrusion device 31, which would have escaped to the incinerator side if the chute 2 were not blocked, will remain near the receiving port 311A.

[0068] Therefore, in the warning process, the control device 42, for example, displays on the display device 51 (see Figure 4) that the chute 2 may be blocked, and activates the warning light 52 (see Figure 4) to warn of the blockage of the chute 2.

[0069] Furthermore, if the hydrogen concentration detected by the inlet hydrogen sensor 41G exceeds the threshold value, it is possible that the alkalinity of the cooling water has become excessively strong, causing an increase in the amount of hydrogen generated.

[0070] Therefore, the control device 42 may execute a water injection process to add cooling water together with the warning process (S12). Note that the water injection process may be executed independently of the warning process (S12) based on thresholds and safety values ​​different from those used in the warning process (S12).

[0071] When the hydrogen concentration becomes equal to or lower than the safe value (S11: NO, S13: YES, S14: YES), the control device 42 cancels the warning (S15).

[0072] The hydrogen concentration distribution at each location of the hydrogen sensor, the threshold value of the hydrogen concentration, and the safety value may be determined by machine learning or the like.

[0073] 2. Effects (1) As shown in FIG. 3, the ash treatment system 1 can measure the hydrogen concentration in the receiving port 311A ​​of the ash pusher 31 using the receiving port hydrogen sensor 41G.

[0074] Therefore, if a bridge occurs near the inlet 311A, the inlet hydrogen sensor 41G can detect an increase in the hydrogen concentration inside the inlet 311A.

[0075] Therefore, the occurrence of a bridge near the receiving opening 311A ​​can be detected early.

[0076] As a result, bridge elimination work can be carried out before the risk of explosion increases.

[0077] (2) According to the ash processing system 1, if the chute 2 is blocked by a bridge near the receiving port 311A, the hydrogen gas generated in the ash extrusion device 31 may accumulate near the receiving port 311A, and the hydrogen concentration near the receiving port 311A ​​may increase.

[0078] Therefore, if the hydrogen concentration detected by the inlet hydrogen sensor 41G exceeds the threshold value, it is suspected that a bridge may have formed near the inlet 311A.

[0079] Therefore, as shown in Figure 6, if the hydrogen concentration detected by the receiving port hydrogen sensor 41G exceeds the threshold value (S11: YES), the control device 42 executes a warning process (S12) to warn of blockage of the chute 2.

[0080] This allows workers to detect the occurrence of a bridge near the receiving port 311A ​​at an early stage and carry out work to eliminate the bridge before the risk of explosion increases.

[0081] (3) According to the ash treatment system 1, if the alkalinity of the cooling water becomes excessively high, the amount of hydrogen gas generated may increase.

[0082] If a bridge occurs when the amount of hydrogen gas generated increases, the risk of an explosion may increase in a short period of time.

[0083] Therefore, when the hydrogen concentration detected by the inlet hydrogen sensor 41G exceeds the threshold value, the control device 42 may execute a warning process (S12) and a water injection process to add cooling water to the ash treatment device.

[0084] This reduces the amount of hydrogen gas generated and suppresses an increase in the risk of explosion if a bridge occurs.

[0085] 3. Modifications Modifications will be described below. In the modifications, the same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0086] (1) The ash treatment device 3 does not need to have the boiler-adhered ash transport path 33. The boiler-adhered ash (fly ash) may be transported to a fly ash treatment facility separate from the ash treatment device 3 and solidified there.

[0087] (2) As shown in Fig. 7, the ash pusher 31 may be of a sprinkler type. Specifically, the ash pusher 31 sprinkles cooling water onto the ash in the cooling water tank 311 without immersing the ash in the cooling water tank 311. The ash pusher 31 has a nozzle 61 as an example of a sprinkler means. The nozzle 61 sprinkles water onto the ash in the cooling water tank 311 to cool it. The cooled ash is pushed by a scraper 312 and discharged from a discharge port 311B.

[0088] (3) The ash processing device 3 may be provided with a water-cooled conveyor 71 instead of the ash pusher 31. The water-cooled conveyor 71 may be a water-sealed type, as shown in Fig. 8, in which the ash is cooled by immersing it in cooling water W stored in the water-cooled conveyor 71, or a water-spray type, as shown in Fig. 9, in which the ash is cooled by spraying water from nozzles 72.

[0089] The water-cooled conveyor 71 cools the ash with water and transports the cooled ash. A drag chain conveyor is arranged inside the water-cooled conveyor 71. The ash in the water-cooled conveyor 71 is transported by the drag chain conveyor toward the ash pit B (see Figure 1).

[0090] The receiving port hydrogen sensor 41G may be capable of measuring the hydrogen concentration within the receiving port 311A ​​of the water-cooled conveyor 71.

[0091] According to this modified example, a water-cooled conveyor 71 is provided instead of the ash extrusion device 31, and when the ash is cooled using the water-cooled conveyor 71, the receiving port hydrogen sensor 41G can be used to monitor the hydrogen concentration within the water-cooled conveyor 71, which is assumed to be the main source of hydrogen gas.

