JP6797084B2 - Gas supply method for secondary combustion, gas supply structure for secondary combustion, and waste incinerator - Google Patents

Description

The present invention mainly relates to a method for appropriately supplying a gas for secondary combustion used in secondary combustion.

Conventionally, a waste incinerator that performs primary combustion and secondary combustion that burns primary combustion gas including unburned gas generated in primary combustion in a combustion chamber has been known. Patent Documents 1 to 3 disclose techniques for supplying a gas for secondary combustion.

Patent Document 1 provides oxygen-enriched air (or normal air) from one furnace wall to the combustion chamber as a secondary combustion gas, and supplies recirculated exhaust gas from the other furnace wall to the combustion chamber. Disclosed is an incinerator having a structure that improves the mixing of the secondary combustion gas and the unburned component (unburned gas) of the primary combustion.

Patent Document 2 discloses an incinerator having a configuration in which a mixed gas having an adjusted mixing ratio is generated by adjusting the flow rates of the secondary air and the returned exhaust gas, and the mixed gas is supplied to the combustion chamber.

In Patent Document 3, a nozzle is arranged inside a secondary air supply pipe that supplies secondary air, and compressed air is blown from this nozzle to create an unburned component (unburned gas) of the secondary air and combustible gas. Disclose an incinerator having a configuration that improves the mixing of the above. In Patent Document 3, the gases supplied from the nozzles are secondary air and compressed air, both of which are air, and are therefore considered to be the same type of secondary combustion gas.

Japanese Unexamined Patent Publication No. 2001-241629 JP-A-2015-55385 Japanese Unexamined Patent Publication No. 4-55609

However, in Patent Document 1, since oxygen-enriched air (or normal air) and recirculated exhaust gas are supplied to the combustion chamber from different locations, for example, when the supply amount of one of the secondary combustion gases is reduced, this Since the reach of the secondary combustion gas is limited, the secondary combustion gas and the unburned component of the primary combustion are not sufficiently mixed. Further, since it is necessary to supply the two types of secondary combustion gases from individual supply points, a large number of supply points are required. Further, in Patent Document 2, the secondary air and the returned exhaust gas are mixed in advance and then supplied to the combustion chamber, but in this method, the mixed gas and the unburned gas in the combustion chamber may not be sufficiently mixed. It was sexual and improvement was desired. Further, Patent Document 3 requires an air compressor for generating compressed air, and the power consumption is significantly increased in order to operate the air compressor. Further, Patent Document 3 does not describe a configuration in which both secondary air and circulated exhaust gas are supplied to the combustion chamber.

The present invention has been made in view of the above circumstances, and a main object thereof is to sufficiently mix a primary combustion gas containing an unburned gas and a secondary combustion gas while suppressing power consumption. The purpose is to provide a gas supply method for secondary combustion.

The problem to be solved by the present invention is as described above, and next, the means for solving this problem and its effect will be described.

From the viewpoint of the present invention, the following gas supply method for secondary combustion is provided. That is, this gas supply method for secondary combustion is performed on a waste incinerator in which primary combustion and secondary combustion for burning primary combustion gas including unburned gas generated in the primary combustion are performed in a combustion chamber. Will be. The secondary combustion gas supply method is a gas containing oxygen used in the secondary combustion, and is a secondary combustion gas that is one of three types: secondary air, circulating exhaust gas, and a mixed gas thereof. Includes supply process. In the supply step, the secondary combustion gas is supplied to the combustion chamber so that an inner space and an outer space are formed. When viewed in the flow direction of the secondary combustion gas, the inner space is a space through which the secondary combustion gas flows, and the outer space is located outside the inner space and also covers the inner space. It is a space surrounded by a space through which a gas for secondary combustion different from the gas for secondary combustion flowing in the inner space flows. The inner space and the control device of the waste incinerator to different combinations of secondary combustion gas flowing through said outer space is changed according to the situation.

