JP5981801B2 - Incinerator denitration method and incinerator denitration system - Google Patents

Description

  The present invention relates to a denitration method for an incinerator and a denitration system for an incinerator in which a denitration agent such as ammonia water or urea water is blown into a combustion chamber of an incinerator that incinerates by burning waste.

  An example of a conventional denitration method for an incinerator will be described with reference to FIGS. 4 and 5 (see, for example, Patent Document 1). In this incinerator denitration method, as shown in FIG. 4, first, in a first stage, the waste 5 on the grate 1 in the combustion chamber 2 is burned by supplying the primary air 6. Next, in the second stage, oxygen-free or low-oxygen combustion exhaust gas (mixed medium) 8 is mixed with the combustion exhaust gas 7 generated in the first stage. Then, the air-fuel mixture 9 generated thereby is retained in the retention zone 3 for at least 0.3 seconds. Next, the denitration agent (reducing agent) 11 is substantially mixed with the secondary air 10 and blown into the air-fuel mixture 9. As a result, the nitrogen oxide concentration in the air-fuel mixture 9 is reduced, and the air-fuel mixture 9 mixed with the secondary air 10 is completely combusted in the post-combustor 4 to become combustion exhaust gas 12 and sent downstream. .

  According to the denitration method of the incinerator, since the denitration agent (reducing agent) 11 is substantially mixed with the secondary air 10 and blown into the air-fuel mixture 9, no additional equipment for blowing the denitration agent 11 is required. At the same time, since the denitration drug 11 is supplied together with the secondary air 10 having a larger flow rate, mixing with the air-fuel mixture 9 is effectively performed.

JP 2001-90920 A

However, the conventional incinerator denitration method has the following problems. FIG. 5 is a diagram schematically showing the relationship between the gas flow position L of the combustion exhaust gas in the combustion chamber 2 shown in FIG. 4, the nitrogen oxide (NO _X ) concentration N of the combustion exhaust gas, and the gas temperature T.

  As shown in FIG. 5, in the combustion exhaust gas 7 generated by supplying the primary air 6 at the gas flow position L1 in the combustion chamber 2, the gas temperature T is T1 and the nitrogen oxide concentration N is N1. Next, when the combustion exhaust gas 8 is supplied to the combustion exhaust gas 7 at the gas flow position L2, the gas temperature T decreases to T2, and the nitrogen oxide concentration N decreases to N2. When the denitration agent (reducing agent) 11 is substantially mixed with the secondary air 10 and supplied to the combustion exhaust gas 9 at the gas flow position L3, the gas temperature T decreases to T3 due to the supply of the denitration agent 11. When the secondary air 10 is supplied, the combustion exhaust gas 9 is completely burned, so that the temperature rises from T3 to T4. As described above, in FIG. 5, the change in the gas temperature T is shown by distinguishing between the effect of supplying the denitration drug 11 and the effect of supplying the secondary air 10. At the flow position L3, the gas temperature T is substantially T4.

  Further, the nitrogen oxide concentration N decreases to N3 due to the denitration reaction by the denitration agent 11, and increases to N4 by the combustion reaction due to the supply of the secondary air 10. Thus, in FIG. 5, as with the gas temperature T, the nitrogen oxide concentration N also shows the effect of supplying the denitration chemical 11 and the effect of supplying the secondary air 10 separately. Because of the simultaneous reaction, the nitrogen oxide concentration N is substantially N4 at the gas flow position L3.

  As described above, the conventional incinerator denitration method shown in FIG. 4 cannot sufficiently utilize the effect of reducing the nitrogen oxide concentration N by the denitration chemical 11, and the combustion exhaust gas in which the nitrogen oxide concentration N is increased. There is a problem that 12 (nitrogen oxide concentration N4) is released into the atmosphere.

  The present invention has been made to solve the above-described problems, and reduces the nitrogen oxide concentration in the combustion exhaust gas by reducing the nitrogen oxide concentration in the combustion exhaust gas discharged from the combustion chamber. An object of the present invention is to provide a denitration method for an incinerator and a denitration system for an incinerator that can omit or reduce the size of a catalytic reaction facility.

