JP2010223473A - Nozzle cleaning device of stoker type incinerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide nozzle cleaning devices of a stoker type incinerator capable of washing away dust accumulated in nozzles, by providing cleaning devices, which supply water for cleaning inside the nozzles, for the nozzles installed in recirculation passages for blowing recirculation gas into a body of the incinerator. <P>SOLUTION: The stoker type incinerator is equipped with a dust collecting device for collecting/removing the dust contained in the recirculation gas, in the recirculation passages for recirculating a part of combustion exhaust gas in a combustion chamber above a stoker to which combusted objects are thrown, into the incinerator body by a fan as the recirculation gas. The nozzles 19, provided for the recirculation passages 17, 18 and blowing the recirculation gas into the incinerator body, are installed with the cleaning devices 93 for supplying the water for cleaning the dust which can not be captured by the dust collecting device 12 and is accumulated in the nozzles 19. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention provides a recirculation gas in a recirculation passage that recirculates a part of combustion exhaust gas in a combustion chamber above a stoker into which a combustible material such as waste and industrial waste is introduced as a recirculation gas into a furnace body by a fan. In a stoker-type combustion furnace equipped with a dust collector that collects and removes dust contained in the nozzle, the nozzle clogging is performed by cleaning the dust flowing out from the dust collector that accumulates in the nozzle that blows recirculated gas into the furnace body. The present invention relates to a nozzle cleaning device for a stoker-type incinerator that can prevent the above.

  The stoker-type incinerator is equipped with a stalker in which fixed-stage and movable-stage grates are alternately arranged, and the movable stage is reciprocated by a hydraulic device to agitate the waste (burned material) introduced from the hopper. While moving forward, the waste is dried in the drying zone located upstream of the stoker, and the main combustion is performed while introducing primary air in the next main combustion zone, and burns in the most downstream combustion zone. An incinerator configured to perform combustion every remaining portion.

The stoker-type incinerator of the technology provided in Patent Document 1 is provided with a recirculation passage that recirculates a part of the combustion exhaust gas in the combustion chamber above the stoker as recirculation gas into the furnace body by a fan. In addition, a dust collecting device is provided in the recirculation passage upstream of the fan to suppress fan and pipe wear and nozzle blockage.
In this stoker-type incinerator, primary air is introduced from below the stoker, and after performing primary combustion in the combustion chamber above the stoker, secondary combustion is performed in the upper part of the combustion chamber, and combustion exhaust gas in the combustion chamber A part is recirculated as a recirculation gas to the furnace body through a recirculation passage by a fan, and air is supplied to and mixed with the recirculation gas at the upstream portion of the fan in the recirculation passage. After removing dust and the like in the interior, the mixed gas is recirculated into the combustion chamber. As a result, unburned gas and unburned matter are completely burned, NOx is reduced, and the progress of corrosion of the fan is suppressed.

JP 2006-275502 A

    As described above, in the conventional stoker-type incinerator, the dust in the combustion exhaust gas is removed by the dust collector, and then the mixed gas is recirculated into the combustion chamber. Due to the limited capacity, it was difficult to completely remove dust. For this reason, there is a problem that dust gradually accumulates in the nozzle and the mixed gas cannot be sufficiently recirculated into the combustion chamber.

  The present invention solves the above-described problem, and a nozzle provided in the recirculation passage for blowing recirculation gas into the furnace body is provided with a cleaning device that supplies water for cleaning the inside of the nozzle, and accumulated in the nozzle. It aims at providing the nozzle cleaning apparatus of the stoker type incinerator which can wash away dust.

    In order to solve the above-mentioned problems, the present invention provides a recirculation gas in a recirculation passage for recirculating a part of the flue gas in the combustion chamber above the stoker into which the combusted material is introduced into the furnace main body as a recirculation gas. In a stoker-type combustion furnace equipped with a dust collector that collects and removes dust contained in the gas, the nozzle that is provided in the recirculation passage and blows recirculation gas into the furnace body cannot be captured by the dust collector. And a cleaning device for supplying water for cleaning the dust accumulated in the nozzle.