As a result, for example, even if the supply amount of the secondary combustion gas in one of the inner space and the outer space is reduced, the supply amount as a whole is not significantly reduced, so that the secondary combustion gas is primarily burned. Can be mixed well with gas. Further, since two types (or different mixing ratios) of secondary combustion gas can be supplied at one location, the number of gas supply locations provided in the incinerator can be reduced. Also, unlike the case where two types of secondary combustion gas are mixed in advance, the secondary combustion gas in the inner space and the secondary combustion gas in the outer space are supplied separately at the same time, so the flow in the combustion chamber In the above, a vortex effect is generated by contact of different gases at the flow interface of the two types of secondary combustion gases, and this vortex effect causes the two types of secondary combustion gases as a whole to be combined with the primary combustion gas in the combustion chamber. Since the stirring / diffusing effect can be more exerted, the secondary combustion gas and the primary combustion gas can be sufficiently mixed. Further, since an air compressor that generates compressed air for accelerating the secondary combustion gas is not required, the power consumption can be suppressed.

According to the present invention, it is possible to provide a method for supplying a secondary combustion gas for sufficiently mixing a primary combustion gas containing an unburned gas and a secondary combustion gas while suppressing power consumption.

The schematic block diagram of the incinerator of one Embodiment of this invention. Functional block diagram of the incinerator. The cross-sectional view which shows the gas supply structure for secondary combustion. The table which shows the example of the combination of the secondary combustion gas A and the secondary combustion gas B. The figure which shows the state which the secondary combustion gas and the primary combustion gas come into contact with each other in a combustion chamber.

First, the incinerator (waste incinerator) 10 of the present embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of an incinerator 10 according to an embodiment of the present invention. In the following description, when the terms "upstream" and "downstream" are used, they mean upstream and downstream in the direction in which waste, combustion gas, combustion gas, exhaust gas, etc. flow.

The present invention is applicable to incinerators having various configurations. Therefore, for example, the incinerator 10 may be a grate type incinerator, a fluidized bed type incinerator, or a fixed bed type incinerator.

The incinerator 10 includes a combustion chamber 20 and a gas supply device 50. First, the combustion chamber 20 will be described. A primary combustion zone 11 and a secondary combustion zone 12 are formed in the combustion chamber 20. Hereinafter, the primary combustion performed in the primary combustion zone 11 and the secondary combustion performed in the secondary combustion zone 12 will be described.

<Primary combustion and secondary combustion> The primary combustion zone 11 is a space for primary combustion. The primary combustion is to react the input waste with a gas for primary combustion and burn it (drying, flame combustion, oki combustion). The primary combustion gas is a gas containing oxygen supplied for the primary combustion. The primary combustion gas includes primary air, circulating exhaust gas, and a mixed gas thereof. The primary air is air taken in from the outside and is not used for combustion or the like (that is, excluding circulating exhaust gas). Therefore, the primary air also includes a gas obtained by heating the air taken in from the outside. Further, the primary combustion generates a primary combustion gas (flue gas after primary combustion) containing an unburned gas such as CO.

The primary combustion will be further described. For example, assume that the incinerator 10 is a grate type incinerator and is composed of a drying stage, a combustion stage, and a post-combustion stage. In this case, in the drying stage, the waste is dried and pyrolysis gas is generated. In the combustion stage, the waste dried in the drying stage mainly causes flame combustion, and ash, solid unburned matter that could not be completely burned, and primary combustion gas including unburned gas are mainly generated. Further, in the post-combustion stage, solid unburned material that could not be completely burned in the combustion stage is burned to the brim, and ash and primary combustion gas including unburned gas are mainly generated. Here, in the drying stage, the combustion stage, and the post-combustion stage, the waste is dried, flame-burned, and burned to generate primary combustion gas, so that primary combustion is performed. As described above, since the present invention can be applied to incinerators having various configurations, the incinerator 10 may have a configuration in which at least one of a drying stage and a post-combustion stage does not exist, or each configuration may be present. The structure may be such that the steps are not clearly divided.

The secondary combustion zone 12 is a space for secondary combustion. The secondary combustion is to react the unburned gas contained in the primary combustion gas with the secondary combustion gas and burn it. The gas for secondary combustion is a gas containing oxygen supplied for secondary combustion. The secondary combustion gas includes secondary air, circulating exhaust gas, and a mixed gas thereof. The secondary air is air taken in from the outside and is not used for combustion or the like (that is, excluding circulating exhaust gas). Therefore, the secondary air also includes a gas obtained by heating the air taken in from the outside. Combustion completeness can be promoted by performing secondary combustion.

