JP2021135009A - Waste incineration device and waste incineration method - Google Patents

Abstract

To provide a waste incineration device and a waste incineration method capable of enhancing stability in an amount of waste supplied to a fire grate and thereby contributing to stabilized incineration of the waste.SOLUTION: A waste incineration device comprises: a tube-like chute 4 downwardly extended from a hopper forming a waste supply port 3; and a receiving floor 5 which is positioned at a bottom section of the chute 4, is extended toward a fire grate 6 in an incineration furnace 2 and receives waste falling through the chute 4. The receiving floor 5 is divided into a plurality of receiving floor pieces 5a and 5b in at least a half area thereof from an intermediary position to a tip position thereof in a moving direction of the waste carried toward the fire grate 6 on the receiving floor 5. The plurality of receiving floor pieces 5a and 5b are a mixture of a movable receiving floor piece 5b and a fixed receiving floor piece 5a. The movable receiving floor piece 5b is connected to a drive device 14 so as to be reciprocated in a direction having a component identical with the moving direction of the waste.SELECTED DRAWING: Figure 1

Description

The present invention relates to a waste incinerator and a waste incinerator method.

As a waste incinerator for incinerating waste such as municipal waste, a grate-type incinerator that incinerates waste on a grate is known (Patent Document 1). In this grate-type incinerator, the waste put into the hopper falls onto the receiving floor through the inside of the tubular chute hanging from the hopper. A pusher is installed so that it can move back and forth toward the grate just above the floor. The pusher pushes out the waste that has fallen on the receiving floor and supplies it on the grate of the furnace body. The grate burns the waste that has fallen on the grate while transporting it.

Japanese Unexamined Patent Publication No. 2005-164121

The waste supplied to the waste incinerator has non-uniform properties such as moisture content, shape, dimensions, and compressibility. If the properties of the waste are not uniform, even if the waste that has fallen on the floor through the chute is pushed out with a pusher toward the grate, the waste will only be compacted by the push output of the pusher and will be placed on the grate. It may not be supplied. If the state where the waste is not supplied on the grate continues, the amount of waste burned in the furnace body becomes insufficient, which causes, for example, a decrease in the exhaust gas temperature and an increase in the CO concentration in the exhaust gas, and stable combustion is hindered. There is a problem of On the other hand, if the pusher is continued to operate in the above-mentioned state, at some point, the compacted waste will be agglomerated and fall onto the grate at once. In that case, the waste on the grate will be dropped. Since the amount increases rapidly and the combustion of waste starts at once after the completion of drying, it causes, for example, an increase in exhaust gas temperature, an increase in CO concentration in exhaust gas, an increase in NOx concentration, etc., and stable combustion is also hindered. There is. In addition, the burnout position on the grate may move to the ash drop port side, and there is a concern that the unburned portion in the ash will increase (increase in the amount of burning heat).

The present invention has been made in view of such a problem, and supplies the waste on the bed to the grate while loosening it to improve the quantitative supply of the waste to the incinerator body, thereby improving the quantitative supply of the waste. An object of the present invention is to provide a waste incinerator and a waste incineration method capable of contributing to stable combustion.

The above-mentioned problems are solved by the following waste incinerator and waste incinerator method according to the present invention.

<Waste incinerator>
It has a tubular chute that extends downward from the hopper that forms the waste inlet, and a floor that is located at the bottom of the chute, extends toward the grate in the combustion chamber, and receives the waste that falls in the chute. The floor is formed into a plurality of receiving pieces divided in a range from at least an intermediate position in the moving direction of the waste moving on the receiving floor toward the grate to the tip position of the receiving floor. The floor piece is formed by mixing a movable floor piece and a fixed floor piece, and the movable floor piece is connected to a drive device so as to reciprocate with a component in the moving direction. Waste incineration. Device.

In the present invention, it is preferable that the reciprocating direction of the movable floor receiving piece is inclined upward toward the front side in the moving direction.

In the present invention, it is preferable that the inner wall surface of the chute located on the floor receiving start end side in the moving direction of the waste on the floor has an inclined surface up to the floor receiving start end.

In the present invention, a control device is further provided, and the control device can control at least one of the drive timing, frequency, and speed of the drive device.