  The denitration method for an incinerator according to the present invention is such that primary air and secondary air are blown into a combustion chamber, and the waste is burned to incinerate the combustion chamber of the incinerator after combustion in the combustion chamber. In the denitration method of an incinerator for denitrating by blowing in combustion exhaust gas and denitration chemical, the position where the denitration chemical is blown into the combustion chamber is more gas than the position where primary air, secondary air, and combustion exhaust gas are blown into the combustion chamber. It is the downstream of the flow direction.

According to the incinerator to which the denitration method for an incinerator according to the present invention is applied, primary air and secondary air are blown into the combustion chamber, and the waste can be combusted for incineration. And, according to the denitration method for an incinerator according to the present invention, by blowing a combustion exhaust gas having a lower oxygen (O ₂ ) concentration than air into the combustion chamber, local combustion is suppressed and nitrogen oxides (NO _X ) Generation | occurrence | production can be suppressed (it can denitrate substantially), As a result, reduction of the nitrogen oxide density | concentration in the combustion exhaust gas in a combustion chamber can be aimed at.

Further, the position where the denitration chemical is blown into the combustion chamber is located downstream of the position where the primary air, secondary air, and combustion exhaust gas are blown into the combustion chamber in the gas flow direction. NO _x ) concentration-reduced (denitrated) combustion exhaust gas can be released into the atmosphere.

  Then, the nitrogen oxide concentration in the combustion exhaust gas in the combustion chamber is reduced by blowing the combustion exhaust gas into the combustion chamber, and then the NOx removal chemical is blown into the combustion exhaust gas in which the nitrogen oxide concentration is reduced. Therefore, the amount of denitration chemical necessary to reduce the nitrogen oxide concentration in the combustion exhaust gas to a predetermined value can be reduced.

  In the denitration method for an incinerator according to the present invention, a plurality of temperature detectors for detecting the temperature in the combustion chamber and a plurality of denitration agent blowing parts for blowing denitration agent are provided in the combustion chamber. And based on the measured temperatures detected by the plurality of temperature detectors, provided at a spatial position of the measured temperature having a high denitration efficiency obtained from the relationship between the temperature and the denitration efficiency, corresponding to the spatial position. The denitration drug is preferably blown from the denitration drug blowing section.

  In this way, based on the measured temperatures detected by the plurality of temperature detectors provided in the combustion chamber, the spatial position of the measured temperature having a high denitration efficiency obtained from the relationship between the temperature and the denitration efficiency is obtained. The denitration drug can be blown from the denitration drug blowing section provided corresponding to the above. Here, the relationship between the temperature and the denitration efficiency is a relationship in which the denitration efficiency when the denitration agent is blown into the combustion exhaust gas containing nitrogen oxide has a predetermined difference depending on the temperature of the combustion exhaust gas. Therefore, the nitrogen oxide concentration in the combustion exhaust gas can be effectively reduced (denitration) by blowing the denitration chemical into the space where the combustion exhaust gas at a temperature at which high denitration efficiency is obtained.

  In the denitration method for an incinerator according to the present invention, the spatial position of the measurement temperature with high denitration efficiency may be a spatial position within a range of the measurement temperature of 800 to 1000 ° C.

  Thus, since the spatial position of the measurement temperature with high denitration efficiency is a spatial position within the range of the measurement temperature of 800 to 1000 ° C., nitrogen oxides in combustion exhaust gas are injected by blowing the denitration chemical into this spatial position. The concentration can be effectively reduced.

  In the denitration method for an incinerator according to the present invention, the combustion exhaust gas blown into the combustion chamber is a part of the treated combustion exhaust gas processed by the exhaust gas treatment facility, and the remaining combustion exhaust gas is denitrated by the catalytic reaction facility. You should do it.

  As described above, when the treated exhaust gas treated by the exhaust gas treatment facility such as the bag filter is used as the combustion exhaust gas blown into the combustion chamber, the combustion exhaust gas is caused by soot or the like in the combustion exhaust gas blown into the combustion chamber. It is possible to prevent the circulating line and the like passing through from becoming dirty. Since the combustion exhaust gas discharged from the exhaust gas treatment facility is denitrated by the circulating combustion exhaust gas and the denitration chemical, when providing a catalytic reaction facility for further denitration of this combustion exhaust gas, Miniaturization can be achieved.