Further, in FIG. 1, the secondary combustion zone 12 is formed directly above the primary combustion zone 11, but if it is a space to which the primary combustion gas is supplied, secondary combustion other than directly above the primary combustion zone 11 Zone 12 may be formed. Further, for example, the incinerator may be configured to burn the unburned gas contained in the primary combustion gas in a plurality of times by supplying the secondary combustion gas on the upstream side and the downstream side. Even in this case, considering the above definition of secondary combustion, all of the multiple combustions correspond to secondary combustion.

<Supply of primary combustion gas and secondary combustion gas> The gas supply device 50 is a device that supplies gas (primary combustion gas, secondary combustion gas) into the combustion chamber 20. The gas supply device 50 of the present embodiment includes a primary air supply unit 51, a secondary air supply unit 52, and an exhaust gas supply unit 53. Each supply unit is composed of a blower for attracting or sending out gas. Since each supply unit (blower) is intended to move gas, it is different from a compressor intended to compress gas.

The primary air supply unit 51 supplies the primary air to the combustion chamber 20 via the primary supply path 71. A first damper 81 is provided in the primary supply path 71, and the amount of primary air supplied to the combustion chamber 20 can be adjusted. As shown in FIG. 2, the first damper 81 is controlled by the control device 90.

Further, a heater may be provided in the primary supply path 71 so that the temperature of the primary air supplied to the combustion chamber 20 can be adjusted. Further, as described above, since the primary combustion gas also includes the circulating exhaust gas and the mixed gas, they may be supplied to the combustion chamber 20. Further, in the present embodiment, the gas for primary combustion is supplied to the primary combustion zone 11 from below, but may be supplied from the side of the primary combustion zone 11 or the like. Further, the gas for primary combustion may be supplied to the upstream side of the primary combustion zone 11 if it is used for primary combustion.

The secondary air supply unit 52 supplies secondary air (secondary combustion gas) to the combustion chamber 20 via the upstream secondary supply path 72 and / or the downstream secondary supply path 73. The exhaust gas supply unit 53 supplies the circulating exhaust gas (secondary combustion gas) to the combustion chamber 20 via the upstream secondary supply path 72 and / or the downstream secondary supply path 73.

More specifically, a second damper 82 is provided in the path connecting the secondary air supply unit 52 and the upstream secondary supply path 72, and the upstream side two is provided according to the control of the control device 90. The amount of secondary air supplied to the secondary supply path 72 can be adjusted. Further, a third damper 83 is provided in the path connecting the exhaust gas supply unit 53 and the upstream secondary supply path 72, and supplies the exhaust gas to the upstream secondary supply path 72 according to the control of the control device 90. The amount of circulating exhaust gas supplied can be adjusted. With this configuration, it is possible to control the supply amount of the secondary air supplied from the upstream secondary supply path 72, the supply amount of the circulating exhaust gas, and their ratios.

Similarly, a fourth damper 84 is provided in the path connecting the secondary air supply section 52 and the downstream secondary supply path 73, and connects the exhaust gas supply section 53 and the downstream secondary supply path 73. A fifth damper 85 is provided on the path to be used. With this configuration, the supply amount of the secondary air supplied from the downstream secondary supply path 73, the supply amount of the circulating exhaust gas, and their ratio can be controlled according to the control of the control device 90. Further, the adjusting unit 80 is composed of the second damper 82 to the fifth damper 85. Therefore, the adjusting unit 80 can adjust the type (secondary air, circulating exhaust gas, or mixed gas) and the amount of the secondary combustion gas supplied through the plurality of paths.

In the present embodiment, the secondary combustion gas is supplied to the secondary combustion zone 12. However, if the gas for secondary combustion is used for secondary combustion, it may be supplied to the upstream side (for example, the primary combustion zone 11) of the secondary combustion zone 12.

In the present embodiment, the secondary combustion gas is supplied separately to the upstream side and the downstream side, but the secondary combustion gas may be supplied from only one of them. Further, in the present embodiment, the secondary combustion gas is supplied from each of the upstream side and the downstream side, but the secondary combustion gas may be supplied from a plurality of locations, respectively. Further, in the present embodiment, both the secondary air and the circulating exhaust gas can be supplied on both the upstream side and the downstream side, but only the secondary air or the circulating exhaust gas is provided on only one of the upstream side and the downstream side. May be supplied.

