JP4135260B2 - Combustion air supply method and apparatus for stoker type incinerator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, when waste such as municipal waste is burned in a stoker-type incinerator, the temperature and oxygen concentration in the combustion chamber are stably maintained, and pollutants such as carbon monoxide (CO) and nitrogen oxides are retained. The present invention relates to a method and apparatus for supplying air for combustion in a stoker-type incinerator capable of suppressing generation.
[0002]
[Prior art]
As one of the incinerators for incinerating waste, there is a stoker-type incinerator that burns waste while being supported by a grate provided in a combustion chamber. A stair stoker type incinerator 1 as shown in FIGS. 3A and 3B and a rotary stoker type incinerator 2 as shown in FIGS. 4A, 4B and 4C are known.
[0003]
The stair stoker type incinerator 1 has a grate 5 provided with a large number of air holes 4 at the bottom in the primary combustion chamber 3 from the inlet side, as shown schematically in FIG. The stair stalker body 6 is formed in a staircase shape so that the exit side is lower, and each grate 5 of the stair stalker body 6 is caused to perform a required vibration by a driving device (not shown). In addition, the material placed on the upper side can be sent in order from the inlet side to the outlet side, and the waste 8 in the charging hopper 7 is supplied onto the staircase stoker main body 6 by the dust feeder 9 and downstream. Is sent to the waste 8 on the stair stalker body 6 through the air hole 4 from the wind box 10 arranged at the lower position of the stair stalker body 6 and connected to the primary combustion chamber 3. By blowing 11 to blow from below, An unburned gas generated by this combustion is led to a secondary combustion chamber 12 connected to the upper portion of the primary combustion chamber 3 and connected to the secondary combustion chamber 12. 13 is configured to be completely burned by the combustion air 11 supplied from 13.
[0004]
The air box 10 of the staircase stoker type incinerator 1 is provided with a plurality of, for example, three divided longitudinally divided flow passages 14 in the longitudinal direction (waste feed direction). Corresponding to the tendency that the layer thickness of the waste 8 is reduced by combustion from the inlet side to the outlet side, the combustion air is supplied to each of the longitudinally divided flow paths 14 on the inlet side, the intermediate part, and the outlet side. 11 is set to change the supply amount.
[0005]
On the other hand, the rotary stoker-type incinerator 2 is formed between the inlet-side header pipe 15 and the outlet-side header pipe 16 formed in a ring shape, as schematically shown in FIGS. 4 (a), (b), and (c). In addition, a large number of water pipes 17 are arranged at regular intervals in the circumferential direction so as to communicate with each other, and fins 19 having a large number of air holes 18 drilled at intervals in the longitudinal direction are attached to the gaps between the water pipes 17. A rotary stoker main body 21 as a cylindrical grate having an inside serving as a primary combustion chamber 20 is disposed, and the rotary stoker main body 21 is placed in a cover casing 22 with the outlet side header pipe 16 being more than the inlet side header pipe 15. The boiler water is laid down so as to be lowered and can be rotated and driven by the drive device 23, and the boiler water is circulated and circulated in each water pipe 17 through the rotary joint 24 connected to the outlet side header pipe 16. In the state where the rotary stalker main body 21 is driven to rotate at a low speed, the waste 8 in the charging hopper 7 is loaded into the rotary stalker main body 21 by the dust feeder 9, and the lower position of the rotary stalker main body 21 is set. The waste 8 is burned by supplying the combustion air 11 from below to the waste 8 in the rotary stoker main body 21 through the air hole 18 from the wind box 10 </ b> A arranged in the cover casing 22. The unburned gas generated by this combustion is sent to the secondary combustion chamber 26 together with the combustion air 11 supplied from the overcombustor air OCA supplier 25 provided at the upper position on the outlet side of the rotary stoker body 21, Complete combustion is performed by the combustion air 11 supplied from the air nozzle 13 connected to the secondary combustion chamber 26.
[0006]
Further, the wind box 10A of the rotary stoker-type incinerator 2 has a plurality of longitudinally divided flow paths in the longitudinal direction in the same manner as the wind box 10 of the stair stoker-type incinerator 1 shown in FIGS. 14 is set to change the supply amount of the combustion air 11 in accordance with the tendency that the thickness of the layer of the waste 8 is reduced by combustion from the inlet side to the outlet side in the rotary stoker body 21. Has been.