  In the denitration method for an incinerator according to the present invention, the leaked ammonia resulting from the denitration chemical blown into the combustion chamber may be used for the catalytic reaction in the catalytic reaction facility.

  Thereby, simplification of the ammonia supply part provided in the catalytic reaction facility can be achieved.

  The denitration system for an incinerator according to the present invention blows primary air and secondary air into a combustion chamber, burns waste, and incinerates the combustion chamber of the incinerator after combustion in the combustion chamber. In a denitration system of an incinerator for denitrating by blowing exhaust gas and denitration chemical, a position where the denitration chemical is blown into the combustion chamber is a gas flow direction than a position where primary air, secondary air and combustion exhaust gas are blown into the combustion chamber It is characterized by being on the downstream side.

  The incinerator denitration system according to the present invention uses the incinerator denitration method according to the present invention, and operates in the same manner as the incinerator denitration method according to the present invention.

According to the incinerator denitration method and the incinerator denitration system according to the present invention, the position in which the denitration chemical is blown into the combustion chamber is greater than the position in which the primary air, secondary air, and combustion exhaust gas are blown into the combustion chamber. by the downstream side of the nitrogen oxide (NO _X) combustion exhaust gas concentration is greatly reduced can be released into the atmosphere. As a result, the catalytic reaction equipment for reducing the concentration of nitrogen oxides in the combustion exhaust gas can be omitted or downsized, so that the cost can be reduced accordingly. As a result, it is possible to simplify the incinerator denitration system in which this incinerator denitration method is used.

  By omitting or downsizing the catalytic reaction facility, it is not necessary to reheat the combustion exhaust gas with steam necessary for the catalytic reaction facility, or the amount of heat necessary for reheating can be reduced. . As a result, when power is generated by the power generator using the heat generated from the incinerator, the power generation efficiency of the power generator can be improved.

1 is a system diagram showing an incinerator in which an incinerator denitration method according to an embodiment of the present invention is used. A gas flow position of the combustion exhaust gas of the combustion chamber shown in FIG. 1 is a schematic diagram showing the relationship between the combustion nitrogen oxides of exhaust gases (NO _X) concentration and gas temperature. It is a block diagram which shows the control circuit of the incinerator which concerns on the same embodiment. It is a systematic diagram which shows the incinerator in which the denitration method of the conventional incinerator is used. A gas flow position of the combustion exhaust gas of the combustion chamber shown in FIG. 4 is a schematic diagram showing the relationship between the combustion nitrogen oxides of exhaust gases (NO _X) concentration and gas temperature.

  Hereinafter, an embodiment of an incinerator in which the denitration method for an incinerator according to the present invention is used will be described with reference to FIGS. An incinerator denitration system 15 in which the denitration method is used is applied to the incinerator 14 shown in FIG. The denitration system 15 can be applied to, for example, an incinerator 14 that combusts the waste 5 in a combustion chamber 18 having a primary combustion chamber 16 and a secondary combustion chamber 17, and the primary combustion chamber 15. The combustion exhaust gas 19 after combustion in the combustion chamber 18 is blown into the combustion chamber 18 and the denitration chemical 20 is blown into the secondary combustion chamber 17 so that the combustion exhaust gas 21 in the combustion chamber 18 can be denitrated. is there. Note that primary air 22 and secondary air 23 are blown into the primary combustion chamber 16.

  The incinerator 14 shown in FIG. 1 includes a hopper (not shown) to which wastes 5 (incinerators) such as various kinds of garbage are supplied. The hopper is connected to the primary combustion chamber 16 through a chute, and the waste 5 supplied from the hopper is sent to the primary combustion chamber 16 through the chute. The primary combustion chamber 16 is provided with a stoker 24. From the lower side of the stalker 24, the primary air 22 is sent from the primary air supply port 25, and the secondary air 23 for burning unburned gas from the ceiling or side wall of the primary combustion chamber 16 is the secondary air supply port. Sent from the unit 26.