<Electrical configuration and automatic combustion control> As shown in FIGS. 1 and 2, the incinerator 10 is provided with a plurality of sensors for grasping the combustion state and the like. Specifically, the incinerator 10 is provided with a combustion chamber gas temperature sensor (combustion sensor) 91, a CO gas concentration sensor (combustion sensor) 92, and a NOx gas concentration sensor (combustion sensor) 93. ..

The combustion chamber gas temperature sensor 91 is arranged in the combustion chamber 20, detects the combustion chamber gas temperature which is the gas temperature in the combustion chamber 20, and outputs the gas temperature to the control device 90. A plurality of combustion chamber gas temperature sensors 91 may be provided at different positions in the gas flow direction. In this case, since the combustion chamber gas temperature on the upstream side and the combustion chamber gas temperature on the downstream side can be obtained individually, the combustion state can be estimated more accurately. Further, a plurality of combustion chamber gas temperature sensors 91 may be provided at the same position in the gas flow direction (for example, one side wall and the other side wall at the same height). In this case, since the temperature at the same position in the gas flow direction can be measured more accurately, the combustion state can be estimated more accurately.

The CO gas concentration sensor 92 is located downstream of the combustion chamber 20 and further downstream than the dust collector shown in the figure, and detects the CO gas concentration contained in the exhaust gas (CO gas concentration discharged from the incinerator). Output to the control device 90. From the CO gas concentration discharged from the incinerator detected by the CO gas concentration sensor 92, although it was reacted with the secondary combustion gas by the secondary combustion in the combustion chamber 20, a sufficient contact reaction with the secondary combustion gas was not made. As a result, the concentration of CO (how much unburned gas is generated), which is the unburned gas remaining in the combustion gas (secondary combustion gas) discharged from the outlet of the combustion chamber 20, is grasped. be able to.

Like the CO gas concentration sensor 92, the NOx gas concentration sensor 93 is arranged further downstream than the dust collector, and detects the NOx gas concentration (NOx gas concentration discharged from the incinerator) contained in the exhaust gas to control the control device 90. Output to. From the NOx gas concentration discharged from the incinerator detected by the NOx gas concentration sensor 93, the difference between the concentration of NOx gas discharged from the combustion chamber 20 and the target NOx gas concentration can be grasped.

The control device 90 is composed of a CPU, RAM, ROM, etc., performs various calculations, and controls the entire incinerator 10. Hereinafter, among the controls performed by the control device 90, automatic combustion control will be described.

The automatic combustion control is to comprehensively judge the combustion data (internal detection data) of the incinerator 10 obtained from the above-mentioned plurality of sensors and to maintain the combustion state of the combustion chamber 20 stably for a long period of time. Is the control of. Specifically, as shown in FIG. 2, the control device 90 adjusts the supply amount of the gas supplied to each part by adjusting the first damper 81 to the fifth damper 85. Further, the control items other than the gas supply amount may be adjusted.

By making such adjustments, the combustion state of the combustion chamber 20 can be stably maintained for a long period of time. Further, the combustion generated in the incinerator 10 greatly differs depending on the shape and structure of the incinerator 10 and the waste to be charged. In addition, the target value for automatic combustion control also differs greatly depending on the durability of the incinerator 10, the required processing amount, the laws and regulations regarding exhaust gas, and the like. The control device 90 comprehensively determines them and performs automatic combustion control.

For example, when the combustion chamber gas temperature detected by the combustion chamber gas temperature sensor 91 is low, it is highly possible that the combustion in the combustion chamber 20 is insufficient, so that it is included in the primary combustion gas and / or the secondary combustion gas. Control may be performed to increase the amount of oxygen supplied (increase the supply amount or increase the air supply ratio). Further, for example, when the CO gas concentration discharged from the incinerator detected by the CO gas concentration sensor 92 is high, there is a high possibility that the secondary combustion is insufficient, so that the amount of oxygen contained in the secondary combustion gas is increased (supply amount). (Or increase the air supply ratio) control may be performed. Further, for example, when the NOx gas concentration discharged from the incinerator detected by the NOx gas concentration sensor 93 is high, control may be performed to increase the supply amount or the supply ratio of the circulating exhaust gas in order to reduce the concentration. The control shown above may not be performed depending on the values of other in-core detection data.