[0007]
In FIGS. 3 (a) and (b) and FIGS. 4 (a), (b), and (c), 8a represents waste that has burned to some extent among the waste 8, 27 represents flame, and FIG. 28 in 4 (a) (b) (c) is a post-combustion device for combustion ash.
[0008]
[Problems to be solved by the invention]
However, in the staircase stoker type incinerator 1 and the rotary stoker type incinerator 2, due to the difference in the progress speed of combustion due to the non-uniformity of the properties of the waste 8 charged, FIG. As shown by a two-dot chain line in FIG. 4B, a thin portion 8b is locally thin with respect to the layer of waste 8 located in the width direction on the stair stalker body 6 or in the rotary stalker body 21. In this case, the combustion air 11 that is uniformly supplied in the width direction from the longitudinal-direction divided flow paths 14 of the wind boxes 10 and 10A blows through the thin portion 8b of the waste 8 layer, and is primary. There is a problem that surplus air is generated in the combustion chambers 3 and 20, and the temperature in the primary combustion chambers 3 and 20 is lowered by the surplus air and carbon monoxide (CO) is increased due to incomplete combustion. In addition, the excess air Localized excess air combustion zone in the combustion chamber 3, 20, i.e., there is a problem that a possibility that the generation amount of nitrogen oxides a high oxygen concentration region is occurred (NOx) is increased occurs.
[0009]
Therefore, the present invention generates surplus air due to blow-off of combustion air even if a thin portion locally occurs in the waste layer burned on the grate due to the properties of the waste to be charged. To prevent the generation of pollutants such as carbon monoxide and nitrogen oxides, while maintaining a stable temperature and oxygen concentration in the combustion chamber It is.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the present invention supports waste by a grate provided in a combustion chamber, and supplies combustion air into the combustion chamber through a grate from a wind box provided below the grate. In the combustion air supply method for a stoker-type incinerator that is configured to burn waste , each division in the width direction of the divided flow path formed in the wind box is divided into a plurality of portions in the longitudinal direction and the width direction. A number of divided flow paths are provided so that the number of flow path divisions is greater on the downstream side in the longitudinal direction than on the upstream side , and each of the above divisions is determined from the supply pressure and flow rate of the combustion air supplied through each divided flow path. Combustion air by estimating the thickness of the waste located above the flow path and adjusting the supply amount for each of the divided flow paths so as to be an appropriate amount for burning the estimated thickness of waste. For the combustion of stoker-type incinerators Method and a grate provided with a large number of air holes at the bottom of the combustion chamber, and the waste supplied on the grate is combusted by combustion air blown from the lower wind box through the air holes In the stoker type incinerator, the number of divisions in the width direction of the division channel formed by dividing the wind box into a plurality of divisions in the longitudinal direction and the width direction is set to the downstream side in the longitudinal direction. A large number of divided flow paths are provided so as to be larger than the upstream side , and an air supply pipe for supplying combustion air is connected to each of the divided flow paths, and the flow rate is adjusted to each of the air supply pipes. A valve and a sensor for measuring the supply pressure and flow rate of the combustion air supplied to each of the divided flow paths; and further, the detected values of the supply pressure and flow rate detected by the sensors are input, Thickness of waste layer above each of the divided channels And a control device for adjusting the flow rate control valves so that an amount of combustion air suitable for combustion of the waste of the estimated thickness is supplied through the divided flow paths. A combustion air supply device for a stoker-type incinerator characterized by having a configuration provided, and water pipes arranged at regular intervals in the circumferential direction are connected by fins having a plurality of air holes, and the interior is Combustion in which a cylindrical grate as a combustion chamber is horizontally placed in a cover casing so as to be rotationally driven, and waste supplied into the cylindrical grate is blown from the lower air box through the air holes. In the rotary stoker incinerator designed to be burned with industrial air, the wind box is provided with a plurality of divided flow passages divided in the longitudinal direction and the width direction, and combustion air is supplied to the divided flow passages. in order to Each of the air supply pipes is connected, and each air supply pipe is provided with a flow rate adjusting valve and a sensor for measuring the supply pressure and flow rate of the combustion air supplied to each of the divided flow paths, Input the detected values of supply pressure and flow rate detected by each sensor to estimate the thickness of the waste layer above each of the divided flow paths, and suitable for burning waste of the estimated thickness A combustion air supply device for a stoker-type incinerator having a configuration in which each of the flow rate adjusting valves is adjusted so that a large amount of combustion air is supplied through each of the divided flow paths.