In the present invention, the cleaning device specifically has the following configuration.
In the cleaning device, a pipe is connected to a corner portion of the nozzle passage, and water is jetted along the nozzle wall surface through the pipe.
The pipe is connected obliquely along the nozzle wall surface so as to generate a swirling flow along the nozzle wall surface.
A combustion gas component measuring device and / or a furnace temperature measuring device is provided in the furnace body from either inside the furnace body or downstream of the furnace body, and an on-off valve for adjusting the amount of water based on the measuring device is provided. The purpose is to provide a high-pressure water supply pipe.

According to the present invention, water that cleans dust accumulated in the nozzle without being collected by the dust collector is supplied to the nozzle that is provided in the recirculation passage and blows the recirculation gas into the furnace body. Since the cleaning device is provided, dust accumulated in the nozzle can be washed away efficiently, so that clogging in the nozzle can be prevented and combustion exhaust gas can be efficiently recirculated. Since the water sprayed from the nozzle cleaning device is supplied into the incinerator together with the recirculated exhaust gas, it is possible to reduce NOx and suppress an excessive increase in the furnace temperature.
Further, according to the present invention, as a nozzle cleaning device, a pipe is connected to the nozzle passage, and the pipe is disposed along the nozzle wall surface, thereby supplying water so as to generate a swirling flow along the nozzle wall surface. Therefore, the inside of the nozzle can be washed away efficiently.
Further, according to the present invention, a combustion gas component measuring device and / or a furnace temperature measuring device is provided in any one of the furnace main body and downstream of the furnace main body. By providing an open / close valve for adjusting the amount in the water supply pipe, the amount of water can be adjusted according to the NOx, CO, O ₂ concentration in the combustion gas, and the furnace temperature.

It is a lineblock diagram of the nozzle cleaning device of the stoker type incinerator concerning a 1st embodiment of the present invention. It is a conceptual diagram which expands and shows the specific example of the nozzle cleaning apparatus provided in the nozzle channel | path which concerns on 2nd Embodiment of this invention. It is a block diagram of the nozzle cleaning apparatus of the stoker type incinerator which concerns on 3rd Embodiment of this invention.

[First Embodiment]
FIG. 1 is a configuration diagram of a nozzle cleaning device for a stoker-type incinerator according to the first embodiment of the present invention.
In FIG. 1, 1 is a waste hopper into which combustibles such as garbage and industrial waste are charged, and 2 is a stoker type incinerator. The stoker-type incinerator 2 includes a furnace body 2a that defines an outer shell, and a drying zone stoker 21 that mainly constitutes a drying zone, mainly a combustion zone, is provided at the bottom of the furnace at the inlet from the waste hopper 1. A main combustion zone stoker 22 and a vertical combustion zone stoker 23 which mainly constitutes a vertical combustion zone are arranged side by side. The dry zone stalker 21 is located on the most upstream side, the main combustion zone stalker 22 is located on the downstream side of the dry zone stalker 21, and the vertical combustion zone stalker 23 is located on the downstream side downstream of the main combustion zone stalker 22. Yes. Here, the main combustion zone refers to an area where a flame is raised on the dust layer and burned.

  Each of the stokers 21, 22, and 23 is provided with a moving grate disposed between fixed grate, and after putting in garbage (combustible material) by reciprocating movement of the moving grate, the garbage is put into the stalker 21. , And the main combustion is performed with the stoker 22, and finally the combustion is performed with the stoker 23. An ash collection tank 8 is provided below the vertical combustion zone stoker 23. In this embodiment, the number of the main combustion zone stokers 22 is three, but it is sufficient that one or a plurality of them are provided.