<Specific Supply Structure of Secondary Combustion Gas> Next, the secondary combustion gas supply structure 30 which is a structure for supplying the secondary combustion gas to the combustion chamber 20 will be described with reference to FIG. .. FIG. 3A is a cross-sectional view showing a gas supply structure 30 for secondary combustion. FIG. 3B is a view of the secondary combustion gas supply structure 30 in the flow direction of the secondary combustion gas (cross-sectional view taken along the line AA of FIG. 3A).

In the present embodiment, the secondary combustion gas is supplied from two locations, the upstream side secondary supply path 72 and the downstream side secondary supply path 73, both of which have the same structure as the secondary combustion gas supply structure 30. Is adopted. The gas supply structure 30 for secondary combustion includes an inner pipe 31, an outer pipe 32, a first relay pipe 33, and a second relay pipe 34.

As shown in FIGS. 3A and 3B, the inner pipe 31 and the outer pipe 32 have a double pipe structure. That is, the outer pipe 32 is arranged outside the inner pipe 31 so as to surround the inner pipe 31. In the present embodiment, the inner pipe 31 and the outer pipe 32 are both cylindrical and have the same position of the central axis, but at least one of the inner pipe 31 and the outer pipe 32 may be other than the cylinder, and the position of the central shaft may be different. May differ to some extent. Further, the downstream end of the inner pipe 31 is positioned on the same surface as the inner surface of the wall portion 20a of the combustion chamber 20, but the flow shape of the secondary combustion gas inside the secondary combustion zone 12 is optimized. Therefore, the downstream end of the inner pipe 31 may be a position retracted toward the outside of the furnace or a position protruding toward the inside of the furnace from the same surface position as the inner surface of the wall portion 20a.

A hole is formed in the wall portion 20a of the combustion chamber 20, and an outer pipe 32 is attached to this hole. Similarly, the inner pipe 31 also passes through a hole formed in the wall portion 20a. With this configuration, the secondary combustion gas can be supplied to the combustion chamber 20 from both the inner pipe 31 and the outer pipe 32. Although the outer pipe 32 is attached vertically to the wall portion 20a, it may be attached at an angle.

A first relay pipe 33 is connected to the outer peripheral surface of the inner pipe 31. The secondary air supplied by the secondary air supply unit 52 flows through the first relay pipe 33. With this configuration, secondary air is supplied to the inner pipe 31. The first relay pipe 33 may be connected to a surface other than the outer peripheral surface of the inner pipe 31. Further, the inner pipe 31 is located at the upstream end portion on the outer side in the axial direction of the outer pipe 32, and the first relay pipe 33 is connected to this portion. The first relay pipe 33 may be connected to a portion of the inner pipe 31 located inside the outer pipe 32.

A second relay pipe 34 is connected to the outer peripheral surface of the outer pipe 32. Circulated exhaust gas supplied by the exhaust gas supply unit 53 flows through the second relay pipe 34. With this configuration, the circulating exhaust gas is supplied to the outer pipe 32. The second relay pipe 34 may be connected to a surface other than the outer peripheral surface of the outer pipe 32.

In the present embodiment, the secondary air is supplied from the inner pipe 31 to the combustion chamber 20, and the circulating exhaust gas is supplied from the outer pipe 32 to the combustion chamber 20. Further, by performing the above-mentioned automatic combustion control, the supply amount of the secondary air and the circulating exhaust gas and the supply ratio thereof are adjusted.

The secondary combustion gas supplied from the inner pipe 31 and the outer pipe 32 is not limited to the above. Hereinafter, a specific description will be given. In the following description, the secondary combustion gas supplied from the inner pipe 31 is referred to as the secondary combustion gas A, and the secondary combustion gas supplied from the outer pipe 32 is referred to as the secondary combustion gas B.

