JP6149048B2 - Waste treatment system and operation method thereof - Google Patents

Description

  The present invention relates to a waste treatment system for treating waste and an operation method thereof.

  Conventionally, a gasification furnace that takes out combustible gas from waste, a melting furnace that melts ash contained in the combustible gas, and a melting furnace post-stage facility (boiler or other) disposed on the downstream side (downstream side) of the melting furnace And a waste treatment system including a temperature reduction tower or the like. Combustion air for burning the combustible gas flowing in from the gasification furnace is supplied to the melting furnace. Thereby, combustible gas burns and the inside of a melting furnace becomes high temperature, so that the ash contained in the combustible gas is effectively melted. For example, Patent Document 1 discloses a gasification furnace, a melting furnace having an inlet that allows inflow of combustible gas generated in the gasification furnace, and a combustion air supply nozzle that supplies combustion air into the melting furnace. And a waste treatment system comprising: The melting furnace has a combustion chamber having a shape extending in the vertical direction, and the inflow port is formed in the upper portion of the combustion chamber. The combustion air supply nozzle is arranged in a posture capable of supplying combustion air from the inlet to the combustion chamber. It is preferable that the combustion air is supplied from the inlet at a flow rate as large as possible. In this way, the combustible gas is burned in the vicinity of the inlet by promoting the mixing of the combustible gas and the combustion air in the vicinity of the inlet, that is, the vicinity of the inlet is at a high temperature. Therefore, the ash is effectively melted.

JP 2009-014334 A

  In the waste treatment system described in Patent Document 1, when the combustion air is supplied into the melting furnace through the inlet at a relatively large flow rate, the latter stage of the melting furnace disposed on the rear stage side of the melting furnace Equipment (boilers, cooling towers, etc.) may vibrate.

  An object of the present invention is to provide a waste treatment system capable of suppressing vibrations of a melting furnace latter-stage equipment disposed on the rear stage side of the melting furnace and an operating method thereof.

  As a result of intensive studies to solve the above problems, the present inventors have repeatedly increased and decreased the pressure of exhaust gas discharged from the melting furnace (pulsating), and the frequency of this pressure fluctuation and the melting It has been found that when the natural frequency of the furnace post-stage equipment substantially coincides, the post-melting furnace equipment vibrates significantly. For this reason, it is desirable to control the frequency of the exhaust gas pressure fluctuation in a range different from the natural frequency of the latter equipment of the melting furnace in order to suppress the vibration of the latter equipment of the melting furnace, but this control is very difficult. is there. The reason for this is as follows. That is, the fluctuation of the pressure of the exhaust gas is presumed to be caused by the fact that the ignition position of the combustible gas in the melting furnace repeats the up and down transition, and the cycle of the transition of the ignition position is controlled. Because it is very difficult.

  Therefore, the present inventors reduced the amplitude of the exhaust gas pressure fluctuation (the peak pressure of the component having a frequency substantially equal to the natural frequency of the latter equipment of the melting furnace in the waveform indicating the transition of the exhaust gas pressure). The idea was to reduce the vibration of the latter equipment of the melting furnace. And it discovered that the reduction of the said amplitude was implement | achieved by reduction of the fluctuation range of the ignition position of the combustible gas in a melting furnace. Further, by suppressing the combustion of the combustible gas in the vicinity of the inlet, that is, by suppressing the mixing of the combustible gas and the combustion gas in the vicinity of the inlet, the ignition position of the combustible gas. It has been found that the fluctuation range of the ignition position becomes smaller as the gas moves downward from the vicinity of the inlet. As a means for suppressing the mixing, it is conceivable to reduce the supply amount of combustion air to the vicinity of the inlet, but if the total supply amount of combustion air to the melting furnace decreases, the air in the combustion chamber The ratio is lowered, and it is difficult to combust effective flammable gas (melting of ash) in the combustion chamber.

  Therefore, the present inventors reduced the flow rate of the combustion air supplied to the vicinity of the inlet while maintaining the total amount of combustion air supplied to the combustion chamber, thereby effectively melting and melting the ash. It was conceived that both the reduction of the vibration of the post-furnace equipment can be achieved.

  The present invention has been made from this point of view, and is a waste treatment system for treating waste, and the ash contained in the combustible gas is burned by burning the combustible gas generated in the gasification furnace. A melting furnace for melting, an air supply unit capable of supplying combustion air for burning the combustible gas into the melting furnace, a melting furnace rear-stage facility disposed on the rear side of the melting furnace, and the air A control unit that controls a mode of supplying the combustion air into the melting furnace by a supply unit, and the melting furnace has an inlet that allows inflow of the combustible gas, and through the inlet A combustion chamber for combusting inflowing combustible gas; and the air supply unit includes an inlet vicinity supply unit capable of supplying the combustion air toward the vicinity of the inlet, and the control unit includes the control unit The latter stage of the melting furnace When the vibration condition indicating that it has moved is not satisfied, the combustion air is supplied toward the vicinity of the inlet from the inlet vicinity supply section, and when the vibration condition is satisfied in the state, The vibration condition is satisfied with respect to the flow velocity of the combustion air supplied by the supply unit near the inlet while maintaining the same supply amount as the total supply amount of the combustion air into the combustion chamber when the vibration condition is not satisfied. Provided is a waste treatment system that reduces the flow velocity of combustion air supplied by the supply unit near the inlet when not.

