Incineration facility and incinerated ash removal method

Abstract

To collect incinerated ash without stopping incineration of dewatered sludge by an incineration furnace.SOLUTION: An incineration facility comprises an incinerator that incinerates dewatered sludge, an exhaust gas flow path that guides exhaust gas generated by the incineration of the dewatered sludge, and an incineration ash removal mechanism that injects high-pressure gas onto incineration ash accumulated on an inner surface of the exhaust gas flow path.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an incineration facility and a method for removing incineration ash. [Background technology]

[0002] The process at sewage treatment facilities that treat sewage such as domestic wastewater includes a process of purifying the sewage and separating and extracting sludge from the sewage, a process of concentrating and dewatering the separated and extracted sludge to produce dewatered sludge, and a process of incinerating the dewatered sludge.

[0003] Regarding the process of incinerating dewatered sludge, for example, Patent Document 1 describes a "method of incinerating sewage sludge in which dewatered sludge including excess sludge is incinerated in a fluidized incinerator, the components of the dewatered sludge to be incinerated in the fluidized incinerator are adjusted so that a value calculated from the contents of Na, K, Ca, Mg, Al, and Fe in the dewatered sludge supplied to the fluidized incinerator and the P (phosphorus) content is equal to or greater than a predetermined value, and the incineration ash is collected to reuse the phosphorus component in the incineration ash." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-120164 A Summary of the Invention [Problem to be solved by the invention]

[0005] According to the technology described in Patent Document 1, when dewatered sewage sludge containing phosphorus is incinerated at 840 to 900°C in a fluidized incinerator, the amount of incineration ash that adheres to and accumulates on the inner surface of the exhaust gas passage on the incinerator outlet side can be reduced. However, it is difficult to completely prevent the incineration ash from adhering to and accumulating on the inner surface of the exhaust gas passage, and it is still necessary to periodically collect the incineration ash that has adhered and accumulated.

[0006] FIG. 2 shows an example of the configuration of a conventional incineration facility 200 for incinerating dewatered sludge.

[0007] The incineration equipment 200 includes an incinerator 201 that incinerates dewatered sludge 201P, an exhaust gas flow path 202 that guides exhaust gas generated by the incineration of the dewatered sludge 201P to a heat exchanger 203, and a heat exchanger 203 that transfers the thermal energy of the exhaust gas to another heat medium.

[0008] The exhaust gas flow passage 202 has a vertical portion 202V 1 , horizontal portion 202H, and vertical portion 202V 2 The exhaust gas from the incinerator 201 is discharged through a vertical section 202V 1 , horizontal portion 202H, and vertical portion 202V 2 and reaches the heat exchanger 203. An inspection hatch 204 is provided in the center of the horizontal portion 202H of the exhaust gas passage 202, through which an operator who collects the incineration ash 205 accumulated on the inner surface of the exhaust gas passage 202 can enter the inside of the exhaust gas passage 202.

[0009] In the incineration facility 200, when the dewatered sludge 201P is incinerated in the incinerator 201, the incineration ash 205 is likely to accumulate in the horizontal portion 202H of the exhaust gas flow path 202. When collecting the incineration ash 205 accumulated in the horizontal portion 202H, a worker needs to enter the inside of the exhaust gas flow path 202. For this reason, before the collection work, it is necessary to stop the incineration of the dewatered sludge 201P by the incinerator 201 and wait until the incinerator 201 and the exhaust gas flow path 202 are cooled. In addition, after the collection work, it is necessary to burn fuel in the incinerator 201 again to heat it, and then to resume the incineration of the dewatered sludge 201P. For this reason, this series of work takes about 10 days, which causes problems such as delays in the incineration process and the process before that, a huge amount of fuel is required to reheat the incinerator 201, which increases fuel costs, and a large environmental load.

[0010] The present invention has been made in view of the above circumstances, and has an object to make it possible to collect incineration ash without stopping the incineration of dewatered sludge in an incinerator. [Means for solving the problem]

[0011] The present application includes a number of means for solving at least part of the above problems, examples of which are as follows.