  As shown in FIG. 1, the secondary combustion chamber 17 is connected to the primary combustion chamber 16, and the combustion exhaust gas 21 generated by the combustion of the waste 5 is sent from the primary combustion chamber 16 to the secondary combustion chamber 17. It will come. The combustion exhaust gas 21 is combusted again in the secondary combustion chamber 17 and then recovered in the first radiation chamber of a waste heat boiler provided on the downstream side (not shown), and further passes through the second radiation chamber. Guided to an economizer. Then, after the detoxification process is performed in the exhaust gas treatment facility, it is discharged to the atmosphere through an induction fan and a chimney.

  Then, the combustion exhaust gas 19 partially extracted from the exhaust gas treatment facility passes through, for example, the first to third exhaust gas recirculation gas pipes 27 as shown in FIG. The gas is introduced into the gas supply port 28 and blown into the primary combustion chamber 16. The reason why the flue gas 19 is blown into the primary combustion chamber 16 is to reduce the nitrogen oxide concentration in the flue gas 21 in the primary combustion chamber 16.

The combustion exhaust gas 19 introduced into the first to third gas supply ports 28 of the primary combustion chamber 16 through the first to third exhaust gas recirculation gas pipes 27 has a temperature T of 150 to 200 ° C., for example. , O ₂ concentration O is 5 to 10%.

  Moreover, the 1st-3rd gas supply port part 28 shown in FIG. 1 is provided in the ceiling of the primary combustion chamber 16, a partition wall, a side wall, etc. Each of the first to third exhaust gas recirculation gas pipes 27 connected to the first to third gas supply ports 28 is provided with first to third gas valves 29 (regulating valves).

  By opening the desired gas valve 29 among the first to third gas valves 29, the combustion exhaust gas 19 is discharged from the desired gas supply port portion 28 provided on the ceiling, partition wall, and side wall of the primary combustion chamber 16. The air can be blown into the primary combustion chamber 16. And these 1st-3rd gas valves 29 are comprised so that opening / closing control may be performed by the control part 30 (central processing unit) shown in FIG. 3 according to the program memorize | stored in the memory | storage part (not shown). Yes.

  The exhaust gas recirculation facility 46 configured as described above enters the primary combustion chamber 16 of the combustion exhaust gas 19 based on the operating conditions of the incinerator 14 at the adjustment stage before the actual operation of the incinerator 14 shown in FIG. The circulation position (blowing position) and the circulation flow rate (blowing flow rate) are appropriately set.

  Here, that the circulation position (blowing position) and the circulation flow rate (blowing flow rate) into the primary combustion chamber 16 of the combustion exhaust gas 19 are set appropriately are the first to first denitration chemicals 20 described later. The nitrogen oxide concentration in the combustion exhaust gas 21 discharged from the chimney of the incinerator 14 shown in FIG. 1 is determined in advance in a state where the fuel is not blown into the secondary combustion chamber 17 from the three spray nozzles 31, 32, 33. This means that the exhaust gas recirculation facility 46 is set so as to be lower than the specified value.

  Here, as a method of determining the optimum circulation position (the gas supply port portion 28 through which the combustion exhaust gas 19 is blown out), the setting of the open / close state of each of the first to third gas valves 29 shown in FIG. 1 is variously changed. Then, by selecting the setting of the open / close state of the gas valve 29 that allows the nitrogen oxide concentration in the combustion exhaust gas 21 emitted from the chimney of the incinerator 14 to be relatively low, the optimum circulation is achieved. There is a way to determine the position.

  However, the nitrogen oxide concentration in the combustion exhaust gas 21 emitted from the chimney is detected by a nitrogen oxide concentration detector (not shown) provided at the chimney inlet. This nitrogen oxide concentration detector is electrically connected to the control unit 30.

  Then, as a method of determining the optimum circulation flow rate (flow rate of the combustion exhaust gas 19 blown out from the gas supply port portion 28), the opening degree of each of the first to third gas valves 29 shown in FIG. Thus, the optimum circulation flow rate is determined by selecting the opening degree of the gas valve 29 that allows the nitrogen oxide concentration in the combustion exhaust gas 21 discharged from the chimney of the incinerator 14 to be relatively low. There is a way to do it.