  In the present invention, when the vibration condition is satisfied, the combustion supplied to the vicinity of the inlet while maintaining the same supply amount as the total supply amount of combustion air into the combustion chamber when the vibration condition is not satisfied. Since the flow velocity of the working air is lower than the flow velocity of the combustion air supplied by the supply unit near the inlet when the vibration condition is not satisfied, the effective melting of the ash content and the vibration of the latter stage equipment of the melting furnace are reduced. Both are achieved. Specifically, since the decrease in the air ratio in the combustion chamber is suppressed by maintaining the total supply amount of the combustion air before and after the vibration condition is satisfied, effective combustion of the combustible gas in the combustion chamber is prevented. Maintained, which effectively melts the ash. Further, when the vibration condition is satisfied, the flow velocity of the combustion air supplied to the vicinity of the inlet is higher than the flow velocity of the combustion air supplied from the inlet vicinity supply portion when the vibration condition is not satisfied. By lowering, mixing of the combustible gas and the combustion air in the vicinity of the inlet is suppressed, so that combustion of the combustible gas in the vicinity of the inlet is suppressed. As a result, the ignition position of the combustible gas in the combustion chamber moves downward, and the fluctuation range of the ignition position becomes smaller. For this reason, since the amplitude of the pressure fluctuation of the exhaust gas discharged from the melting furnace becomes small, even if the frequency of the pressure fluctuation substantially matches the natural frequency of the latter equipment of the melting furnace, the latter equipment of the melting furnace Vibration is reduced.

  In this case, the air supply unit further includes an adjustment air supply unit capable of supplying the combustion air toward a position different from the vicinity of the inlet in the combustion chamber, and the control unit includes the control unit When the vibration condition is not satisfied, the combustion air is supplied only from the inlet vicinity supply portion toward the vicinity of the inlet, and the vibration condition is satisfied when the vibration condition is satisfied in that state. When the supply rate is the same as the total supply amount of the combustion air into the combustion chamber when the combustion condition is not satisfied, and the flow rate of the combustion air supplied by the inlet vicinity supply unit does not satisfy the vibration condition Preferably, the combustion air is supplied into the combustion chamber from the inlet vicinity supply section and the adjustment air supply section so that the flow velocity is lower than the flow velocity of the combustion air supplied by the inlet vicinity supply section. Arbitrariness.

  In this way, it is possible to control the mixed state more broadly than in the case where the mixed state of the combustible gas and the combustion air in the vicinity of the inlet is controlled only by the inlet vicinity supply unit. Become. The control of the mixed state only by the inlet vicinity supply section, that is, the control of the flow velocity of the combustion air supplied toward the vicinity of the inlet is achieved, for example, by increasing or decreasing the cross-sectional area of the inlet vicinity supply section. Although possible, there is a limit to the control range (range of increase / decrease in cross-sectional area). On the other hand, in the present invention, the proportion of the combustion air supplied from the regulated air supply unit mixed with the combustible gas is such that the combustion air supplied from the inlet vicinity supply unit is mixed with the combustible gas. Since the ratio is lower than the ratio, the combined state can be controlled by combining the vicinity of the inlet and the adjusted air supply unit, compared to the case where the mixed state is controlled only by the vicinity of the inlet. . Specifically, the combustion air supplied from the inlet vicinity supply section is well mixed with the combustible gas in the vicinity of the inlet in the combustion chamber, while the combustion air supplied from the regulated air supply section. Flows from a position different from the inlet, that is, from a position different from the position where the flammable gas flows into the combustion chamber, toward the position in the combustion chamber that is different from the vicinity of the inlet. The mixing property between air and combustible gas is lower than the mixing property between combustion air and combustible gas supplied from the inlet vicinity supply unit. For this reason, it becomes possible to control the said mixed state widely by combining an inflow port vicinity supply part and a regulated air supply part.

  Specifically, the inlet vicinity supply part supplies the combustion air horizontally toward the vicinity of the inlet, and the adjustment air supply part is a position where the inlet is provided in the combustion chamber. It is preferable to supply the combustion air horizontally from the same height position toward a position in the combustion chamber that is different from the vicinity of the inlet.

  If it does in this way, the broad control of the said mixed state and suppression of the rapid fall of the temperature of the vicinity of the said inflow port are compatible. For example, when the adjustment air supply unit supplies combustion air into the combustion chamber from a height position different from the position where the inlet is provided in the combustion chamber, the vicinity of the inlet of the combustion air and the combustible gas As the mixing at this point is hardly promoted, the temperature in the vicinity of the inflow port may drop rapidly. If it does so, the melting amount of the ash content contained in combustible gas will fall rapidly. On the other hand, in the present invention, the inlet vicinity supply part supplies combustion air horizontally toward the vicinity of the inlet, and the adjusted air supply part is the same as the position where the inlet is provided in the combustion chamber. Since combustion air is supplied horizontally from a height position toward a position in the combustion chamber that is different from the vicinity of the inlet, the combustion air and the combustible gas in the vicinity of the inlet are compared with the above case. As a result, the mixing state is improved, and a rapid decrease in temperature in the vicinity of the inlet is thereby suppressed.

  Further, in this case, the inlet vicinity supply unit includes a first nozzle arranged in a posture capable of supplying the combustion air horizontally toward the vicinity of the inlet, and the adjustment air supply unit includes: A second nozzle disposed in a posture capable of supplying the combustion air horizontally from a portion of the combustion chamber spaced apart from the inlet to a position different from the vicinity of the inlet in the combustion chamber; The combustion air can be supplied horizontally from a portion of the combustion chamber far from the portion where the second nozzle is disposed from the inlet toward a position different from the vicinity of the inlet in the combustion chamber. And the control unit supplies the combustion air from only the first nozzle toward the vicinity of the inflow port when the vibration condition is not satisfied. Let that state In this case, when the vibration condition is satisfied, the same supply amount as the total supply amount of the combustion air into the combustion chamber when the vibration condition is not satisfied is maintained and the combustion supplied by the first nozzle The combustion from the first nozzle and the second nozzle into the combustion chamber so that the flow velocity of the working air is lower than the flow velocity of the combustion air supplied by the first nozzle when the vibration condition is not satisfied. The combustion air into the combustion chamber when the other vibration condition is not satisfied when the other vibration condition is satisfied when the working air is supplied and the latter stage equipment of the melting furnace is vibrated in that state. When the same supply amount as the total supply amount of air is maintained and the flow velocity of the combustion air supplied by the first nozzle and the second nozzle does not satisfy the other vibration condition, the first nozzle and the first nozzle 2 Le As becomes lower than the flow velocity of the combustion air supply, the first nozzle, it is possible to supply the combustion air from the second nozzle and third nozzle toward the combustion chamber preferred.