[0011]
If a thin portion is locally generated in the layer of waste burned on the grate due to the non-uniformity of the property of the supplied waste, it is supplied from the divided flow path of the wind box corresponding to the portion. A change occurs in which the flow rate increases as the supply pressure of the combustion air decreases. This change in supply pressure and flow rate is detected by a sensor corresponding to the divided flow path, and the thickness of the waste layer in the portion is estimated by the control device based on the detected value, and is suitable for the estimated thickness. The flow rate adjusting valve of the air supply pipe is throttled so that the supplied amount of combustion air is obtained.
[0012]
Further, in the stoker-type incinerator, the number of divisions in each of the divisional channels in the width direction is made larger on the downstream side in the longitudinal direction than on the upstream side, so that the combustion air is a waste layer. It is possible to appropriately adjust the supply amount of the combustion air on the downstream side where it is easy to blow through the thin part.
[0013]
Furthermore, in a stoker-type incinerator of a type in which a cylindrical grate is horizontally disposed so as to be able to rotate, the number of divisions of each division channel in the width direction is made larger on the upstream side in the longitudinal direction than on the downstream side. By doing so, it is possible to appropriately adjust the amount of supply of combustion air on the upstream side where the non-uniformity of the property of the waste is larger, and thereby the layer thickness of the waste tends to be more uneven. it can.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
FIGS. 1 (a), (b), and (c) show an embodiment of a combustion air supply method and apparatus for a stoker type incinerator according to the present invention, and are shown in FIGS. 3 (a) and (b). In the staircase stoker type incinerator 1 having the same configuration, the wind box 10 is divided into a plurality of parts in the width direction in addition to a plurality of parts in the longitudinal direction as in FIG. In this case, for example, each of the thin parts of the waste 8 is divided into three parts in the longitudinal direction so that the downstream side where the combustion air 11 is easy to blow through has a larger number of divisions in the width direction than the upstream side. When the flow path is formed, each of the divided flow paths 14 on the upstream side and the intermediate section is divided into two in the width direction, and the divided flow path 14 on the outlet side on the downstream side is divided into three in the width direction. Combustion air supplied from an air supply device (not shown) by forming a large number of divided flow passages 29 and connecting the air supply pipes 31 provided with flow rate adjusting valves 30 to the respective divided flow passages 29 in the width direction. 11 can be supplied to each divided flow path 29 via the flow rate adjusting valve 30, and each divided flow from each air supply pipe 31 to the downstream side position of the flow rate adjusting valve 30 of each air supply pipe 31. Blowing to waste 8 layers on stair stalker body 6 through road 29 A sensor 32 for measuring the supply pressure and flow rate of the combustion air 11 to be introduced is provided, and each flow rate of each air supply pipe 31 is determined based on the supply pressure detection value and the flow rate detection value obtained from each sensor 32. A control device 33 for adjusting the opening degree of the regulating valve 30 is provided. In addition, the same components as those shown in FIGS. 3A and 3B are denoted by the same reference numerals.
[0016]
The control device 33 receives the detection signals of the supply pressure and the supply flow rate of the combustion air 11 blown into the waste 8 through the air supply pipes 31 from the sensor 32, and based on the supply pressure detection signal and the flow rate detection signal. The thickness of the eight layers of waste for each divided section on the top surface of the staircase stoker body 6 corresponding to each divided flow path 29 to which the air supply pipe 31 to which each sensor 32 is attached is connected is estimated. Further, the opening degree of the corresponding flow rate adjusting valve 30 is adjusted so that an appropriate amount of combustion air 11 is supplied for combustion according to the thickness of the eight waste layers.