Further, a primary combustion chamber 3 is provided in the furnace body 2a above the stokers 21, 22, and 23, and a secondary combustion chamber 4 is further provided thereabove. Recirculating gas blowing nozzles 19a, 19b facing the secondary combustion chamber 4 are respectively installed on the side walls of the furnace body 2a. In this case, at least a pair of recirculation gas blowing nozzles 19a, 19b are installed on the side wall of the furnace body 2a, and preferably, a plurality of other recirculation gas blowing nozzles 19c, 19d can be installed on the side wall of the furnace body 2a. .
The recirculation gas blowing nozzles 19c and 19d are connected to the corresponding recirculation passages 17 and 18, respectively. The recirculation gas mixed with the primary air from the recirculation fan 13 is recirculated from the recirculation gas blowing nozzles 19a and 19b. It is made to eject into the secondary combustion chamber 4. In addition to the recirculation gas blowing nozzles 19a and 19b, the recirculation gas blowing nozzles 19c and 19d can also be ejected into the secondary combustion chamber 4 together. Further, a boiler 81 is connected to the exhaust gas outlet of the secondary combustion chamber 4. In addition, the recirculation gas blowing nozzle should just be provided at least 1 step | paragraph or more.

  The dry zone stalker 21, the combustion zone stalker 22 and the vertical combustion zone stalker 23 are provided with primary air pipes 51, 52 (three) and 53 which open to the lower wind boxes, respectively, from the primary air pipe. It is comprised so that air may be supplied. 6 is a primary air supply fan, and 5 is a primary air main pipe connecting the fan 6 and each of the primary air pipes 51, 52 (three), 53. The primary air pumped from the fan 6 is primary The air main pipe 5 is distributed to the primary air pipes 51, 52, 53. The primary air pipes 51, 52, 53 are provided with on-off valves 54, 55, 56 for opening and closing them, respectively. The primary air main pipe 5 is provided with an on-off valve 7 for opening and closing the primary air main pipe 5.

  A part of the combustion exhaust gas in the primary combustion chamber 3 (or in the secondary combustion chamber 4) may be extracted as a recirculation gas by the recirculation fan 13 on the side wall of the furnace body 2a located on the side of the vertical combustion zone stalker 23. A circulation gas extraction port 40 is provided, and the recirculation gas extracted from the recirculation gas extraction port 40 is introduced into the suction passage 12 a of the recirculation fan 13 through the recirculation passage 16 and the dust collector 12. It is like that.

  The dust collector 12 is provided at an upstream portion of the recirculation fan 13 in the recirculation passage 16, and the inlet passage 14 of the dust collector 12 is connected to the recirculation passage 16. Further, the outlet of the dust collector 12 and the inlet of the recirculation fan 13 are connected to each other via a suction passage 12a. Therefore, the recirculation gas outlet 40 and the suction passage 12a are connected via the recirculation passage 16, the inlet passage 14 and the dust collector 12, and the inlet of the recirculation fan 13 is opened and closed in the suction passage 12a. An opening / closing valve 013 is provided.

Further, a mixed air passage 30 branched from the primary air main pipe 5 at an upstream portion of the opening / closing valve 7 is connected to the inlet passage 14 of the dust collector 12, and the opening / closing valve for opening and closing the mixed air passage 30 is connected to the mixed air passage 30. When the opening / closing valve 30a is opened, the primary air from the primary air main pipe 5 is led to the inlet passage 14 and the dust collector 12 through the mixed air passage 30, and is recirculated through the suction passage 12a. A mixed gas, which is introduced into the inlet of the fan 13 and mixed with the recirculated gas and primary air, is introduced into the recirculating fan 13.
The on-off valve 7, the on-off valve 013, and the on-off valve 30a are controlled in opening / closing operation, opening degree, and the like by a control device (not shown). Thereby, the flow rate of the primary air flowing through the mixed air passage 30 is adjusted, or the mixing ratio of the combustion exhaust gas of the recirculation gas introduced into the recirculation fan 13 and the primary air is adjusted. .

Further, the recirculation gas after the primary air mixing pressure-fed by the recirculation fan 13 to the outlet-side recirculation passage 15 is sent to the recirculation gas blowing nozzles 19a to 19d through the downstream recirculation passages 17 and 18, respectively. The recirculation gas blowing nozzles 19a to 19d are jetted into the secondary combustion chamber 4. Further, an opening / closing valve 33 for opening and closing the recirculation passage 17 is provided, and an opening / closing valve 32 for opening and closing the recirculation passage 18 is provided.
In this embodiment, the primary air is mixed with the recirculation gas at the inlet of the recirculation fan 13 and introduced into the recirculation fan 13. However, the primary air is replaced with the primary air in the secondary combustion chamber 4. The secondary air to be ejected or the air from the outside may be mixed with the recirculation gas and introduced into the recirculation fan 13.