  In this way, the temperature in the vicinity of the inlet decreases stepwise according to the vibration of the melting furnace latter-stage equipment. Therefore, the vibration in the latter stage of the melting furnace is effectively maintained while maintaining the vicinity of the inlet as high as possible. Can be reduced. Specifically, when the combustion air is supplied from the first nozzle and the second nozzle only when the combustion air is supplied only from the first nozzle, the combustion air and the combustible gas near the inflow port In addition, in the case where the combustion air is supplied from the first nozzle, the second nozzle, and the third nozzle, the mixing is suppressed rather than the case, so that the mixing is suppressed according to the vibration of the latter equipment of the melting furnace. As a result, the temperature in the vicinity of the inlet decreases gradually.

  The present invention further includes a duct for introducing the combustible gas generated in the gasification furnace into the melting furnace, wherein the combustion chamber has a cylindrical inner peripheral surface and a central axis thereof is vertical. And the duct forms a swirl flow in which the combustible gas flowing into the combustion chamber through the inflow port of the combustion chamber swirls along the inner peripheral surface of the combustion chamber Connected to the combustion chamber, and the second nozzle and the third nozzle are connected to the combustion chamber in such a manner that the combustion air supplied from the second nozzle and the third nozzle follows the swirl flow. It is preferable that

  In this way, since the combustion air and the combustible gas form a swirling flow that swirls along the circumferential direction of the combustion chamber in the vicinity of the inlet, the inlet of the combustion air and the combustible gas is formed. The residence time in the vicinity of becomes longer. Therefore, a rapid decrease in temperature near the inlet is suppressed.

  In addition, the present invention has an inlet that allows inflow of combustible gas generated in the gasification furnace, a melting furnace that melts ash contained in the combustible gas flowing in through the inlet, and the melting furnace An operation of a waste treatment system comprising a melting furnace latter-stage facility disposed on the latter stage side, wherein air supply for supplying combustion air for burning the combustible gas toward the vicinity of the inflow port A step of supplying the combustion air toward the vicinity of the inflow port when a vibration condition indicating that the latter equipment of the melting furnace vibrates is not satisfied in the air supply step, When the vibration condition is satisfied, supply toward the vicinity of the inlet while maintaining the same supply amount as the total supply amount of the combustion air into the melting furnace when the vibration condition is not satisfied Than the flow velocity of the combustion air supplied toward the vicinity of the inlet when the flow rate of burnt air said vibration condition is not satisfied decreases to provide a method of operating waste treatment system.

  Also in this method, effective melting of ash in the melting furnace and reduction of vibration of the latter equipment of the melting furnace are achieved.

  As described above, according to the present invention, it is possible to provide a waste treatment system capable of suppressing the vibration of the melting furnace latter-stage equipment disposed on the latter stage side of the melting furnace and the operating method thereof.

It is a figure which shows the outline of the gasification melting furnace of one Embodiment of this invention. It is sectional drawing in the II-II line | wire of FIG. It is a flowchart which shows the control content of a control part. It is a figure which shows the example of the fluctuation range of the ignition position of combustible gas. It is a figure which shows the example of the fluctuation range of the ignition position of combustible gas.

  A waste treatment system according to an embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the waste treatment system of the present embodiment includes a gasification furnace 100, a melting furnace 200, a duct 110 that connects the gasification furnace 100 and the melting furnace 200, an air supply unit 300, and The boiler 400, the temperature reducing tower 500, the bag filter 600, the chimney 700, the vibration detector 800, and the control unit 900 are provided.

  The gasification furnace 100 is a furnace that takes out combustible gas from the waste by heating the waste. In this embodiment, a fluidized bed gasifier is used as the gasifier 100. Specifically, the fluidized bed gasification furnace is a furnace that takes out combustible gas from the waste by heating the waste in a fluidized bed formed by fluidizing the fluidized medium with the fluidized gas. . The combustible gas generated in the gasification furnace 100 flows into the melting furnace 200 through the duct 110.

  The melting furnace 200 is a furnace for melting the ash contained in the combustible gas by burning the combustible gas generated in the gasification furnace 100. In the present embodiment, a swirling flow melting furnace is used as the melting furnace 200. The melting furnace 200 has a primary combustion chamber 210 and a secondary combustion chamber 220. Combustion air (primary air) for burning the combustible gas is supplied to the primary combustion chamber 210 by the air supply unit 300, and exhaust gas generated in the primary combustion chamber 210 is supplied to the secondary combustion chamber 220. Secondary air for further combustion is supplied. Between the primary combustion chamber 210 and the secondary combustion chamber 220, a tap outlet 230 is formed that can discharge molten slag formed by melting of ash downward.

  The primary combustion chamber 210 has an inflow port 211a that allows inflow of combustible gas, and combusts the swirling combustible gas that has flowed through the inflow port 211a. The inflow port 211a is formed in a circular shape. The primary combustion chamber 210 has a shape extending in the vertical direction. The primary combustion chamber 210 includes an upstream combustion chamber 211 having an inflow port 211a, a downstream combustion chamber 212 disposed below the upstream combustion chamber 211, an upstream combustion chamber 211, and a downstream combustion chamber 212. And an aperture 213 provided at the boundary.

  The upstream combustion chamber 211 is formed in a cylindrical shape and is arranged in a posture in which the central axis is parallel to the vertical. The inflow port 211a is formed in the upper part of the upstream combustion chamber 211. The duct 110 is connected to a portion of the upstream combustion chamber 211 that surrounds the inflow port 211a. As shown in FIG. 2, the duct 110 forms a swirl flow in which combustible gas flowing into the upstream combustion chamber 211 through the inlet 211 a swirls along the inner peripheral surface of the upstream combustion chamber 211. Is connected to the upstream combustion chamber 211. Specifically, the duct 110 is connected to the upstream combustion chamber 211 in a posture in which a combustible gas flows into the upstream combustion chamber 211 in a direction different from the center of the upstream combustion chamber 211 from the inflow port 211a. Yes.