[0012] In order to solve the above problems, one embodiment of the incineration equipment of the present invention comprises an incinerator for incinerating dewatered sludge, an exhaust gas flow path for guiding exhaust gas generated by the incineration of the dewatered sludge, and an incineration ash removal mechanism for injecting high-pressure gas at incineration ash accumulated on the inner surface of the exhaust gas flow path.

[0013] The exhaust gas flow path can be equipped with an outlet for discharging the incineration ash peeled off and moved by the incineration ash removal mechanism, and the incineration ash removal mechanism can be equipped with a plurality of injection nozzles at different distances from the outlet, and the high-pressure gas can be sprayed in sequence from the injection nozzle located farthest from the outlet to the injection nozzle located closest to the outlet.

[0014] The incineration equipment may include a first valve that controls the inflow of the exhaust gas to a portion of the exhaust gas flow path where the incineration ash removal mechanism is provided, a bypass flow path that guides the exhaust gas while the inflow of the exhaust gas to the portion of the exhaust gas flow path where the incineration ash removal mechanism is provided is regulated by the first valve, and a second valve that controls the inflow of the exhaust gas from the exhaust gas flow path to the bypass flow path, and the incineration ash removal mechanism may operate with the first valve closed and the second valve open.

[0015] The incineration facility may include a control device that controls at least one of the incineration ash removal mechanism, the first valve, and the second valve.

[0016] The incineration equipment may be equipped with a heat exchanger that transfers the thermal energy of the exhaust gas to another heat medium, and the exhaust gas flow path and the bypass flow path may guide the exhaust gas to the heat exchanger.

[0017] The incineration facility may be provided with an inspection hatch for checking the incineration ash accumulated on the inner surface of the exhaust gas flow path.

[0018] Another aspect of the incineration ash removal method of the present invention includes providing a plurality of injection nozzles in an exhaust gas flow path that guides exhaust gas generated by incineration of dewatered sludge, and injecting high-pressure gas into the plurality of injection nozzles. Effect of the Invention

[0019] According to the present invention, incineration ash can be collected without stopping the incineration of dewatered sludge in the incinerator.

[0020] Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of an incineration facility according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing an example of the configuration of a conventional incineration facility. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all the drawings for explaining the embodiment, the same members are generally given the same reference numerals, and the repeated description thereof will be omitted. In the following embodiments, the components (including element steps, etc.) are not necessarily essential, except when specifically stated otherwise or when it is clearly considered essential in principle. In addition, when it is said that "A is made of," "A is made of," "has A," or "includes A," other elements are not excluded, except when it is specifically stated that only that element is included. Similarly, in the following embodiments, when referring to the shape, positional relationship, etc. of components, etc., it is intended to include those that are substantially similar to or similar to the shape, etc., except when it is specifically stated otherwise or when it is clearly considered not to be the case in principle.

[0023] <Configuration example of incineration facility 10 according to one embodiment of the present invention> 1 shows an example of the configuration of an incineration facility 10 according to one embodiment of the present invention. The incineration facility 10 is designed to allow workers to collect incineration ash without entering the exhaust gas flow path.

[0024] The incineration equipment 10 has a bypass flow path 11, a valve 12, and a valve 13 in comparison with the conventional incineration equipment 200 (FIG. 2). 1 ,12 2 ,13 1 ,13 2 The incineration ash removal mechanism 15, discharge port 18, valve 19, hopper 20, and control device 21 have been added.

[0025] The incinerator 201, exhaust gas flow path 202, heat exchanger 203, and inspection hatch 204, which are common to the incineration system 10 and the conventional incineration system 200, are given the same reference numerals and their explanations are omitted.

[0026] The bypass passage 11 is a vertical portion 202V of the exhaust gas passage 202. 1 and vertical part 202V 2 The valve 12 is provided to connect the 1 is a vertical portion 202V of the exhaust gas flow passage 202 1The valve 12 is provided at the connection point between the bypass flow path 11 and the 2 is a vertical portion 202V of the exhaust gas flow passage 202 2 The valve 12 is provided at the connection point between the bypass flow path 11 and the 1 ,12 2 is a vertical portion 202V of the exhaust gas flow passage 202 1 ,202V 2 The bypass flow passage 11 is opened and closed relative to the valve 12. 1 ,12 2 corresponds to the second valve of the present invention.