  As shown in FIG. 1, a plurality of first to third spray nozzles 31, 32, and 33 (denitration chemical blowing portions) are attached to the side wall of the secondary combustion chamber 17. These first to third spray nozzles 31, 32, 33 are for blowing the denitration chemical 20 such as ammonia water or urea water into the secondary combustion chamber 17. The medicine supply pipes 34, 35, and 36 are connected. The denitration drug 20 is introduced into the first to third denitration drug supply pipes 34, 35, and 36 together with carry water by a pump.

  These first to third spray nozzles 31, 32, 33 are arranged so as to be continuous in a direction substantially orthogonal to the gas flow direction 40 and are provided in three rows. In each row, three spray nozzles 31 and the like are provided. The three first spray nozzles 31 provided on the most downstream side in the gas flow direction 40 are provided in the first denitration chemical supply pipe 34. Then, the three second spray nozzles 32 arranged at positions upstream of the first spray nozzle 31 are provided in the second denitration chemical supply pipe 35 and further upstream of the second spray nozzle 32. The three third spray nozzles 33 arranged at the positions are provided in the third denitration drug supply pipe 36. The first to third denitration drug supply pipes 34 and the like are provided with first to third drug valves 37, 38, and 39 (regulating valves).

  By opening a desired drug valve 37 or the like among the first to third drug valves 37, 38, and 39, the denitration drug 20 is supplied from the desired spray nozzle 31 provided on the side wall of the secondary combustion chamber 17. It can be blown into the next combustion chamber 17. And these 1st-3rd chemical | medical agent valves 37,38,39 are comprised so that opening / closing control may be performed by the control part 30 shown in FIG. 3 according to the program memorize | stored in the memory | storage part (not shown).

  Further, as shown in FIG. 1, for example, four first to fourth temperature detectors 41 to 44 are attached to the side wall of the secondary combustion chamber 17. These first to fourth temperature detectors 41 to 44 are for detecting the temperature in the secondary combustion chamber 17, and are electrically connected to the control unit 30 shown in FIG. The first and second temperature detectors 41 and 42 are positioned downstream of the three first spray nozzles 31 in the gas flow direction 40 and are spaced from each other in a direction perpendicular to the gas flow direction 40. Are provided apart from each other. The third and fourth temperature detectors 43 and 44 are spaced from each other in a direction substantially orthogonal to the gas flow direction 40 at a position upstream of the three third spray nozzles 33 in the gas flow direction 40. It is provided apart.

Next, the operation of the incinerator denitration method configured as described above, the incinerator denitration system 15, and the operation of the incinerator 14 to which the denitration method is applied will be described. According to the incinerator 14 shown in FIG. 1, the primary air 22 and the secondary air 23 are blown into the primary combustion chamber 16 to burn the waste 5 for incineration. And, according to the denitration method for an incinerator according to the present invention, combustion exhaust gas having a lower oxygen (O ₂ ) concentration (for example, 5 to 10%) than air in the primary combustion chamber 16 (for example, the gas temperature is 1000 to 1100 ° C.). 19 by blowing (e.g., gas temperature 150 to 200 ° C.), nitrogen oxides by suppressing local combustion (NO _X) it is possible to suppress the occurrence of (substantially can denitrification), the result Further, it is possible to reduce the nitrogen oxide concentration in the flue gas 21 of the primary combustion chamber 16 (for example, the concentration is 60 to 80 ppm).

Further, as shown in FIG. 1, the denitration chemical 20 is blown at a position downstream of the primary air 22, secondary air 23, and combustion exhaust gas 19 in the gas flow direction 40. 20, the combustion exhaust gas 21 in which the concentration of nitrogen oxides (NO _x ) is reduced (for example, the concentration is 50 ppm or less lower than 60 to 80 ppm) (denitrated) can be released into the atmosphere.

  That is, the position where the denitration chemical 20 is blown is the position where the first to third spray nozzles 31, 32, 33 are provided, and the first to third spray nozzles 31, 32, 33 are the secondary combustion chambers. 17 is provided. The position where the primary air 22 is blown is the position where the primary air supply port 25 is provided, and the position where the secondary air 23 is blown is the position where the secondary air supply port 26 is provided. And the position which blows in the combustion exhaust gas 19 is a position in which the 1st-3rd gas supply port part 28 is provided. The primary air supply port 25, the secondary air supply port 26, and the first to third gas supply ports 28 are provided in the primary combustion chamber 16 upstream of the secondary combustion chamber 17.