[0017]
That is, for example, when the waste 8 is burned due to the non-uniformity of the property of the waste 8 supplied onto the staircase stalker body 6, as shown by a two-dot chain line in FIG. When the thin portion 8b of the waste 8 layer is locally generated in the central portion on the outlet side in the longitudinal direction as compared with the both side portions in the width direction, the combustion air from the divided flow path 29 corresponding to the portion 8b 11 easily passes through the eight waste layers, and a decrease in the supply pressure and an increase in the flow rate of the combustion air 11 are detected by a sensor 32 provided in the air supply pipe 31 connected to the divided flow path 29. When this detection signal 34 is sent to the control device 33, the control device 33 determines the thickness of the waste 8 layer of the portion 8 b based on the detected decrease in the supply pressure of the combustion air 11 and the increase in the flow rate. So that the combustion air 11 is supplied in an appropriate amount that does not cause a blow-out even in the estimated eight layers of waste, that is, a smaller supply amount of combustion air 11. An operation command 35 is given to reduce the opening degree to the flow rate adjustment valve 30 of the air supply pipe 31, and the flow rate adjustment valve 30 is operated to reduce the thickness of the eight waste layers through the corresponding divided flow path 29 from the air supply pipe 31. The supply amount of the combustion air 11 supplied to the portion 8b is reduced.
[0018]
In this way, even if a thin portion 8b is locally generated in the waste 8 layer placed on the stair stoker body 6, it is possible to quickly prevent the combustion air 11 from being blown through the portion 8b. Therefore, it is possible to prevent excessive air from being generated in the internal combustion chamber 3. Therefore, the temperature in the primary combustion chamber 3 can be prevented from being lowered and the temperature in the primary combustion chamber 3 can be prevented from being excessively increased. And the oxygen concentration can be stably maintained, and the generation of contaminants such as carbon monoxide and nitrogen oxides can be suppressed. In addition, since the combustion air 11 having an appropriate supply amount is supplied in accordance with the thickness of the waste 8 layer, that is, the amount of the waste 8, the incineration and thermal decomposition of the waste 8 are promoted. Furthermore, since the supply of surplus air into the primary combustion chamber 3 can be prevented, the amount of exhaust gas can be reduced as compared with the prior art.
[0019]
Next, FIGS. 2 (a), (b) and (c) show another embodiment of the present invention, and a rotation having the same configuration as that shown in FIGS. 4 (a), (b) and (c). In addition to the formation of a plurality of divided flow paths 14 in the longitudinal direction similar to the embodiment shown in FIGS. A number of divided flow paths 29 are provided by dividing. In this case, the upstream side where the non-uniformity of the property of the waste 8 becomes larger has a larger number of divisions in the width direction than the downstream side, for example, each of the upstream side inlet side and the intermediate part In the divided flow path 14, a large number of divided flow paths 29 are formed in a configuration in which the divided flow path is divided into three in the width direction and the divided flow path 14 on the outlet side which is the downstream side is divided in the width direction. Further, an air supply device (not shown) is connected to each divided flow path 29 via an air supply pipe 31 provided with a flow rate adjusting valve 30 and a sensor 32, and each divided flow path 29 detected by the sensor 32 is connected. On the basis of the supply pressure and flow rate of the combustion air 11, the control device 33 is operated to adjust the opening degree of each flow rate adjusting valve 30. In addition, the same components as those shown in FIGS. 4A, 4B and 4C are denoted by the same reference numerals.
[0020]
According to the present embodiment, as shown by a two-dot chain line in FIG. 2B, when a thin portion 8b is generated in the waste 8 layer, it corresponds to the portion 8b as in the above embodiment. The supply amount of the combustion air 11 from the divided flow path 29 can be reduced to prevent the generation of excess air in the primary combustion chamber 20, and the generation of pollutants such as carbon monoxide and nitrogen oxides Can be suppressed.
[0021]
In addition, this invention is not limited only to the said embodiment, Each division | segmentation number of the division | segmentation flow path 29 of the width direction for every division | segmentation flow path 14 of a longitudinal direction is the staircase stoker type incinerator 1 or rotary stoker type. Of course, it may be determined freely according to the size of the incinerator 2, and other various modifications can be made without departing from the scope of the present invention.