  The downstream combustion chamber 212 has a bottom wall having a shape extending obliquely downward from below the throttle portion 213. The molten slag flows down on the bottom wall and is discharged from the outlet 230. The throttle portion 213 has an inner diameter that is smaller than the inner diameter of the lower end portion of the upstream combustion chamber 211.

  The secondary combustion chamber 220 further burns the exhaust gas after burning in the primary combustion chamber. The secondary combustion chamber 220 is disposed on the opposite side (downstream side) of the primary combustion chamber 210 with respect to the tap outlet 230. The secondary combustion chamber 220 has a shape surrounding a space extending obliquely upward from the tap outlet 230.

  The air supply unit 300 supplies combustion air for burning the combustible gas into the primary combustion chamber 210. The air supply unit 300 includes a combustion air supply source (not shown), an inlet vicinity supply unit 310, and a regulated air supply unit 320. Each supply part 310,320 is connected to the said combustion air supply source via piping. In the present embodiment, the combustion air supply source supplies a specific amount (a constant amount) of combustion air.

  The inlet vicinity supply part 310 supplies combustion air toward the vicinity S of the inlet 211a. Here, “the vicinity S of the inflow port 211a” means that the center of the upstream combustion chamber 211 is parallel to the central axis of the portion of the duct 110 connected to the upstream combustion chamber 211 as shown in FIG. A region surrounded by a first straight line L1 passing through O, a second straight line L2 orthogonal to the first straight line L1 and passing through the center O of the upstream combustion chamber 211, and the inlet 211a. In this embodiment, the inlet vicinity supply part 310 supplies combustion air toward the vicinity S of the inlet 211a in the upstream combustion chamber 211 through the inlet 211a. The inlet vicinity supply unit 310 includes a plurality of (ten in the present embodiment) first nozzles 311. Each first nozzle 311 supplies (injects) combustion air supplied from the combustion air supply source into the duct 110. As shown in FIG. 2, each first nozzle 311 is connected to the duct 110 so as to penetrate the duct 110. In the present embodiment, five first nozzles 311 are connected to each of the right part and the left part of the duct 110 in plan view (FIG. 2). The number of first nozzles 311 is not limited to this example. The first nozzles 311 connected to the right part of the duct 110 are arranged in a vertically overlapping manner, and the first nozzles 311 connected to the left part of the duct 110 are arranged in the vertical direction. They are lined up in an overlapping position. Each first nozzle 311 is connected to the duct 110 in a posture that is horizontal and capable of supplying combustion air toward the inflow port 211a.

  The air supply unit 300 includes a plurality of first on-off valves V1 provided in a pipe connecting the combustion air supply source and the first nozzles 311. The supply and stop of combustion air from the first nozzle 311 are switched by opening and closing the first on-off valve V1. Combustion air supplied from the first nozzle 311 flows into the upstream combustion chamber 211 from the inflow port 211a together with the combustible gas, and forms a swirl flow (a counterclockwise swirl flow in FIG. 2). For this reason, combustion air and combustible gas are mixed in the vicinity S of the inflow port 211a. Thereby, combustible gas burns and the primary combustion chamber 210 becomes high temperature, so that the ash contained in the combustible gas melts. The slag formed by the melting of the ash flows out from the tap outlet 230.

  The adjusted air supply unit 320 supplies combustion air from a position different from the inlet 211a toward a position different from the vicinity S of the inlet 211a in the upstream combustion chamber 211. The adjusted air supply unit 320 includes a plurality of (15 in this embodiment) nozzles 322 and 323. Each nozzle supplies (injects) combustion air supplied from the combustion air supply source into the upstream combustion chamber 211. Three of these nozzles are connected to five portions of the upstream combustion chamber 211 that are separated from each other along the circumferential direction of the upstream combustion chamber 211. The five portions are set at the same height as the inflow port 211a and at positions spaced apart by an equal distance in the circumferential direction. More specifically, among the five parts, the distance from each of the first and fifth parts located in the circumferential direction from the inlet 211a to the inlet 211a is the remaining three parts (from the inlet 211a). It is set to be shorter than the distance from each of the second, third and fourth portions along the circumferential direction to the inflow port 211a. The nozzles connected to each of the five parts are arranged in a posture that overlaps each other in the vertical direction. Hereinafter, each nozzle connected to two parts (the first and fifth parts located) relatively close to the inflow port 211a among the five parts is referred to as a second nozzle 322, and the five parts Of these nozzles, nozzles connected to three parts relatively far from the inlet 211a (the second, third, and fourth parts) are referred to as third nozzles 323. Each second nozzle 322 and each third nozzle 323 supply combustion air horizontally from the same height position as the inflow port 211a toward a position different from the vicinity S of the inflow port 211a in the upstream side combustion chamber 211. The upstream combustion chamber 211 is connected in a possible posture. The nozzles 322 and 323 are connected to the upstream combustion chamber 211 in a posture inclined by a specific angle θ (see FIG. 2) with respect to the normal line of the upstream combustion chamber 211. The angle θ is set to a value along the swirl flow formed when the combustible gas flows from the inflow port 211a. For this reason, the combustion air supplied from the nozzles 322 and 323 joins the swirl flow.

  The air supply unit 300 includes a plurality of second on-off valves V2 provided in a pipe connecting each second nozzle 322 and the combustion air supply source, each third nozzle 323, and the combustion air supply source. And a plurality of third on-off valves V3 provided in the pipe to be connected. Supply and stop of combustion air from the second nozzle 322 are switched by opening and closing the second on-off valve V2, and supply and stop of combustion air from the third nozzle 323 are switched by opening and closing the third on-off valve V3. It is done.

  The boiler 400 is equipment for extracting power (electric power, etc.) from the exhaust gas by bringing the exhaust gas discharged from the secondary combustion chamber 220 into contact with a heat exchanger or the like. The exhaust gas discharged from the boiler 400 passes through the temperature reducing tower 500. Thereby, the temperature of exhaust gas falls. The exhaust gas flowing out of the temperature reducing tower 500 is appropriately processed by the bag filter 600 and then released from the chimney 700 to the atmosphere. The boiler 400, the temperature reducing tower 500, and the bag filter 600 correspond to “melting furnace latter stage equipment” disposed on the rear stage side of the melting furnace 200.