<Waste incinerator method>
It has a tubular chute that extends downward from the hopper that forms the waste inlet, and a bed that is located at the bottom of the chute, extends toward the grate in the incinerator, and receives the waste that falls in the chute. The bed is formed into a plurality of receiving pieces divided in a range from at least an intermediate position in the moving direction of the waste moving on the receiving bed toward the grate to the tip position of the receiving bed. The floor receiving piece is a waste incinerator in which a movable receiving piece and a fixed receiving piece are mixed and formed, and the movable receiving piece is connected to a driving device so as to reciprocate with a component in the moving direction. A waste incineration method in which the waste on the receiving floor that has fallen in the chute is moved toward the grate by the movable receiving piece.

According to the present invention, the waste on the incinerator is loosened by the movable incinerator and supplied to the grate to improve the quantitative supply of the waste to the incinerator body, which contributes to the stable combustion of the waste. It is possible to provide a waste incinerator and a waste incineration method capable of this.

It is a schematic block diagram of the waste incinerator as one Embodiment of this invention. It is an enlarged outline block diagram about the floor receiving as a main part in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The technical scope of the present invention is not limited to these embodiments, and can be implemented in various forms without changing the gist of the invention. Moreover, the technical scope of the present invention extends to an equal range.

First, the basic configuration and operation of the grate-type waste incinerator according to the embodiment of the present invention will be described.

FIG. 1 shows an outline configuration of a grate-type waste incinerator according to an embodiment of the present invention, and FIG. 2 shows an enlarged outline configuration of a bed receiving the grate type waste incinerator. In this embodiment, the upstream side (left side in FIG. 1) of the combustion chamber in the moving direction of waste in the combustion chamber (the direction of the furnace length extending to the left and right in FIG. 1) is referred to as a front portion, and the downstream side is referred to as a rear portion.

As seen in FIG. 1, the grate-type waste incinerator 1 (hereinafter referred to as “incinerator 1”) according to the present embodiment has a combustion chamber 2 and an upstream of the waste flow direction of the combustion chamber 2. A chute 4 arranged above the side (left side in FIG. 1) for throwing waste into the combustion chamber 2, a waste inlet 3 having an opening formed at the upper end of the chute 4, and waste in the combustion chamber 2. This is a grate-type waste incinerator equipped with a waste heat boiler (not shown) connected above the downstream side (right side in FIG. 1) in the flow direction of the above. At the lower end of the chute 4, a receiving floor 5 is provided to receive the waste that falls in the chute 4 after being thrown in from the waste throwing port 3. The inner wall surface 4a of the lower end portion of the chute 4 is inclined toward the start end (upstream end) position of the receiving floor 5, and is formed in a curved shape, for example.

In the receiving floor 5, a plurality of fixed receiving pieces 5a and movable receiving pieces 5b are arranged in a mixed manner from the upstream side to the downstream side, and are arranged alternately in the illustrated example. Such a bed 5 will be described in detail later again with reference to FIG.

As seen in FIG. 1, a grate (stalker) 6 for burning waste while moving it is provided at the bottom of the combustion chamber 2. The grate 6 is provided in the order of the dry grate 6a, the combustion grate 6b, and the post-combustion grate 6c from the side closer to the waste input port 3, that is, from the upstream side, and the dry grate 6a and the combustion fire are provided. A layer of waste W is formed on the lattice 6b. These grate 6a to 6c are interlocked by a grate drive mechanism (not shown) to transport waste forward and downstream.

In the dry grate 6a, waste is mainly dried and ignited. In the combustion grate 6b, the waste is mainly thermally decomposed and partially oxidized, and the combustible gas generated by the thermal decomposition and the solid content are burned to form a flame when the combustible gas burns. On the post-combustion grate 6c, the unburned solids in the remaining waste are completely burned. When the solid content in the waste burns, no flame is generated and it burns. The combustion ash after complete combustion is discharged from the ash discharge port 7.