  In the primary combustion chamber 16, the flue gas 19 is blown from the first to third gas supply ports 28, thereby reducing the nitrogen oxide concentration in the flue gas 21 of the primary combustion chamber 16. In the next combustion chamber 17, the NOx removal chemical 20 is blown from the first to third spray nozzles 31, 32, 33 into the combustion exhaust gas 21 whose nitrogen oxide concentration is reduced so as to further reduce the nitrogen oxide concentration. Therefore, it is possible to reduce the amount of denitration chemical necessary to reduce the nitrogen oxide concentration in the combustion exhaust gas 21 until it reaches a predetermined value.

In this way, the nitrogen oxide (NO _x ) concentration in the combustion exhaust gas 21 can be greatly reduced, and the combustion exhaust gas 21 can be released into the atmosphere. Thereby, since the catalytic reaction equipment for reducing the nitrogen oxide concentration in the combustion exhaust gas 21 can be omitted or downsized, the cost can be reduced accordingly. As a result, the incinerator denitration system 15 used in this incinerator denitration method can be simplified.

  By omitting or downsizing the catalytic reaction facility, it is not necessary to reheat the combustion exhaust gas 21 with the steam necessary for the catalytic reaction facility, or the amount of heat necessary for reheating can be reduced. it can. As a result, when power is generated by the power generation device using the heat generated from the incinerator 14, the power generation efficiency of the power generation device can be improved.

  In addition, when providing a catalytic reaction equipment in this incinerator 14, it is provided in the downstream of the exhaust gas treatment equipment containing a bag filter etc.

  Moreover, the control part 30 shown in FIG. 3 is the space of measurement temperature with high denitration efficiency calculated | required from the relationship between temperature and denitration efficiency based on the measured temperature detected by the 1st-4th temperature detectors 41-44. Any one of the first to third spray nozzles 31, 32, 33 (denitration chemical blowing part) provided corresponding to the space position, or all the spray nozzles 31. The denitration medicine 20 is blown from the like.

  If it does in this way, based on the measured temperature detected with the 1st-4th temperature detectors 41-44 provided in the secondary combustion chamber 17, the denitration efficiency calculated | required from the relationship between temperature and denitration efficiency is high. The denitration chemical 20 can be blown into the space position of the measurement temperature from the spray nozzle 31 provided corresponding to the space position.

  Here, the relationship between the temperature and the denitration efficiency is a relationship that the denitration efficiency when the denitration chemical 20 is blown into the combustion exhaust gas 21 containing nitrogen oxide has a predetermined difference depending on the temperature of the combustion exhaust gas 21. It is. Therefore, the nitrogen oxide concentration in the combustion exhaust gas 21 can be effectively reduced by blowing the denitration chemical 20 into the space where the combustion exhaust gas 21 at a temperature at which high denitration efficiency is obtained.

  In this embodiment, the spatial position of the measurement temperature with high denitration efficiency is a spatial position in which the measurement temperature is 800 to 1000 ° C., preferably 850 to 950 ° C.

  Thus, since the spatial position of the measurement temperature with high denitration efficiency is a spatial position in the range of the measurement temperature of 800 to 1000 ° C., preferably 850 to 950 ° C., the denitration chemical 20 is blown into this spatial position. Thus, the nitrogen oxide concentration in the combustion exhaust gas 21 can be effectively reduced.

  The denitration efficiency is an efficiency that can reduce the concentration of nitrogen oxides in the combustion exhaust gas 21. For example, the NOx removal agent 20 is blown into the combustion exhaust gas 21 having a nitrogen oxide concentration of 100 ppm. When the concentration can be reduced to 40 ppm, it can be said that the denitration efficiency is higher than when the concentration can be reduced to 60 ppm.

Next, FIG. 2 will be described. FIG. 2 shows the relationship between the gas flow position L of the combustion exhaust gas 21 in the primary and secondary combustion chambers 16 and 17 shown in FIG. 1, the nitrogen oxide (NO _x ) concentration N of the combustion exhaust gas 21, and the gas temperature T. It is a schematic diagram shown.