[0022]
【The invention's effect】
As described above, according to the combustion air supply method and apparatus for the stoker type incinerator of the present invention, the waste box is supported by the grate provided in the combustion chamber, and the wind box provided at the lower position of the grate. A combustion air supply method for a stoker-type incinerator in which combustion air is supplied through a grate into the combustion chamber to burn waste, and the wind box is divided into a plurality of parts in the longitudinal direction and the width direction. A large number of divided flow paths are provided so that the number of divided flow paths in the width direction of the divided flow paths formed is greater on the downstream side in the longitudinal direction than on the upstream side , and supplied through each divided flow path. The thickness of the waste located above each of the divided flow paths is estimated from the supply pressure and flow rate of the combustion air, and each of the divided flows is adjusted to an amount appropriate for burning the estimated thickness of waste. Method of supplying combustion air by adjusting the supply amount for each road A grate having a large number of air holes is arranged at the bottom of the combustion chamber so that the waste supplied on the grate is burned by the combustion air blown from the lower wind box through the air holes. In the above-mentioned wind box in a stoker type incinerator, the number of divisions of each division channel in the width direction of the division channel formed by dividing into plural in the longitudinal direction and in the width direction is set upstream in the downstream side in the longitudinal direction. A plurality of divided flow paths are provided so as to be larger than the side , and an air supply pipe for supplying combustion air to each of the divided flow paths is connected to each of the air supply pipes. And a sensor for measuring the supply pressure and flow rate of the combustion air supplied to each of the divided flow paths, and further input the detected values of the supply pressure and flow rate detected by the sensors, Estimate the thickness of the waste layer above the division channel And a control device for adjusting the flow rate adjusting valves so that an amount of combustion air suitable for burning the estimated thickness of waste is supplied through the divided flow paths. The device has a structure, and water pipes arranged at regular intervals in the circumferential direction are connected by fins with a large number of air holes, and a cylindrical grate having an internal combustion chamber is rotated into the cover casing. The above-mentioned in a rotary stoker type incinerator which is horizontally placed so as to be drivable and is burned by combustion air blown from the lower wind box through the air hole. The air box is provided with a plurality of divided flow paths each divided in the longitudinal direction and the width direction, and air supply pipes for supplying combustion air are connected to the divided flow paths, respectively. Flow control valve on the pipe And a sensor for measuring the supply pressure and flow rate of the combustion air supplied to each of the divided flow paths, and further input the detected values of the supply pressure and flow rate detected by the sensors, The thickness of the waste layer located above each divided flow path is estimated, and an amount of combustion air suitable for combustion of the estimated thickness of waste is supplied through each divided flow path. Since it is a device having a configuration provided with a control device for adjusting each flow regulating valve, even if a locally thin portion occurs in the layer of waste burned on the grate, it corresponds to that portion It is possible to prevent the surplus air from being generated in the combustion chamber by quickly setting the amount of combustion air supplied from the divided flow path of the wind box to an appropriate amount. This can prevent a decrease in temperature and an increase in oxygen concentration. Can maintain the combustion chamber at a high temperature and stably maintain the oxygen concentration, thereby suppressing the generation of pollutants such as carbon monoxide and nitrogen oxides (NOx). It is possible to promote the thermal decomposition of the waste because it can be an appropriate air supply amount according to the layer thickness of the waste above, and further, eliminate excess air and reduce the amount of exhaust gas Demonstrate the excellent effect of being able to. Furthermore, as described above, in the stoker-type incinerator, the number of divisions in each widthwise divided flow path is configured such that the downstream side in the longitudinal direction is larger than the upstream side , and the cylindrical shape in format stoker incinerator that horizontally the grate to be rotated, since the direction of the longitudinal direction of the upstream side are to be more than the downstream side, the adjustment of the supply quantity of combustion air more Demonstrate the effect that it can be done properly.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows an embodiment of a combustion air supply method and apparatus for a stoker-type incinerator according to the present invention, in which (A) is a schematic cut-away side view and (B) is an AA arrow of (A). (C) is a view taken along the line B-B of (A).