Examples of combinations of secondary combustion gases are shown in the table of FIG. FIG. 4 is a table showing an example of a combination of the secondary combustion gas A supplied from the inner pipe 31 and the secondary combustion gas B supplied from the outer pipe 32. As described above, there are three types of secondary combustion gases: secondary air, circulating exhaust gas, and a mixed gas thereof. Further, the mixed gas can have different mixing ratios. Here, the secondary combustion gas A and the secondary combustion gas B are defined so as to have different types or mixing ratios. Based on the above, as shown in the table of FIG. 4, seven combinations can be considered. The types of the first to sixth combinations are different between the secondary combustion gas A and the secondary combustion gas B. The seventh combination has a different mixing ratio.

In order to supply the mixed gas as the secondary combustion gas A or the secondary combustion gas B, the secondary air supply path and the circulating exhaust gas are on the upstream side of the first relay pipe 33 or the second relay pipe 34. It is necessary that the supply route of is merged. Further, in order to adjust the mixing ratio, a damper or the like is required for each supply path.

Further, the incinerator 10 may have a configuration in which one of the combinations shown in FIG. 4 is always adopted, or a configuration in which the combination is changed depending on the situation. In the latter configuration, the number of dampers and the like increases and the control becomes more complicated than in the former configuration, but since the number of control items can be increased, there is a possibility that the combustion state can be controlled better.

Further, when the incinerator 10 has a plurality of secondary combustion gas supply structures 30, the same combination may be adopted for all of them, or different combinations may be adopted for at least one of them.

Further, the secondary combustion gas supply structure 30 can supply the secondary combustion gas so as to be sufficiently mixed with the primary combustion gas by the above configuration. The details will be described below. The secondary combustion gas supply structure 30 has a double-tube structure and supplies the secondary combustion gas A and the secondary combustion gas B. Therefore, as shown in FIG. 5, when viewed in the flow direction of the secondary combustion gas, it is located outside the inner space where the secondary combustion gas A flows and the inner space and surrounds the inner space. The secondary combustion gas is formed in the combustion chamber so that the secondary combustion gas B flowing in a different type or mixing ratio from the secondary combustion gas A flowing in the inner space is formed. It is supplied to 20.

As a result, even if the supply amount of the secondary combustion gas A or the secondary combustion gas B is reduced by automatic combustion control or the like, the supply amount as a whole is not significantly reduced. Therefore, since the reach of the secondary combustion gas is not so narrow, the secondary combustion gas can be sufficiently mixed with the primary combustion gas. Further, since the secondary combustion gas supply structure 30 can supply two types of secondary combustion gases having different types or mixing ratios, the number of secondary combustion gas supply structures 30 can be reduced. Alternatively, from another point of view, since it is possible to supply two types of secondary combustion gas without increasing the number of secondary combustion gas supply structures 30, the number of control items (control targets) for automatic combustion control increases. It may be easier to achieve a more appropriate combustion situation.

Further, the method of the present embodiment can exert a higher effect than the configuration in which two kinds of secondary combustion gases are mixed in advance and supplied to the combustion chamber. That is, since the secondary combustion gas A in the inner space and the secondary combustion gas B in the outer space are supplied individually at the same time, two types of secondary combustion gases A and B are supplied in the flow in the combustion chamber. A vortex effect is generated by the contact of different gases at the flow interface of the two types of gases, and the effect of stirring and diffusing the two types of secondary combustion gases as a whole with the primary combustion gas in the combustion chamber can be further exerted. .. Due to this stirring / diffusing effect, the primary combustion gas and the secondary combustion gas are easily mixed.

Therefore, by supplying the combustion chamber 20 with a double layer of the secondary combustion gas A and the secondary combustion gas B having different types or mixing ratios, the primary combustion gas and the secondary combustion gas are used without using compressed air. The gas can be mixed well. Therefore, the air compressor is not required, and the power consumption for operating the air compressor is also unnecessary. Therefore, the in-pipe speed does not differ significantly between the secondary combustion gas A and the secondary combustion gas B (for example, the ratio of the in-pipe velocities is less than 5).

As described above, in the present embodiment, since the primary combustion gas and the secondary combustion gas are sufficiently mixed, the combustion completeness can be promoted. In particular, in the present embodiment, since the above-mentioned automatic combustion control is performed, the combustion completeness can be further promoted.