  The vibration detector 800 is a sensor that can detect vibration. In the present embodiment, an acceleration sensor is used as the vibration detector 800. This acceleration sensor is attached to the wall surface of the boiler 400.

  The control unit 900 controls the supply mode of the combustion air into the primary combustion chamber 210 by the air supply unit 300 according to the detection value of the vibration detector 800, that is, the vibration of the boiler 400. Specifically, the control unit 900 maintains the total supply amount of combustion air into the upstream combustion chamber 211, and the flow velocity of the combustion air supplied by the inlet vicinity supply unit 310 according to the vibration of the boiler 400. Increase or decrease. In the present embodiment, when the vibration condition indicating that the boiler 400 has vibrated is not satisfied, the control unit 900 supplies combustion air only from the inlet vicinity supply unit 310 and the vibration condition is satisfied. The combustion air is supplied from both the inlet vicinity supply unit 310 and the adjusted air supply unit 320. The control unit 900 includes a determination unit 910 and a switching unit 920.

  The determination unit 910 receives the detection value α of the vibration detector 800 and determines whether or not the vibration condition is satisfied. Furthermore, the determination unit 910 is configured to perform another vibration condition (hereinafter referred to as “second vibration condition”) indicating that the boiler 400 is vibrating in a state where the vibration condition (hereinafter referred to as “first vibration condition”) is satisfied. It is determined whether or not “vibration condition” is satisfied.

  The switching unit 920 switches opening / closing of the on-off valves V1, V2, V3 based on the determination result of the determination unit 910.

  Hereinafter, specific control contents of the control unit 900 will be described with reference to FIG.

  When the operation of the waste treatment system is started, the control unit 900 (switching unit 920) opens the first on-off valve V1, and closes the second on-off valve V2 and the third on-off valve V3 (step S11). Thereby, the entire amount of the specific amount of combustion air supplied from the combustion air supply source is supplied only from each first nozzle 311. This combustion air flows into the upstream combustion chamber 211 through the inflow port 211a together with the combustible gas, and forms a swirling flow.

  Thereafter, the control unit 900 (determination unit 910) determines whether or not the first vibration condition is satisfied, that is, the detection value α of the vibration detector 800 is the first reference value within the first period T1 (for example, 1 hour). It is determined whether or not the first reference number N1 times (for example, three times) or more is detected to be α1 or more (step S12). As a result, when the first vibration condition is not satisfied (NO in step S12), the control unit 900 returns to step S11.

  On the other hand, when the first vibration condition is satisfied (YES in step S12), the control unit 900 (switching unit 920) opens the first on-off valve V1 and the second on-off valve V2, and closes the third on-off valve V3. Leave as it is (step S13). Thus, the specific amount of combustion air supplied from the combustion air supply source is distributed and supplied from each first nozzle 311 and each second nozzle 322. That is, the entire supply amount of combustion air is maintained before and after the first vibration condition is satisfied, while the flow velocity of the combustion air supplied from each first nozzle 311 is the first flow rate when the first vibration condition is satisfied. It is lower than that before the one vibration condition is satisfied. Specifically, since a specific amount (a constant amount) of combustion air is continuously supplied from the combustion supply source regardless of whether or not the vibration condition is satisfied, primary combustion is performed before and after the first vibration condition is satisfied. The total amount of combustion air supplied into the chamber 210 is maintained. On the other hand, since the combustion air is supplied from each first nozzle 311 and each second nozzle 322 when the first vibration condition is satisfied, that is, when the first vibration condition is satisfied, it is used as compared with before the condition is satisfied. When the first vibration condition is satisfied, the flow velocity of the combustion air supplied from each first nozzle 311 is lower than that before the first vibration condition is satisfied. . Thereafter, the controller 900 (determination unit 910) determines whether or not the second vibration condition is satisfied, that is, the detection value α of the vibration detector 800 is equal to or greater than the second reference value α2 within the second period T2. It is determined whether or not is detected for the second reference number N2 or more (step S14). As a result, when the second vibration condition is not satisfied (NO in step S14), the control unit 900 returns to step S11 (closes each on-off valve V2). Thereby, the flow velocity of the combustion air supplied from each first nozzle 311 is increased while maintaining the total supply amount of the combustion air. The second period T2, the second reference value α2, and the second reference number N2 are the same values as the first period T1, the first reference value α1, and the first reference number N1, respectively. Or different values.

  On the other hand, when the second vibration condition is satisfied (YES in step S14), the control unit 900 (switching unit 920) opens the first on-off valve V1, the second on-off valve V2, and the third on-off valve V3 (step S15). ). As a result, the specific amount of combustion air supplied from the combustion air supply source is distributed and supplied from each first nozzle 311, each second nozzle 322, and each third nozzle 323. That is, the entire supply amount of combustion air is maintained before and after the second vibration condition is satisfied, whereas the combustion air supplied from each first nozzle 311 and each second nozzle 322 when the second vibration condition is satisfied. The air flow velocity is lower than that before the second vibration condition is satisfied. Thereafter, the control unit 900 (determination unit 910) determines whether or not another vibration condition (hereinafter referred to as “third vibration condition”) indicating that the boiler 400 has vibrated, that is, the third period T3. It is determined whether or not it has been detected that the detected value α of the vibration detector 800 is not less than the third reference value α3 for the third reference number N3 (step S16). As a result, when the third vibration condition is satisfied (YES in step S16), the control unit 900 returns to step S15 (maintains the current state). The third period T3, the third reference value α3, and the third reference number N3 are the same values as the first period T1, the first reference value α1, and the first reference number N1, respectively. Or different values.