[0027] Valve 13 1 is a vertical portion 202V of the exhaust gas flow passage 202 1 and the horizontal portion 202H. 2 The horizontal portion 202H and the vertical portion 202V of the exhaust gas flow passage 202 are 2 Valve 13 is provided at the connection point with 1 ,13 2 is a vertical portion 202V of the exhaust gas flow passage 202 1 ,202V 2 In contrast, the horizontal portion 202H of the exhaust gas passage 202 where the incineration ash 205 is likely to accumulate is opened and closed. 1 ,13 2 corresponds to the first valve of the present invention.

[0028] The inspection hatch 14 is provided on the side of the horizontal portion 202H of the exhaust gas passage 202. The inspection hatch 14 is used by workers to check the amount of accumulated incineration ash 205 and to manually peel off and move the accumulated incineration ash 205 using a cleaning tool such as a rod-shaped scraper.

[0029] The incineration ash removal mechanism 15 is composed of a plurality of injection nozzles 151, a valve 152 provided on each injection nozzle 151, an air tank 153, and a compressor 154. Half of the injection nozzles 151 are arranged penetrating the upper wall surface of the horizontal part 202H at equal intervals centered on the inspection hatch 204. Each injection nozzle 151 is arranged at an angle to the center of the horizontal part 202H where the discharge port 18 is provided. The arrangement of the injection nozzles 151 is not limited to the example shown in the figure, and may be other arrangements. Each injection nozzle 151 is connected to an air tank 153 that accumulates high-pressure gas (air, etc.) compressed by the compressor 154 via a valve 152. The injection nozzle 151 injects high-pressure gas when the valve 152 is opened.

[0030] The discharge outlet 18 is provided at the center lower part of the horizontal part 202H of the exhaust gas passage 202. The discharge outlet 18 discharges the incineration ash 205 from the exhaust gas passage 202 to a hopper 20 arranged below. A valve 19 is provided at the discharge outlet 18. The valve 19 is for opening and closing the discharge outlet 18. The hopper 20 receives the incineration ash 205 discharged from the discharge outlet 18 and guides it to a device such as a phosphorus separation device (not shown). Note that a container for storing the incineration ash 205 may be arranged instead of the hopper 20.

[0031] The control device 21 controls the valve 12 1 ,12 2 ,13 1 ,13 2 , 152, and 19, and the operation of a compressor 154. Note that control lines from the control device 21 to each valve are omitted from the illustration.

[0032] <Operation of incineration equipment 10> Next, the operation of the incineration facility 10 will be described. It is assumed that the incineration facility 10 continues incineration of the dewatered sludge 201P by the incinerator 201 without stopping. The collection work of the incineration ash 205 may be started in response to an operation from the user to the control device 21, or the timing of execution may be set in advance.

[0033] When the incineration ash 205 is not to be collected, the control device 21 closes the valves 12, 19, and 152 and opens the valve 13. This causes the exhaust gas from the incinerator 201 to flow through the horizontal portion 202H of the exhaust gas passage 202.

[0034] When collecting the incineration ash 205, the control device 21 first starts the compressor 154 to fill the air tank 153 with high-pressure gas. Next, the control device 21 starts the valve 12. 1 ,12 2 Open valve 13 1 ,13 2 As a result, the exhaust gas from the incinerator 201 flows through the bypass passage 11, and does not flow through the horizontal portion 202H of the exhaust gas passage 202.

[0035] Next, after opening the valve 19, the control device 21 opens and closes the multiple valves 152 provided on each injection nozzle 151 of the incineration ash removal mechanism 15 in sequence from the end side to the center side of the horizontal part 202H. As a modified example of the method of opening and closing the multiple valves 152, the multiple valves 152 may be opened in sequence from the end side to the center side of the horizontal part 202H, and finally all the valves 152 may be closed simultaneously. In addition, the multiple valves 152 may be opened and closed in sequence from the end side to the center side of the horizontal part 202H several at a time. As a result, the high-pressure gas injected from the injection nozzle 151 causes the incineration ash 205 accumulated on the inner surface of the horizontal part 202H to be peeled off in sequence from the end side and moved to the center side, and discharged from the discharge port 18 to the hopper 20.