A wind box 8 composed of wind boxes 8a, 8b, and 8c is provided below the dry grate 6a, the combustion grate 6b, and the post-combustion grate 6c in the combustion chamber 2, respectively. The combustion primary air P supplied by the blower 9 as the combustion primary air supply means described later is supplied to the air boxes 8a, 8b, 8c through the combustion primary air supply pipe 10, and is supplied to each of the grate 6a, It is supplied into the combustion chamber 2 through 6b and 6c. The combustion primary air P supplied from under the grate is used for drying and burning the waste on the grate 6a and 6b, as well as for cooling the grate 6a, 6b and 6c and stirring the waste. Has. The combustion primary air supply pipe 10 is provided with a primary air heating device 11 for heating the combustion primary air P and a damper 12 for adjusting the supply amount of the combustion primary air P.

A waste heat boiler (not shown) is continuously installed at the outlet on the downstream side of the combustion chamber 2, and the unburned portion (unburned) of the combustible gas in the gas discharged from the combustion chamber 2 is near the inlet of the waste heat boiler. It is a secondary combustion chamber 13 that burns gas). Secondary combustion gas is blown into the secondary combustion chamber 13 which is a part of the waste heat boiler, and the unburned gas is secondarily burned. After this secondary combustion, the combustion exhaust gas is recovered by the waste heat boiler. It generates steam and the steam is used in the generator. After the heat is recovered, the combustion exhaust gas discharged from the waste heat boiler is removed of acid gas by slaked lime, etc. in an exhaust gas treatment device system (not shown), and then sent to a dust remover (not shown), reaction products, dust, etc. Is recovered. The combustion exhaust gas after being detoxified by the dust removing device is attracted by an attraction fan (not shown) and discharged from the chimney into the atmosphere.

As seen in FIGS. 1 and 2, the receiving floor 5 has a plurality of plate-shaped fixed receiving floor pieces 5a and a plurality of movable receiving floor pieces 5b arranged in a mixed manner from the upstream side to the downstream side. In the illustrated example, they are arranged alternately. The adjacent fixed floor piece 5a and the movable floor piece 5b are inclined so as to form an upward slope from the upstream side to the downstream side, respectively, and a part of each of them overlaps and is parallel to each other. The movable floor receiving piece 5b is connected to a driving mechanism 14a driven by the driving device 14, and reciprocates in a direction Q parallel to the plate surface of the fixed floor receiving piece 5a under the operation of the driving mechanism 14a. Move. The direction of this reciprocating motion has components in the vertical direction and in the upstream and downstream directions. The drive device 14 is connected to the control device 15 and receives a command signal issued by the control device 15 based on information from a monitoring device (not shown) that monitors the combustion state of waste in the combustion chamber 2 and drives the drive device 14. At least one of timing, frequency, and speed is controlled.

As a preferred embodiment, the fixed floor piece 5a is provided with an air blowing portion 17-1 (see FIG. 2), and the air blowing portion 17-1 is directed upward in the direction Q and discarded on the movable floor receiving piece 5b. Air is blown out to the object W. The air from the air blowing portion 17-1 can be, for example, a part of the primary air P for combustion, and a part of the primary air P from the blower 9 is fixedly received through the pipe 17 provided with the damper 16. It is supplied to the air blowing portion 17-1 of the floor piece 5a. The opening / closing timing and opening degree of the damper 16 are adjusted by the control device 15.

As in the case of the drive device 14, the timing and amount of air blown out from the air blowout unit 17-1 are commands issued by the control device 15 based on information from a monitoring device (not shown) that monitors the combustion state of waste. It is controlled under the signal.

The air blowing portion 17-1 may be located on the fixed floor piece 5a, the movable floor piece 5b, or both. Further, the air blowing portion 17-1 may be formed as a hollow hole 17-2 inside these receiving pieces, or the bottom of the receiving piece in a form that does not hinder the relative movement between the receiving pieces. May be provided as a pipe portion. In the example of FIG. 2, the fixed floor piece 5a is formed as a hollow hole 17-2.

In the present embodiment, since the receiving floor 5 is divided into a plurality of receiving pieces 5a and 5b as described above, the amount of waste on each of the receiving pieces 5a and 5b Is also divided, so that it is possible to prevent the waste from agglomerating and to supply the waste in a stable manner. Further, since the floor receiving pieces 5a and 5b are arranged at an inclination as described above, it is possible to prevent the waste from rolling down under gravity. As a result, excessive combustion caused by a large amount of waste rolling down into the combustion chamber 2 under gravity is prevented, and the amount of waste accumulated in the chute 4 is kept constant to keep the amount of waste in the combustion chamber constant. It is possible to prevent the incineration smoke generated in No. 2 from flowing back into the chute 4.