  On the other hand, when the third vibration condition is not satisfied (NO in step S16), the controller 900 returns to step S13 (closes each on-off valve V3). Thereby, the flow velocity of the combustion air supplied from each first nozzle 311 and each second nozzle 322 increases while maintaining the total supply amount of the combustion air.

  When the operation of the waste treatment system described above is started, the combustible gas generated in the gasification furnace 100 flows into the primary combustion chamber 210 through the duct 110 and the inlet 211a. At this time, the control part 900 opens only each 1st on-off valve V1. For this reason, a specific amount of combustion air supplied from the combustion air supply source is supplied only from each first nozzle 311, and the combustion air enters the primary combustion chamber 210 through the inflow port 211 a together with combustible gas. Flows in and forms a swirling flow there. That is, since the specific amount of combustion air flows into the primary combustion chamber 210 together with the combustible gas at a relatively high flow rate only through the inflow port 211a, the combustion air and the combustible gas in the vicinity S of the inflow port 211a. Mixing is promoted, and the combustible gas burns effectively. At this time, the ash contained in the combustible gas is melted, and the slag formed thereby flows out from the tap outlet 230.

  Here, in the above state (a state in which combustion gas is supplied only from each first nozzle 311), the pressure of the exhaust gas discharged from the melting furnace 200 repeatedly rises and falls (pulsates). The reason for this is presumed to be that the ignition position of the combustible gas repeats up and down in a range A1 (see FIG. 4) from approximately immediately below the inlet 211a to the throttle 213. . Then, when the frequency of the pressure fluctuation of the exhaust gas substantially matches the natural frequency of the boiler 400, the boiler 400 may shake.

  In the present embodiment, the controller 900 opens each second on-off valve V2 when the first vibration condition indicating that the boiler 400 has vibrated is satisfied. As a result, the combustion air supplied from each first nozzle 311 before the first vibration condition is satisfied while the flow rate of the combustion air supplied from each first nozzle 311 is maintained while the total supply amount of combustion air is maintained. It is lower than the flow rate of working air. Due to the decrease in the flow velocity, mixing of the combustion air and the combustible gas in the vicinity S of the inflow port 211a is suppressed, thereby suppressing the combustion of the combustible gas there. As a result, the ignition position (ignition start position) of the combustible gas moves downward. However, since the total supply amount of the combustion air is maintained before and after the establishment of the first vibration condition, that is, the air ratio of the primary combustion chamber 210 is maintained substantially constant, the combustible gas is at least at the latest. Ignite near the throttle 213. This reason is presumed to be due to the fact that the combustible gas and the combustion air collide with the throttle portion 213 and the combustible gas and the combustion air are mixed in the vicinity of the throttle portion 213. For this reason, as shown in FIG. 5, the fluctuation range A2 of the ignition position of the combustible gas is smaller than the range A1 (see FIG. 4). For this reason, since the amplitude of the pressure fluctuation of the exhaust gas discharged from the melting furnace 200 is reduced, even if the frequency of the pressure fluctuation substantially matches the natural frequency of the boiler 400, the vibration of the boiler 400 is reduced. Reduced. That is, in the present embodiment, effective melting of the ash in the primary combustion chamber 210 by maintaining the total supply amount of the combustion air before and after the establishment of the first vibration condition, and the first nozzle 311 Both reduction of the vibration of the boiler 400 due to the flow velocity of the combustion air supplied from the lowering at the time when the first vibration condition is satisfied than before the condition is satisfied are achieved.

  When the boiler 400 is still vibrating in this state, that is, when the second vibration condition indicating that the boiler 400 has vibrated is satisfied, the control unit 900 opens each third on-off valve V3. Accordingly, the flow rate of the combustion air supplied from each of the first nozzles 311 and each of the second nozzles 322 is lower than that before the second vibration condition is satisfied, while maintaining the total supply amount of the combustion air. To do. Then, the fluctuation range of the ignition position is further reduced. For this reason, the amplitude, that is, the vibration of the boiler 400 is reduced while the effective molten state of the ash is maintained.

  As described above, in the present embodiment, each second on-off valve V2 is opened when the first vibration condition is satisfied, and each third on-off valve V3 is further opened when the second vibration condition is satisfied in that state. Since it opens, mixing with the combustion air and combustible gas in the vicinity S of the inflow port 211a according to the vibration condition of the boiler 400 is suppressed in steps. Specifically, in accordance with the vibration state of the boiler 400, combustion is performed in the order of the third nozzles 323 that are relatively far from the inlet 211a from the second nozzles 322 that are relatively closer to the inlet 211a in the adjusted air supply unit 320. Since the supply start timing of the working air is controlled, for example, combustible gas in the vicinity S of the inflow port 211a compared to the case where each of the third on-off valves V3 is opened instead of each of the second nozzles 322 when the first vibration condition is satisfied. And the deterioration of the mixing property with combustion air are suppressed. That is, the temperature in the vicinity of the inflow port 211a decreases stepwise according to the vibration state of the boiler 400. Therefore, the vibration of the boiler 400 can be effectively reduced while maintaining the vicinity S of the inlet 211a as high as possible (while ensuring a wide melting range of the ash).