[0036] Controller 21 then stops compressor 154, closes valve 19, and closes valve 12. 1 ,12 2 Close valve 13. 1 ,13 2 The trap is opened to complete the collection of the incineration ash 205.

[0037] The incineration ash 205 discharged to the hopper 20 is disposed of, for example, in a landfill after phosphorus components are recovered by a phosphorus separation device. The thermal energy extracted by the heat exchanger 203 is used, for example, to heat the air supplied to the incinerator 201 or to concentrate and dehydrate sludge separated and extracted from sewage.

[0038] As described above, according to the incineration facility 10, workers can collect the incineration ash 205 without entering the exhaust gas flow path 202. This eliminates the need to stop the incineration of the dewatered sludge 201P in the incinerator 201, solving the conventional problems of sewage treatment being delayed, the need for a huge amount of fuel to reheat the incinerator 201 leading to increased fuel costs, and increased environmental load.

[0039] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the control device 21 may be omitted and the valve 12 may be omitted. 1 ,12 2 ,13 1 ,13 2 , 152, 19 and the compressor 154 may be manually operated. 1 ,12 2 ,13 1 ,13 2 It is also possible to omit the bypass passage 11 and clean the exhaust gas passage 202 by spraying while the incinerator 201 is in operation.

[0040] The above-described embodiment has been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to having all of the configurations described. [Explanation of symbols]

[0041] 10 incineration equipment, 11 bypass flow path, 12 1 ,12 2 ...valves, 13 1 ,13 214... valve, 15... incineration ash removal mechanism, 151... injection nozzle, 152... valve, 153... air tank, 154... compressor, 18... discharge port, 19... valve, 20... hopper, 21... control device, 200... incineration equipment, 201... incinerator, 201P... dewatered sludge, 202... exhaust gas flow path, 202H... horizontal portion of exhaust gas flow path, 202V 1 ,202V 2 Vertical portion of exhaust gas flow path, 203 heat exchanger, 204 inspection hatch, 205 incineration ash

Claims

1. an incinerator for incinerating the dewatered sludge; an exhaust gas flow path for guiding exhaust gas generated by incineration of the dewatered sludge; An incineration ash removal mechanism that injects high-pressure gas onto the incineration ash accumulated on the inner surface of the exhaust gas flow path; Incineration facility equipped with:

2. The incineration facility according to claim 1, The exhaust gas flow path includes an outlet for discharging the incineration ash peeled off and moved by the incineration ash removal mechanism, The incineration ash removal mechanism includes: A plurality of injection nozzles at different distances from the discharge port are provided, The high-pressure gas is sprayed in sequence from the spray nozzle disposed farthest from the discharge port to the spray nozzle disposed closest to the discharge port. Incineration equipment.

3. The incineration facility according to claim 2, A first valve that controls the inflow of the exhaust gas to a portion of the exhaust gas flow path where the incineration ash removal mechanism is provided; A bypass flow path that guides the exhaust gas while the inflow of the exhaust gas to the portion of the exhaust gas flow path where the incineration ash removal mechanism is provided is regulated by the first valve; a second valve that controls an inflow of the exhaust gas from the exhaust gas flow path to the bypass flow path, The incineration ash removal mechanism operates with the first valve closed and the second valve open. Incineration equipment.

4. The incineration facility according to claim 3, A control device that controls at least one of the incineration ash removal mechanism, the first valve, and the second valve. Incineration equipment.

5. The incineration facility according to claim 3, a heat exchanger that transfers thermal energy contained in the exhaust gas to another heat medium, The exhaust gas passage and the bypass passage guide the exhaust gas to the heat exchanger. Incineration equipment.

6. The incineration facility according to claim 5, An inspection port for checking the incineration ash deposited on the inner surface of the exhaust gas flow path. Incineration equipment.

7. A method for removing incineration ash from an incineration facility, comprising the steps of: A plurality of injection nozzles are provided in an exhaust gas flow path for guiding exhaust gas generated by incineration of the dewatered sludge, A high pressure gas is injected from the plurality of injection nozzles. How to remove incineration ash.

Images