As described above, the method for supplying the gas for secondary combustion of the present embodiment is performed on the incinerator 10 in which the primary combustion and the secondary combustion are performed in the combustion chamber 20. The method for supplying a gas for secondary combustion includes a supply step of supplying a gas for secondary combustion, which is a gas containing oxygen used in secondary combustion. In the supply process, the secondary combustion gas is supplied to the combustion chamber 20 so that the inner space and the outer space are formed. When viewed in the flow direction of the secondary combustion gas, the inner space is the space through which the secondary combustion gas flows, and the outer space is located outside the inner space and surrounds the inner space. , A space in which a secondary combustion gas of a different type or mixing ratio than the secondary combustion gas flowing in the inner space flows.

As a result, as described above, the primary combustion gas and the secondary combustion gas can be sufficiently mixed, so that the completion of combustion can be promoted.

Although the preferred embodiment of the present invention has been described above, the above configuration can be changed as follows, for example.

In the above embodiment, the combustion chamber gas temperature sensor 91, the CO gas concentration sensor 92, and the NOx gas concentration sensor 93 have been described as combustion sensors, but automatic combustion control is performed using any one of the combustion sensors. Alternatively, automatic combustion control may be performed by adding a combustion sensor other than the above.

10 Incinerator (waste incinerator)
20 Combustion chamber 30 Gas supply structure for secondary combustion 31 Inner pipe 32 Outer pipe 33 1st relay pipe 34 2nd relay pipe 72 Upstream side secondary supply route 73 Downstream side secondary supply route 80 Coordinator 90 Control device 91 Combustion chamber Gas temperature sensor (combustion sensor)
92 CO gas concentration sensor (combustion sensor)
93 NOx gas concentration sensor (combustion sensor)

Claims (4)

For a waste incinerator that performs primary combustion and secondary combustion that burns primary combustion gas including unburned gas generated in primary combustion in the combustion chamber, it is a gas containing oxygen used in secondary combustion. Therefore, in a secondary combustion gas supply method including a supply step of supplying a secondary combustion gas, which is one of three types of secondary air, circulating exhaust gas, and a mixed gas thereof.
In the supply process, when viewed in the flow direction of the secondary combustion gas,
The inner space where the gas for secondary combustion flows and
An outer space that is located outside the inner space and surrounds the inner space, through which a gas for secondary combustion different from the gas for secondary combustion flowing through the inner space flows.
The gas for secondary combustion is supplied to the combustion chamber so as to be formed.
A method for supplying a gas for secondary combustion , wherein the control device of the waste incinerator changes the combination of types of the gas for secondary combustion flowing through the inner space and the outer space according to a situation. For a waste incinerator that performs primary combustion and secondary combustion that burns primary combustion gas including unburned gas generated in primary combustion in the combustion chamber, it is a gas containing oxygen used in secondary combustion. In the secondary combustion gas supply structure provided for supplying the secondary combustion gas, which is one of three types of secondary air, circulating exhaust gas, and a mixed gas thereof.
The secondary combustion gas supply structure has a cross section cut by a plane perpendicular to the flow direction of the secondary combustion gas.
An inner pipe for forming an inner space through which the secondary combustion gas flows,
An outer tube that is located outside the inner space and surrounds the inner space to form an outer space through which a type of secondary combustion gas different from the secondary combustion gas flowing in the inner space flows. When,
With
The secondary combustion gas supply structure is characterized by having a configuration in which the combination of types of secondary combustion gas flowing in the inner space and the outer space is changed. A waste incinerator that performs primary combustion and secondary combustion that burns primary combustion gas including unburned gas generated in primary combustion in a combustion chamber.
It is equipped with a plurality of secondary combustion gas supply structures that supply a secondary combustion gas, which is a gas containing oxygen used in secondary combustion.
A waste incinerator, wherein at least one of the secondary combustion gas supply structures is the secondary combustion gas supply structure according to claim 2. The waste incinerator according to claim 3.
The waste incinerator is
A combustion sensor that detects data related to combustion in the combustion chamber,
An adjusting unit having a mechanism capable of adjusting the type of the secondary combustion gas supplied by the plurality of the secondary combustion gas supply structures, and
Control to adjust the types of secondary combustion gas supplied from the inner space and the outer space of the plurality of secondary combustion gas supply structures based on the combustion data detected by the combustion sensor. With the device
A waste incinerator characterized by being equipped with.

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