  On the other hand, the control unit 900 controls the opening / closing of the on-off valves V1, V2, and V3 so as to increase the flow velocity of the combustion air supplied from the first nozzle 311 as the vibration of the boiler 400 subsides. For this reason, as the vibration of the boiler 400 subsides, the mixing of the combustible gas and the combustion air in the vicinity S of the inflow port 211a is gradually promoted. Therefore, in this embodiment, the vicinity S of the inflow port 211a is kept as high as possible within a range in which the vibration of the boiler 400 is suppressed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, the switching mode of each on-off valve V1, V2, V3 by the switching unit 920 of the control unit 900 is not limited to the above example. That is, the entire supply amount of combustion air is maintained before and after the respective vibration conditions are satisfied, and the flow rate of the combustion air supplied from each first nozzle 311 when the vibration conditions are satisfied satisfies the vibration conditions. If it does not, it should just fall below the flow velocity of the combustion air supplied from each first nozzle 311. For example, the control unit 900 includes five first nozzles 311 connected to the right part of the duct 110 and 5 connected to the left part of the duct 110 when the first vibration condition is not satisfied. Combustion air may be supplied from three of each of the first nozzles 311, and combustion air may be supplied from all the first nozzles 311 when the first vibration condition is satisfied. However, compared to this case (when the mixing state of the combustible gas and the combustion air in the vicinity S of the inlet 211a is controlled only by the inlet vicinity supply unit 310), the supply in the vicinity of the inlet is performed as in the above embodiment. When the unit 310 and the adjusted air supply unit 320 are combined, the mixed state can be controlled more widely. Specifically, the rate at which the combustion air supplied from the regulated air supply unit 320 is mixed with the combustible gas is the rate at which the combustion air supplied from the inlet vicinity supply unit 310 is mixed with the combustible gas. Compared to the case where the mixing state is controlled only by the inlet vicinity supply unit 310, the mixing state can be controlled more widely by combining the inlet vicinity supply unit 310 and the regulated air supply unit 320. it can. More specifically, the combustion air supplied from the inlet vicinity supply unit 310 flows into the primary combustion chamber 210 from the inlet 211a together with the combustible gas. While being mixed well, the combustion air supplied from the regulated air supply unit 320 is different from the inlet 211a, that is, from a position different from the position where the combustible gas flows into the primary combustion chamber 210. Since it flows into the primary combustion chamber 210, the mixing ratio of the combustion air and the combustible gas is lower than the mixing ratio of the combustion air and the combustible gas supplied from the inlet vicinity supply unit 310. Become. For this reason, it becomes possible to control the said mixed state widely by combining the inflow port vicinity supply part 310 and the adjustment air supply part 320. FIG. Alternatively, the control unit 900 causes combustion air to be supplied from each first nozzle 311 when the first vibration condition is not satisfied, and all nozzles (each first nozzle) when the first vibration condition is satisfied. Combustion air may be supplied from 311 to each third nozzle 323).

  Alternatively, when the first vibration condition is not satisfied, the control unit 900 sets the opening degree of each first on-off valve V1 to 100% and opens each second on-off valve V2 and each third on-off valve V3. By setting the degree to 0%, combustion air is supplied only from each first nozzle 311 and when the first vibration condition is satisfied, the opening degree of each second on-off valve V2 and each third on-off valve V3 is set. By setting the ratio to 25%, combustion air is also supplied from each second nozzle 322 and each third nozzle 323. When the second vibration condition is satisfied in this state, each second on-off valve V2 and each third nozzle The amount of combustion air supplied from each second nozzle 322 and each third nozzle 323 may be increased by setting the opening degree of the on-off valve V3 to 50%. The opening degree of each second on-off valve V2 and each third on-off valve V3 when the first vibration condition is satisfied, and each second on-off valve V2 and each second opening when the second vibration condition is satisfied. The opening degree of the 3 on-off valve V3 is not limited to the above value as long as the latter is larger.

  Alternatively, when the first vibration condition is not satisfied, the control unit 900 sets the opening degree of each first on-off valve V1 to 100% and opens each second on-off valve V2 and each third on-off valve V3. By setting the degree to 0%, combustion air is supplied only from each first nozzle 311 and when the first vibration condition is satisfied, the opening degree of each second on-off valve V2 and each third on-off valve V3 is set. By setting the ratio to 25%, combustion air is also supplied from each of the second nozzles 322 and each of the third nozzles 323. When the second vibration condition is satisfied in this state, the inlet 211a of each of the third nozzles 323 is satisfied. Only the supply amount of the combustion air supplied from the third adjustment nozzle located farthest from the control nozzle may be increased. For example, when the second vibration condition is satisfied, the control unit 900 increases the opening degree of the third on-off valve V3 provided in the pipe connected to the adjustment third nozzle to be greater than 25% and 75%. The following values may be set.

  Further, in the above-described embodiment, the example in which the control unit 900 returns to step S11 when NO in step S14 is shown. However, in the case of NO in step S14, vibration detection is performed within a predetermined period after step S13. When the detected value α of the device 800 is detected to be equal to or greater than a predetermined reference value a predetermined number of times or more, the control unit 900 may return to Step S13.

  Further, the position where the first nozzle 311 is connected is not limited to the duct 110 as long as combustion air can be supplied toward the vicinity S of the inflow port 211a. For example, the upstream combustion chamber 211 may be connected to a portion between the inlet 211a and the portion to which the second nozzle 322 is connected.

  Further, the number of the nozzles 322 and 323 of the adjusted air supply unit 320 is not limited to the above example. The adjusted air supply unit 320 only needs to have at least one nozzle. Further, the position where the adjusted air supply unit 320 is provided is not limited to the above example (the same height position as the inflow port 211a in the upstream combustion chamber 211). The adjusted air supply unit 320 may be provided at any position where the combustion air can be supplied from a position different from the inlet 211a toward a position different from the vicinity S of the inlet 211a in the primary combustion chamber 210. Is possible. For example, the adjusted air supply unit 320 may be connected to the top of the primary combustion chamber 210 in a posture capable of supplying combustion air downward. However, the adjusted air supply unit 320 (the second nozzle 322 and the third nozzle 323) flows in the primary combustion chamber 210 from the same height position as the position where the inflow port 211a is provided as in the above embodiment. It is preferable to connect to the primary combustion chamber 210 in a posture in which combustion air is supplied horizontally toward a position different from the vicinity S of the inlet 211a. In this way, compared with the case where the adjusted air supply unit 320 is connected to the top of the primary combustion chamber 210, the mixing state of the combustion air and the combustible gas in the vicinity S of the inflow port 211a becomes better. . Therefore, a rapid decrease in the temperature in the vicinity S of the inflow port 211a is suppressed.

  Further, the attachment destination of the vibration detector 800 is not limited to the boiler 400. The vibration detector 800 can be attached to any equipment (for example, the temperature-decreasing tower 500) among the latter equipment of the melting furnace.