FIGS. 2A and 2B show another embodiment of the present invention, where FIG. 2A is a schematic side view of a cut, FIG. 2B is a view taken along the line CC of FIG. 2A, and FIG. FIG.
FIG. 3 shows an outline of an example of a conventional staircase-type incinerator, in which (a) is a schematic cut-away side view, and (b) is a view taken along the line EE of (a).
FIG. 4 shows an outline of an example of a conventional rotary stoker incinerator, in which (A) is a schematic side view of cutting, (B) is a view taken along the line FF of (A), and (C) is (I). FIG.
[Explanation of symbols]
1 staircase stoker-type incinerator (stoker-type incinerator)
2 Rotating stoker type incinerator (stoker type incinerator)
3 Primary combustion chamber (combustion chamber)
4 Air hole 5 Grate 6 Stair stalker body 8, 8a Waste 8b Part 10, 10A Wind box 11 Combustion air 17 Water pipe 18 Air hole 19 Fin 20 Primary combustion chamber (combustion chamber)
21 Rotating stoker body (grate)
22 Cover casing 29 Divided flow path 30 Flow rate adjusting valve 31 Air supply pipe 32 Sensor 33 Control device

Claims (4)

A stoker configured to support waste by a grate provided in the combustion chamber and to burn the waste by supplying combustion air from the wind box provided below the grate through the grate into the combustion chamber. In the combustion air supply method of the incinerator, the number of divisions in the width direction of the divided flow paths formed in the wind box is divided into a plurality of divisions in the longitudinal direction and the width direction . the thickness towards the upstream side more so as to the number of divided flow paths provided than waste position from the supply pressure and the flow rate of combustion air supplied to the upper portion of each of the divided flow paths through each divided flow paths A stoker-type incinerator characterized in that the combustion air is supplied by adjusting the supply amount for each of the divided flow paths so that the amount is appropriate for the combustion of the waste of the estimated thickness Air supply method for combustion. A grate having a large number of air holes is arranged at the bottom of the combustion chamber, and the waste supplied on the grate is burned by the combustion air blown from the lower wind box through the air holes. In the above-mentioned stoker type incinerator, the division number of each divided flow path in the width direction of the divided flow path formed in the longitudinal direction and the width direction in the wind box is set upstream on the downstream side in the longitudinal direction. A plurality of divided flow paths so as to be larger than the above, and an air supply pipe for supplying combustion air to each of the divided flow paths is connected to each of the air supply pipes. A sensor for measuring the supply pressure and the flow rate of the combustion air supplied to each of the divided flow paths is provided, and further, the detected values of the supply pressure and the flow rate detected by the sensors are input, Estimate the thickness of the waste layer above the flow path And a control device that adjusts each of the flow rate control valves so that an amount of combustion air suitable for combustion of waste having an estimated thickness is supplied through each of the divided flow paths. An air supply device for combustion of a stoker type incinerator.   Water pipes arranged at regular intervals in the circumferential direction are connected by fins having a large number of air holes, and a cylindrical grate having a combustion chamber inside is horizontally placed in a cover casing so as to be rotationally driven. The waste box supplied in the cylindrical grate is burned by the combustion air blown from the lower wind box through the air hole, and the wind box in the rotary stoker type incinerator has a longitudinal direction and a width. A plurality of divided flow paths each divided in a direction are provided, and an air supply pipe for supplying combustion air to each of the divided flow paths is connected to each of the air supply pipes. A sensor for measuring the supply pressure and flow rate of the combustion air supplied to each of the divided flow paths is provided, and the detected values of the supply pressure and flow rate detected by the sensors are further input, Becomes the upper position of the flow path Estimating the thickness of the waste layer, and adjusting each of the flow control valves so that an amount of combustion air suitable for burning the estimated thickness of waste is supplied through each of the divided flow paths. A combustion air supply device for a stoker-type incinerator having a configuration in which a control device is provided.   The combustion air supply device for a stoker-type incinerator according to claim 3, wherein the number of divisions of each divided flow path in the width direction is made larger on the upstream side in the longitudinal direction than on the downstream side.

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