Further, in the present embodiment, at least one of the driving timing, frequency, and speed of the driving device 14 for driving the movable bed piece 5b is controlled. However, as a situation in which such control is performed, for example, Examples include increasing and decreasing the driving speed according to the under and excessive incineration of waste in the combustion chamber 2, and reducing the driving speed at night when the amount of power generated by incineration of waste may be small.

Next, the procedure for incinerating waste in the incinerator 1 of the present embodiment will be described.

The waste W charged into the waste input port 3 reaches the receiving floor 5 via the chute 4 and is deposited on the receiving floor 5. Since the inner wall surface 4a at the lower end of the chute 4 has an inclined surface formed in a curved shape toward the start end of the receiving floor 5, the waste W at the lower end of the chute 4 is on the receiving floor 5 and starts from the receiving floor 5. It will not come off.

In the example of FIG. 1, in the example of FIG. 1, the fixed floor piece 5a and the movable floor piece 5b are alternately arranged, and the movable floor piece 5b is moved in the direction Q by the drive mechanism 14a operated by the drive device 14. It is moving back and forth. This direction Q has components in the vertical direction and in the upstream and downstream directions, and when the movable floor piece 5b moves upward and downstream, the waste W is in the form of a lump. Is also loosened by the movement of the movable floor piece 5b and transported toward the adjacent fixed floor piece 5a on the downstream side.

Thus, the waste W is then loosened again by the movable floor piece 5b located on the downstream side and transported further to the downstream side, and from the most downstream end (termination) of the floor 5, the first grate 6, that is, the drying It falls on the grate 6a. When a part of the primary air P for combustion is blown out from the receiving floor 5, for example, the air blowing portion 17-1 of the fixed receiving piece 5a, the waste conveyed on the receiving floor 5 by this blown air. Since the material W is loosened, the transportation of the waste W is further promoted.

The waste W that has fallen and accumulated on the dry grate 6a is placed on the combustion grate 6b and on the post-combustion grate 6c during the reciprocating motion of each grate 6a to 6c driven by a grate drive mechanism (not shown). A layer of waste W is formed on each of the grate 6a and 6b. The flow rate of the primary air P for combustion is controlled by the damper 12 from below the grate 6a and 6b, and is supplied via the air boxes 8a and 8b, whereby the waste on the grate 6a and 6b is dried. And it is burned. When the calorie (calorific value) of the waste is reduced, the air heated by the primary air heating device 11 is supplied. Further, the primary combustion air P is also supplied from below the post-combustion grate 6c through the air box 8c, which contributes to the combustion of the unburned residue of the waste on the post-combustion grate 6c.

The waste W is mainly dried and ignited on the dry grate 6a. That is, the waste on the dry grate 6a is dried in the upstream range of the dry grate 6a, ignites in the downstream range of the dry grate 6a, and reaches the upstream range (front) of the combustion grate 6b. Combustion starts in the range of. On the combustion grate 6b, the waste is mainly thermally decomposed and partially oxidized to generate a flammable gas, and the combustible gas is burned with a flame and the solid content in the waste is burned. Combustion of waste is substantially complete on the combustion grate 6b. On the post-combustion grate 6c, unburned components such as fixed carbon in the remaining waste are completely burned. In the region after the burn-off point, the solid unburned component (char) in the waste is burned, and the combustion ash after complete combustion is discharged from the ash discharge port 7.

As described above, waste heat boilers are continuously installed at the outlet of the combustion chamber 2, and the vicinity of the inlet of the waste heat boiler is the secondary combustion chamber 13. Therefore, the unburned gas generated in the combustion chamber 2 is guided to the secondary combustion chamber 13, where it is mixed and agitated with the secondary combustion air, and the secondary combustion is performed. After the secondary combustion, the exhaust gas is heat recovered by the waste heat boiler. After the heat is recovered, the exhaust gas discharged from the waste heat boiler is removed of acid gas by slaked lime or the like, and then sent to a dust remover (not shown) to recover reaction products, dust, and the like. After that, the exhaust gas after being detoxified by the dust removing device is attracted by an attracting fan (not shown) and discharged from the chimney into the atmosphere.