DESCRIPTION OF SYMBOLS 100 Gasification furnace 110 Duct 200 Melting furnace 210 Primary combustion chamber 211 Upstream combustion chamber 211a Inlet 300 Air supply part 310 Inlet vicinity supply part 311 1st nozzle 320 Adjustment air supply part 322 2nd nozzle 323 3rd nozzle 400 Boiler (after melting furnace)
500 Temperature reduction tower (melting furnace latter stage equipment)
600 Bug filter (melting furnace latter stage equipment)
700 Chimney 800 Vibration detector 900 Control unit V1 First on-off valve V2 Second on-off valve V3 Third on-off valve S Near the inlet

Claims (6)

A waste treatment system for treating waste,
A melting furnace for melting the ash contained in the combustible gas by burning the combustible gas generated in the gasification furnace;
An air supply unit capable of supplying combustion air for burning the combustible gas into the melting furnace;
A melting furnace latter-stage facility disposed on the latter stage side of the melting furnace;
A control unit for controlling a supply mode of the combustion air into the melting furnace by the air supply unit,
The melting furnace has an inflow opening that allows the inflow of the combustible gas, and a combustion chamber for burning the combustible gas that has flowed in through the inflow opening.
The air supply part includes an inlet vicinity supply part capable of supplying the combustion air toward the vicinity of the inlet,
The control unit causes the combustion air to be supplied from the vicinity of the inlet to the vicinity of the inlet when a vibration condition indicating that the latter equipment of the melting furnace vibrates is not satisfied, and the state When the vibration condition is satisfied, the inflow port vicinity supply unit supplies the same supply amount as the total supply amount of the combustion air into the combustion chamber when the vibration condition is not satisfied. A waste treatment system that reduces the flow velocity of combustion air below the flow velocity of combustion air supplied by the inflow port vicinity supply section when the vibration condition is not satisfied. The waste treatment system according to claim 1,
The air supply unit further includes an adjustment air supply unit capable of supplying the combustion air toward a position different from the vicinity of the inlet in the combustion chamber,
When the vibration condition is not satisfied, the control unit causes the combustion air to be supplied only from the inlet vicinity supply section toward the vicinity of the inlet, and when the vibration condition is satisfied in that state. The flow rate of the combustion air supplied by the supply unit near the inlet is maintained at the same supply amount as the total supply amount of the combustion air into the combustion chamber when the vibration condition is not satisfied. The combustion air is supplied from the vicinity of the inlet and the regulated air supply to the combustion chamber so that the flow velocity is lower than the flow velocity of the combustion air supplied by the vicinity of the inlet when Waste treatment system to supply. The waste treatment system according to claim 2,
The inlet vicinity supply unit supplies the combustion air horizontally toward the vicinity of the inlet,
The adjustment air supply unit horizontally discharges the combustion air from the same height position as the position where the inlet is provided in the combustion chamber toward a position different from the vicinity of the inlet in the combustion chamber. Supply waste treatment system. The waste treatment system according to claim 3,
The inlet vicinity supply part has a first nozzle arranged in a posture capable of supplying the combustion air horizontally toward the vicinity of the inlet,
The adjustment air supply unit is arranged in a posture capable of supplying the combustion air horizontally from a portion of the combustion chamber spaced from the inlet to a position different from the vicinity of the inlet in the combustion chamber. The second nozzle and the portion of the combustion chamber that is farther from the portion where the second nozzle is disposed from the inlet to the position in the combustion chamber that is different from the vicinity of the inlet. A third nozzle arranged in a posture capable of supplying the combustion air,
The control unit supplies the combustion air from only the first nozzle toward the vicinity of the inflow port when the vibration condition is not satisfied, and when the vibration condition is satisfied in the state, The same supply amount as the total supply amount of the combustion air into the combustion chamber when the vibration condition is not satisfied is maintained, and the flow rate of the combustion air supplied by the first nozzle satisfies the vibration condition. The combustion air is supplied from the first nozzle and the second nozzle into the combustion chamber so as to be lower than the flow velocity of the combustion air supplied by the first nozzle when there is not, and the melting furnace is in that state. When other vibration conditions indicating that the subsequent equipment vibrates are satisfied, the same supply amount as the total supply amount of the combustion air into the combustion chamber when the other vibration conditions are not satisfied is maintained. The flow velocity of the combustion air supplied from the first nozzle and the second nozzle is higher than the flow velocity of the combustion air supplied from the first nozzle and the second nozzle when the other vibration condition is not satisfied. A waste treatment system in which the combustion air is supplied from the first nozzle, the second nozzle, and the third nozzle toward the combustion chamber so as to decrease. The waste treatment system according to claim 4,
A duct for introducing the combustible gas generated in the gasification furnace into the melting furnace;
The combustion chamber has a cylindrical inner peripheral surface and is arranged in a posture in which the central axis is parallel to the vertical,
The duct is connected to the combustion chamber in a posture in which a combustible gas flowing into the combustion chamber through the inlet of the combustion chamber forms a swirling flow that swirls along the inner peripheral surface of the combustion chamber,
The waste treatment system, wherein the second nozzle and the third nozzle are connected to the combustion chamber such that combustion air supplied from the second nozzle and the third nozzle follows the swirl flow. A melting furnace that has an inlet that allows inflow of combustible gas generated in the gasification furnace, and that melts ash contained in the combustible gas that has flowed through the inlet;
An operation method of a waste treatment system comprising: a melting furnace latter-stage facility disposed on the latter stage side of the melting furnace,
An air supply step of supplying combustion air for burning the combustible gas toward the vicinity of the inflow port;
In the air supply step, the combustion air is supplied toward the vicinity of the inflow port when a vibration condition indicating that the latter equipment of the melting furnace vibrates is not satisfied, and the vibration condition is satisfied in that state. The combustion air supplied toward the vicinity of the inlet while maintaining the same supply amount as the total supply amount of the combustion air into the melting furnace when the vibration condition is not satisfied. An operation method of a waste treatment system, wherein the flow rate is reduced below the flow rate of combustion air supplied toward the vicinity of the inflow port when the vibration condition is not satisfied.

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