[0092] (4) The water-cooled conveyor 71 may be continuous with the dust ash transport path 32 (see FIG. 2).

[0093] (5) When the hydrogen concentration detected by the inlet hydrogen sensor 41G (see Figure 3) exceeds a threshold value, the control device 42 may control the post-combustion grate driving device 57 to adjust the driving speed of the post-combustion grate A13 (see Figure 2), as shown in Figure 4.

[0094] According to this modification, the driving speed of the post-combustion grate A13 can be adjusted based on the hydrogen concentration detected by the inlet hydrogen sensor 41G so that the amount of hydrogen gas generated does not increase excessively.

[0095] In detail, when the hydrogen concentration detected by the inlet hydrogen sensor 41G exceeds a threshold value, the control device 42 controls the post-combustion grate driving device 57 to slow down the driving speed of the post-combustion grate A13.

[0096] By slowing down the driving speed of the post-combustion grate A13, the amount of incineration ash supplied to the ash extrusion device 31 per unit time can be reduced, and the amount of hydrogen generated in the ash extrusion device 31 can be reduced.

[0097] (6) When the hydrogen concentration detected by the inlet hydrogen sensor 41G (see Figure 3) exceeds a threshold value, the control device 42 may control the scraper driving device 313 to adjust the driving timing of the scraper 312 (see Figure 3).

[0098] According to this modification, the drive timing of the scraper 312 can be adjusted based on the hydrogen concentration detected by the inlet hydrogen sensor 41G so that the amount of hydrogen gas generated does not increase excessively.

[0099] More specifically, when the hydrogen concentration detected by the inlet hydrogen sensor 41G exceeds the threshold value, the control device 42 controls the scraper driving device 313 to adjust the drive timing of the scraper 312 so that the drive interval of the scraper 312 is longer than the set value. The control device 42 also controls the scraper driving device 313 to adjust the drive timing of the scraper 312 so that the drive timing of the scraper 312 is delayed relative to the drive timing of the post-combustion grate driving device 57.

[0100] (7) The same effects as those of the embodiment can be obtained in the modified examples (1) to (6). Note that the above invention is provided as an exemplary embodiment of the present invention, but this is merely an example and should not be interpreted as limiting. Modifications of the present invention that are obvious to those skilled in the art are included in the scope of the claims below.

[0101] The ash treatment system of the present invention can be used for treating ash at a waste incineration facility.

[0102] 1 Ash treatment system 2 Chute 3 Ash treatment device 31 Ash extrusion device 311 Cooling water tank 311A ​​Receiving port 312 Scraper 313 Scraper drive device 41G Receiving port hydrogen sensor (an example of a hydrogen sensor) 42 Control device 57 Post-combustion grate drive device 61 Nozzle (an example of a water sprinkling means) 71 Water-cooled conveyor A Incinerator A13 Post-combustion grate

Claims

1. An ash treatment system for treating ash discharged from an incinerator, comprising: an ash treatment device that cools the ash with water and transports the cooled ash; and a hydrogen sensor, wherein the ash treatment device has an inlet for receiving the ash, and the hydrogen sensor is capable of measuring the hydrogen concentration within the inlet.

2. The ash treatment system further comprises a chute that guides the ash discharged from the incinerator to the ash treatment device, the chute having one end connected to the incinerator and the other end connected to the receiving port of the ash treatment device, and a control device capable of receiving a signal from the hydrogen sensor, wherein the control device executes a warning process to warn of blockage of the chute if the hydrogen concentration detected by the hydrogen sensor exceeds a threshold value.The ash treatment system described in claim 1.

3. The ash treatment system of claim 1, further comprising a control device capable of receiving a signal from the hydrogen sensor, wherein the control device performs a water injection process to add cooling water to the ash treatment device when the hydrogen concentration detected by the hydrogen sensor exceeds a threshold value.

4. The ash handling system of claim 1, further comprising: a control device capable of receiving a signal from the hydrogen sensor; and a post-combustion grate drive device that drives the post-combustion grate of the incinerator, wherein the control device controls the post-combustion grate drive device to adjust the drive speed of the post-combustion grate when the hydrogen concentration detected by the hydrogen sensor exceeds a threshold value.

5. The ash processing system of claim 1, wherein the ash processing device comprises an ash pushing device that cools the ash with water and pushes out the cooled ash, and the receiving port is the receiving port of the ash pushing device.

6. The ash treatment system according to claim 5, wherein the ash extrusion device has a cooling water tank for immersing the ash in water to cool it.

7. The ash treatment system according to claim 5, wherein the ash pusher has a water sprinkling means for sprinkling water on the ash.

8. The ash processing system of claim 5, further comprising a control device capable of receiving a signal from the hydrogen sensor, the ash extrusion device further comprising a scraper for pushing out the ash, and a scraper drive device for driving the scraper, and the control device controls the scraper drive device to adjust the drive timing of the scraper when the hydrogen concentration detected by the hydrogen sensor exceeds a threshold value.

9. The ash handling system of claim 1, wherein the ash handling device comprises a water-cooled conveyor that cools the ash with water and transports the cooled ash, and the receiving port is an receiving port of the water-cooled conveyor.

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