The stoker-type incinerator 2 is provided with a plant wastewater treatment facility 90 for treating boiler blow water or the like. From the plant waste water treatment facility 90, pipes 91 and 92 are laid toward recirculation gas blowing nozzles (also referred to as secondary air nozzles) 19a to 19d. When the recirculation gas blowing nozzles 19a and 19b are paired, the pipes 93a and 93b are directly connected to the ends of the pipes 91 and 92, and the pipes 93a and 93b are connected to the recirculation gas blowing nozzles 19a and 19b. .
In this embodiment, the ends of the pipes 91 and 92 are bifurcated, and pipes 93a, 93c, 93b, and 93d are connected to the branch passages as nozzle cleaning devices, respectively.
The plant wastewater treatment facility 90 is provided with a pump, and a part of the treated water such as boiler blow water is branched into the forks 91 and 92 and the ends of these branch pipes 91a, 91b, 92a and 92b. Pipes 93a, 93c, 93b, and 93d as nozzle cleaning devices provided are connected to the recirculation gas blowing nozzles 19a to 19d. Water is injected into the recirculation gas blowing nozzles 19a to 19d through these pipes 93a, 93c, 93b, and 93d. From the pipes 93a, 93c, 93b, 93d at the tips of the branch pipes 91a, 91b, 92a, 92b, the treated water of the plant wastewater treatment facility 90 is converted into water or high-pressure water (1 kg / cm ² (gauge)) depending on the pressure of the pump. Can be injected. Specifically, the nozzle cleaning device includes the pipes 93a, 93c, 93b, and 93d, a water supply tank for storing the treated water provided in the plant waste water treatment facility 90, and a pump that pumps the treated water. Yes.
When the recirculation gas blowing nozzles 19a and 19b are a pair, the pipes 91 and 92 may be directly connected to the pipes 93a and 93b as nozzle cleaning devices, so that the branch pipes 91a, 91b, 92a and 92b are connected. Can be omitted.

  Further, the treated water such as boiler blow water treated by the plant wastewater treatment equipment 90 is sent to the temperature reducing tower of the exhaust gas cooling equipment 94 for processing.

Next, the operation of the nozzle cleaning device for the stoker-type incinerator will be described.
During the start-up operation of the stoker-type incinerator 2, fuel and air are supplied into the primary combustion chamber 3 of the furnace body 2a, and the temperature in the furnace is raised in advance by burning the fuel with a burner or the like.
During steady operation, the combustible waste is introduced from the hopper 1, and the primary air passes from the fan 6 through the primary air main pipe 5 and the primary air pipes 51, 52, 53 to each stalker 21, 22, 23. The waste is combusted by the stokers 21, 22, and 23. Along with this, combustion exhaust gas is generated, and the generated combustion exhaust gas is led into the primary combustion chamber 3 and the secondary combustion chamber 4 above the stoker, and primary combustion and secondary combustion are performed. Part of the combustion exhaust gas in the primary combustion chamber 3 is extracted from the recirculation gas outlet 40 to the recirculation passage 16 as recirculation gas. This recirculation gas is mixed with the primary air for combustion supplied from the fan 6 to the inlet passage 14 through the primary air main pipe 5 and the mixed air passage 30, and then the dust collector 12, the recirculation fan 13, etc. The recirculation gas blowing nozzles 19a to 19d are respectively fed through the recirculation gas blowing nozzles 19a to 19d and recirculated by being blown into the secondary combustion chamber 4 from the recirculation gas blowing nozzles 19a to 19d.