  As shown in FIG. 2, in the state where the secondary air 23 is supplied to the combustion exhaust gas 21 at the gas flow position L5 in the primary combustion chamber 16, the gas temperature T is T5 and the nitrogen oxide concentration N is N5. It is. Next, when the combustion exhaust gas 19 circulating to the combustion exhaust gas 21 is supplied at the gas flow position L6, the gas temperature T decreases to T6, and the nitrogen oxide concentration N decreases to N6. When the denitration chemical 20 is supplied to the combustion exhaust gas 21 at the gas flow position L7 in the primary combustion chamber 16, the gas temperature T is further lowered to T7, and the nitrogen oxide concentration N is further lowered to N7.

  As described above, according to the denitration method of the incinerator shown in FIG. 2, the effect of reducing the nitrogen oxide concentration N by the circulating combustion exhaust gas 19 and the denitration chemical 20 can be sufficiently exerted, and the nitrogen oxide concentration N can be reduced. The sufficiently reduced combustion exhaust gas 21 (nitrogen oxide concentration N7) can be released into the atmosphere.

  However, in the above embodiment, a part of the treated combustion exhaust gas 21 (combustion exhaust gas 19) processed by the exhaust gas treatment facility is circulated and blown into the primary combustion chamber 16, and the remaining combustion exhaust gas 21 is discharged from the chimney to the atmosphere. However, instead of this, the remaining combustion exhaust gas 21 may be denitrated by the catalytic reaction facility and then discharged from the chimney to the atmosphere.

  As the combustion exhaust gas 19 blown into the primary combustion chamber 16, the combustion exhaust gas 19 before being processed by the exhaust gas processing facility may be used. However, when the processed exhaust gas processed by the exhaust gas processing facility such as a bag filter is used, The first to third exhaust gas recirculation gas pipes 27 through which the combustion exhaust gas 19 passes can be prevented from being contaminated by soot or the like in the combustion exhaust gas 19 blown into the primary combustion chamber 16. And since the combustion exhaust gas 21 discharged from the exhaust gas treatment facility is denitrated by the circulating combustion exhaust gas 19 and the denitration chemical 20, when providing a catalytic reaction facility for further denitration of this combustion exhaust gas 21, The catalytic reaction equipment can be downsized.

  Then, the leaked ammonia resulting from the denitration chemical 20 blown into the secondary combustion chamber 17 may be used for the catalytic reaction in the catalytic reaction facility. If it does in this way, simplification of the ammonia supply part provided in a catalytic reaction equipment can be aimed at.

  Moreover, although the incinerator 14 of the said embodiment gave the grate type thing as an example, it replaced with this and may be a fluidized bed type thing.

  Furthermore, in the said embodiment, as shown in FIG. 1, the 1st-3rd spray nozzles 31, 32, 33, the 1st-3rd denitration chemical | medical agent supply pipes 34, 35, 36, and the 1st-3rd chemical | medical valve Although 37, 38, and 39 are provided, other configurations may be used. For example, the number, arrangement, and denitration drug of the first to third spray nozzles 31, 32, 33, the first to third denitration drug supply pipes 34, 35, 36, and the first to third drug valves 37, 38, 39. The amount of blowing 20 can be changed according to the size, performance, etc. of the incinerator 14.

  And in the said embodiment, the nitrogen oxide density | concentration detector 45 is provided in the chimney entrance part, This nitrogen oxide density | concentration detector 45 detects the nitrogen oxide density | concentration N in the combustion exhaust gas 21 discharge | released from a chimney, and this Denitration that is blown into the secondary combustion chamber 17 and the blowing position and amount of the combustion exhaust gas 19 blown into the primary combustion chamber 16 so that the nitrogen oxide concentration N emitted from the chimney becomes a preset concentration NS. You may make it control the blowing position and blowing amount of the chemical | medical agent 20. FIG. Thereby, even when the properties of the waste 5 change or the supply amount of the waste 5 supplied to the primary combustion chamber 16 fluctuates, the nitrogen oxide concentration N in the combustion exhaust gas 21 discharged from the chimney is previously set. Control can be performed so that the density NS is set.