Further, as described above, the waste incinerator 1 is equipped with a monitoring device (not shown) for monitoring the combustion state of waste in the combustion chamber 2, and information on the combustion state is sent to the control device 15. Has been done. The control device 15 drives the movable floor piece 5b together with the supply amount of the primary air P for combustion and the transport speed of the grate 6 at the operation end, in FIG. 1, so as to maintain a good combustion state based on the received information. The drive timing, frequency, and speed of the drive device 14 are controlled, and the amount of primary air for combustion to the fixed floor piece 5a is controlled, and the amount of waste W supplied from the floor 5 to the grate 6 is controlled. To control. As a result, the quantitative supply of waste to the combustion chamber is ensured, and stable combustion of waste is realized.

In the present embodiment, the receiving floor 5 is provided with receiving floor pieces 5a and 5b in the entire moving direction of the waste, but it is discarded in consideration of stacking a certain amount of waste in the chute 4. It is also possible that the fixed floor piece and the movable floor piece are provided in a range from the intermediate position in the moving direction of the object to the position at the tip of the floor (the position on the most downstream side). As a result, a certain amount of waste is piled up in the chute 4, and the waste in the chute 4 can prevent smoke from leaking due to incineration.

The stable supply of waste is mentioned as an effect of this embodiment, but this is done by using a waste incinerator of the same type as the conventional waste incinerator disclosed in Patent Document 1 described above. It is based on a moving image actually captured by the inventor of the present application with a flame transmission camera. In this video, as described in paragraph [0004] of the present specification, it was confirmed that the supply of waste on the receiving floor located above the head wall was unstable. On the other hand, it was confirmed that the waste moving on the grate is moving stably. In this conventional waste incinerator, the grate is formed of grate pieces divided into a plurality of pieces. In the above video, every time the waste moving in the combustion chamber moves through the grate pieces. It was also confirmed that it was not agglomerated by moving up and down. As a result, the inventor found that the amount of waste movement depends on the size of the grate, and the amount of waste movement is constant because the grate is formed by the grate pieces divided into a plurality of pieces. I got the finding that it is. Therefore, in the present invention, a stable supply of waste into the combustion chamber is possible by installing a structure with reference to the above-mentioned grate having a plurality of divided grate pieces as a receiving floor on the upper part of the head wall. And said.

1 Waste incinerator (fire pot)
2 Combustion chamber 3 Waste inlet 4 Chute 4a (Chute's) inner wall surface 5 Receiving floor 5a Fixed floor receiving piece 5b Movable floor receiving piece 6 Grate 14 Drive device 15 Control device

Claims (5)

It has a tubular chute that extends downward from the hopper that forms the waste inlet, and a floor that is located at the bottom of the chute, extends toward the grate in the combustion chamber, and receives the waste that falls in the chute. The floor is formed into a plurality of receiving pieces divided in a range from at least an intermediate position in the moving direction of the waste moving on the receiving floor toward the grate to the tip position of the receiving floor. The floor receiving piece is formed by mixing a movable floor receiving piece and a fixed floor receiving piece, and is connected to a drive device so that the movable floor receiving piece reciprocates with a component in the moving direction. Incinerator. The waste incinerator according to claim 1, wherein the movable floor piece has a reciprocating direction that is inclined upward toward the front side in the moving direction. The chute according to claim 1 or 2, wherein the inner wall surface of the chute located on the floor receiving start end side in the moving direction of the waste on the floor receives an inclined surface up to the floor receiving start end. The listed waste incinerator. The waste incinerator according to claim 1, wherein the control device further includes a control device, and the control device controls at least one of the drive timing, frequency, and speed of the drive device. It has a tubular chute that extends downward from the hopper that forms the waste inlet, and a bed that is located at the bottom of the chute, extends toward the grate in the incinerator, and receives the waste that falls in the chute. The bed is formed into a plurality of receiving pieces divided in a range from at least an intermediate position in the moving direction of the waste moving on the receiving bed toward the grate to the tip position of the receiving bed. The floor receiving piece is a waste incinerator in which a movable receiving piece and a fixed receiving piece are mixed and formed, and the movable receiving piece is connected to a driving device so as to reciprocate with a component in the moving direction. A waste incineration method in which the waste on the receiving floor that has fallen in the chute is moved toward the grate by the movable receiving piece.

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