  As described above, after the dust is removed by the dust collector 12, the recirculated gas is ejected from the recirculation gas blowing nozzles 19 a to 19 d into the secondary combustion chamber 4 by the recirculation fan 13. Thus, the dust cannot be completely removed, so that the recirculation gas is supplied to the recirculation gas blowing nozzles 19a to 19d in a state including the dust. For this reason, dust gradually accumulates in the recirculation gas blowing nozzles 19a to 19d. Therefore, when dust accumulates to some extent, the nozzle cleaning device is activated, and a part of the treated water such as boiler blow water treated by the plant waste water treatment facility 90 is supplied to the nozzle cleaning device as water for nozzle cleaning by a pump. Supply. Water pumped by the pump passes through the branch pipes 91a, 92b, the branch pipes 91a, 91b, 92a, 92b, and is injected into the recirculation gas blowing nozzles 19a-19d from the pipes 93a, 93c, 93b, 93d as nozzle cleaning devices. Is done. Thus, the dust in the recirculation gas blowing nozzles 19a to 19d is washed away by water, and the recirculation gas blowing nozzles 19a to 19d are prevented from being clogged. The water jetted into the secondary combustion chamber 4 together with the recirculated gas can reduce the NOx emission amount and suppress an excessive rise in the temperature in the furnace, and can prevent damage to the furnace such as a refractory material and a boiler tube. Since treated water generated from the plant wastewater treatment facility 90 can be used, the amount of plant wastewater can be reduced.

[Second Embodiment]
FIG. 2 shows a specific example of the nozzle cleaning device. In this case, three recirculation gas blowing nozzles 19 are provided in the recirculation passage 17 (18) for the recirculation gas.
These recirculation gas blowing nozzles 19 are bent pipes 17x (18x) bent at right angles to three branch pipes 17a, 17b, 17c (18a, 18b, 18c) branched from the recirculation passage 17 (18). The pipe 93 of the cleaning device is connected to the corner 17y (18y) of the bent pipe 17x (18x).

  The pipe 93 is connected to the bent corner portion 17y (18y) of the branch pipes 17a, 17b, 17c (18a, 18b, 18c) along the wall surface on the nozzle 19 side. It is installed to wash away the attached dust. Thereby, the water sprayed from the nozzle 19 can wash away dust efficiently along the inner wall surface. In this case, an angle of the pipe 93 is set obliquely along the wall surface on the nozzle 19 side, and the pipe is connected so as to supply water along the nozzle wall surface so as to generate a swirling flow along the nozzle wall surface. It is also possible to inject water obliquely along the inner wall surface 19 and supply it so as to generate a swirling flow. Thereby, dust can be washed away more efficiently.

[Third Embodiment]
FIG. 3 is a configuration diagram of a nozzle cleaning device for a stoker-type incinerator according to a third embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and description of the same parts is omitted.
In this embodiment, a NO measuring device, an O ₂ measuring device, and a CO measuring device are installed at the bag filter outlet or the like of the stoker-type incinerator 2, the measurement results of the measuring device 95 for these combustion gas components, and / or the furnace body A water supply valve 96 for supplying water to the pipe 93 of the cleaning device is installed in the water supply pipe based on the measurement result of the in-furnace temperature measuring device installed inside. The water supply valve 96 communicates with the recirculation gas blowing nozzles 19a to 19d and is provided in the branch pipes 91a, 91b, 92a, and 92b that serve as water supply pipes, respectively. The opening and closing of the water supply valve 96 is controlled by a control device 97 to which the measurement result of the combustion gas component measuring device 95 is inputted. The water supply valve 96 is opened and closed based on a command signal of the control device 97, and the pump The amount of water to be pumped by is controlled. The NO measuring device, the O ₂ measuring device, and the CO measuring device for measuring the combustion gas component are not limited to the bag filter outlet of the stoker type incinerator 2, but the chimney serving as the exhaust gas outlet downstream from the furnace body 2a. It can also be provided in the combustion gas path, such as between the outlets.

  In this case, the water supply valve 96 is opened / closed by an operation command of the control device 97 based on the measurement result of the measurement device 95 and / or the measurement result of the in-furnace temperature measurement device, and a predetermined amount of water is recirculated gas blowing nozzle. The dust accumulated in the recirculation gas blowing nozzles 19a to 19d can be washed away.