  As described above, the denitration method for an incinerator and the denitration system for an incinerator according to the present invention reduce the nitrogen oxide concentration in the combustion exhaust gas discharged from the combustion chamber, thereby reducing the nitrogen oxide concentration in the combustion exhaust gas. Therefore, the present invention has an excellent effect that the catalytic reaction equipment for reducing the temperature can be omitted or reduced in size, and is suitable for application to such a denitration method for an incinerator and a denitration system for an incinerator.

5 Waste 14 Incinerator 15 Denitration System of Incinerator 16 Primary Combustion Chamber 17 Secondary Combustion Chamber 18 Combustion Chamber 19 Circulating Combustion Exhaust Gas 20 Denitration Agent 21 Combustion Exhaust Gas 22 Primary Air 23 Secondary Air 24 Stoker 25 Primary Air Supply Port 26 Secondary air supply port 27 First to third exhaust gas recirculation gas pipe 28 First to third gas supply port 29 First to third gas valve 30 Control unit 31 First spray nozzle 32 Second spray nozzle 33 Third spray nozzle 34 First denitration drug supply pipe 35 Second denitration drug supply pipe 36 Third denitration drug supply pipe 37 First drug valve 38 Second drug valve 39 Third drug valve 40 Gas flow direction 41 First temperature detector 42 Second temperature detector 43 Third temperature detector 44 Fourth temperature detector 45 Nitrogen oxide concentration detector 46 Exhaust gas recirculation facility

Claims (6)

By blowing primary air and secondary air into the primary combustion chamber stoker combustion chamber is provided, relative to the primary combustion chamber of the incinerator to be incinerated by burning waste after combustion in the combustion chamber In a denitration method for an incinerator that blows combustion exhaust gas and blows denitration chemicals into a secondary combustion chamber of the combustion chamber that is a flue extending from the primary combustion chamber ,
The position of blowing the denitration agent into the combustion chamber, the primary air into the combustion chamber, Ri downstream der gas flow direction than the position of blowing secondary air, and combustion exhaust gas,
Wherein A plurality of gas supply ports are provided at positions different from each other in the primary combustion chamber, and characterized that you adjust the blowing rate of the combustion exhaust gas is blown into the primary combustion chamber from each of the plurality of gas supply ports Denitration method for incinerators. The combustion chamber is provided with a plurality of temperature detectors for detecting the temperature in the combustion chamber, and a plurality of denitration agent blowing parts for blowing denitration agent,
A denitration agent provided at a spatial position of the measurement temperature having a high denitration efficiency obtained from the relationship between the temperature and the denitration efficiency based on the measured temperatures detected by the plurality of temperature detectors, corresponding to the spatial position. The denitration method for an incinerator according to claim 1, wherein a denitration chemical is blown from the blowing section.   The denitration method for an incinerator according to claim 2, wherein the spatial position of the measurement temperature with high denitration efficiency is a spatial position within a range of the measurement temperature of 800 to 1000 ° C.   The combustion exhaust gas blown into the combustion chamber is a part of the processed combustion exhaust gas processed by the exhaust gas treatment facility, and the remaining combustion exhaust gas is denitrated by the catalytic reaction facility. A denitration method for an incinerator according to any one of the above.   5. The denitration method for an incinerator according to claim 4, wherein leaked ammonia resulting from the denitration chemical blown into the combustion chamber is used for a catalytic reaction in the catalytic reaction facility. By blowing primary air and secondary air into the primary combustion chamber stoker combustion chamber is provided, in the primary combustion chamber of the incinerator to be incinerated by burning waste, the combustion exhaust gas after combustion in the combustion chamber In a denitration system of an incinerator that denitrates by blowing a denitration chemical into a secondary combustion chamber of the combustion chamber, which is a flue extending from the primary combustion chamber ,
The position of blowing the denitration agent into the combustion chamber, the primary air into the combustion chamber, Ri downstream der gas flow direction than the position of blowing secondary air, and combustion exhaust gas,
A plurality of gas supply ports provided at different positions in the primary combustion chamber for blowing the combustion exhaust gas into the primary combustion chamber, and a plurality of recirculation gas pipes connected to each of the plurality of gas supply ports When denitration system incinerator characterized by Rukoto comprises a plurality of adjusting valves provided to each of the plurality of recirculation gas pipe, and a control unit for controlling the plurality of control valve.

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