  According to each of the above embodiments, dust collected in the recirculation gas blowing nozzles 19a to 19d can be washed away using the treated water of the plant waste water treatment facility 90 that performs treatment such as boiler blow water. The clogging of the circulating gas blowing nozzles 19a to 19d can be prevented, and the recirculated gas can be circulated efficiently. The water jetted into the secondary combustion chamber 4 together with the recirculation gas can reduce the NOx emission amount and suppress an excessive increase in the temperature in the furnace, and can prevent damage to the furnace such as a refractory material and a boiler tube. Since the cleaning device can be operated to supply water to the pipe 93 based on the measurement result of the measuring device 95 and / or the measurement result of the temperature measuring device in the furnace, a certain amount of dust is generated when the cleaning device is stopped. When dust accumulates, dust can be washed away by the operation of the cleaning device. Since the controller 97 can control the opening and closing of the water supply valve 96, dust can be efficiently washed away with a minimum amount of treated water. Since the pipe 93 of the cleaning device is connected to the bent corner portion 17y (18y) of the branch pipes 17a, 17b, 17c (18a, 18b, 18c) provided with the recirculation gas blowing nozzle 19, the dust is efficiently washed away. I can do it.

  In addition, this invention is not limited only to the said embodiment, For example, it utilizes for flushing the dust collected in the recirculation gas blowing nozzles 19a-19d using the treated water of the plant waste water treatment equipment 90. However, if there is other available water, it may not be treated water of the plant wastewater treatment facility 90 in particular. Further, the recirculation gas blowing nozzle is more when the pair of recirculation gas blowing nozzles 19a and 19b is used or when the two-stage recirculation gas blowing nozzles 19a to 19d are used as described in the above embodiment. The present invention can also be applied to the case where the number of recirculation gas blowing nozzles is used. In this case, the recirculation gas piping may be shared, or may be supplied by individual piping. In addition, it goes without saying that the invention can be appropriately modified and changed without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Waste hopper 2 Stoker type incinerator 3 Primary combustion chamber 4 Secondary combustion chamber 5 Primary air main pipe 12 Dust collector 12a Intake passage 13 Recirculation fan 14 Inlet passage 15, 16, 17, 18 Recirculation passage 17a, 17b, 17c (18a, 18b, 18c) Branch pipe 17y (18y) Corner portion 19, 19a to 19d Recirculation gas outlet nozzle 21 Dry zone stalker 22 Main combustion zone stalker 23 Alternate combustion zone stalker 30 Mixed air passage 40 Recirculation gas outlet 90 Plant wastewater treatment equipment 91, 92 Piping 91a, 91b, 92a, 92b Branch pipe 93, 93a, 93c, 93b, 93d Pipe (nozzle cleaning device)

Claims (4)

  Dust collection that collects and removes dust contained in the recirculation gas in a recirculation passage that recirculates a part of the flue gas in the combustion chamber above the stoker into which the combustible material is introduced into the furnace body as a recirculation gas. In a stoker-type combustion furnace equipped with a device, the nozzle that is provided in the recirculation passage and blows recirculation gas into the furnace main body, and dust that has accumulated in the nozzle without being captured by the dust collector can be washed. A cleaning device for a stoker-type combustion furnace, comprising a cleaning device for supplying water.   The said cleaning apparatus connected the pipe to the corner | angular part of the said nozzle channel | path, and injected the water along the nozzle wall surface through this pipe, The cleaning apparatus of the stoker type combustion furnace of Claim 1 characterized by the above-mentioned.   The cleaning device for a stoker-type combustion furnace according to claim 1 or 2, wherein the pipe is connected obliquely along the nozzle wall surface so as to generate a swirling flow along the nozzle wall surface.   A combustion gas component measuring device and / or a furnace temperature measuring device is provided in the furnace body from either inside the furnace body or downstream of the furnace body, and an on-off valve for adjusting the amount of water based on the measuring device is provided. The cleaning device for a stoker-type combustion furnace according to any one of claims 1 to 3, wherein the cleaning device is provided in a water supply pipe.

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