JP6490466B2 - Waste treatment facility and method of operating waste treatment facility - Google Patents

Description

  The present invention relates to a waste treatment facility and a furnace operation method for the waste treatment facility.

  Various sewage is purified by biological treatment using microorganisms and then discharged into rivers or reused. A large amount of sludge generated by such biological treatment is dehydrated and then buried in a final disposal site, or is incinerated or melted.

  FIG. 7 shows a conventional waste treatment facility 100 that incinerates waste such as sludge. The waste treatment facility 100 includes a fluidized bed incinerator 101, a forced air blower 102, a heat exchanger 103 that preheats combustion air supplied by the forced air blower 102 with exhaust heat from the fluidized bed incinerator 101, An exhaust gas treatment facility 104 for purifying exhaust gas generated in the fluidized bed incinerator 101 is provided, and an induction blower 105 for maintaining the inside of the fluidized bed incinerator 101 at a negative pressure is provided downstream of the exhaust gas treatment facility 104. Yes.

  Patent Document 1 discloses a waste treatment system aimed at energy saving. As shown in FIG. 8, the waste treatment system is a sludge treatment system 200 that burns sludge as fuel, and uses a fluidized bed combustion furnace 201 that burns sludge, and combustion gas generated by the combustion furnace 201. And a supercharger 202 that generates and blows compressed air to be supplied to the combustion furnace 201.

  The supercharger 202 includes a turbine 203 driven by exhaust gas discharged from the fluidized bed combustion furnace 201 and purified by the exhaust gas treatment facility 206, and a compressor 204 to which the rotational power of the turbine 203 is transmitted. The compressed air output from 204 is preheated by the heat exchanger 205 and then supplied to the combustion furnace 201 as combustion air, and the inside of the furnace is operated at a positive pressure.

  Patent Documents 2 and 3 provide a waste incineration facility and a processing method that are excellent in energy efficiency without the need for a forced blower for generating compressed air for combustion and compressed air for preventing white smoke and supplying it to the preheater. A waste treatment facility intended to do so is disclosed.

  As shown in FIG. 9, the waste treatment facility 300 is converted into a fluidized bed incinerator 300 by continuous gas-gas heat exchange between the fluidized bed incinerator 301 and the exhaust gas from the fluidized bed incinerator 301. The first preheater 302 that preheats the compressed air for combustion to be supplied, and the turbine 303 is rotated by the compressed air for combustion that is heated by the first preheater 302 toward the fluidized bed incinerator 300, A first supercharger 305 that generates and blows compressed air to be supplied to the first preheater 302 by the compressor 304 and a first turbocharger 305 that is provided upstream of the first preheater 302 and rotates the turbine 303 at the start of operation. 1 start-up air supply device. In addition, a configuration including a generator driven by the power of the first supercharger 305 has been proposed.

Japanese Patent No. 3783024 Japanese Patent No. 4831309 JP 2014-167382 A

  However, in the conventional waste treatment facility 100 shown in FIG. 7, a sufficient amount of combustion air is supplied to the fluidized bed incinerator 101 by the forced air blower 102 against the aeration pressure loss generated in the fluidized bed or the like. Since it is necessary to attract the exhaust gas by the induction fan 105 and maintain the inside of the furnace at a negative pressure, there is a problem that the power cost, that is, the power cost, required for the pusher fan 102 and the induction fan 105 becomes very high.

  The waste treatment system shown in FIG. 8 is configured to pump exhaust gas to the flue with the residual pressure of the compressed air for combustion without installing an induction blower. It is necessary to ensure that high-temperature exhaust gas is not ejected from each exhaust gas treatment facility installed in the system, which increases the equipment cost, and if the seal is broken, high-temperature exhaust gas is ejected. There was a problem that could lead to a serious accident.

  In particular, in principle, it is necessary to increase the pressure between the inlet of the compressor 204 and the inlet of the turbine 203. If an abnormality occurs in this part, combustion exhaust gas may blow out, which may cause a serious accident or disaster. In addition, it is necessary to use a dust remover having heat resistance corresponding to high-temperature exhaust gas, and there is a problem that the equipment cost increases accordingly.

  Furthermore, in the waste treatment facility 300 disclosed in Patent Documents 2 and 3, even if the air compressed by the compressor is preheated by a preheater and supplied as combustion air, the fluidized bed has a large airflow pressure loss, so that the turbine is sufficient. Expansion work could not be obtained, and combustion air could not be blown into the fluidized bed incinerator. Although it is conceivable to increase the preheating amount of the combustion air with a preheater, as a result, an expensive heat-resistant turbine or preheater must be used, which is not practical.

  Further, in the waste treatment facility described in Patent Document 2, it is necessary to introduce start-up air into the air passage that has become high pressure by the compressor of the supercharger when the furnace is started up. As a result, there is a problem that the equipment cost and the power cost increase. In addition, the equipment configuration is complicated to prevent backflow to the compressor side and to eliminate the shut-off air associated therewith, and there is also a problem that a complicated operation is required at startup.

  In view of the above-described problems, an object of the present invention is to provide a waste treatment facility capable of operating a furnace with reduced power cost required for a forced blower and a method for operating the waste treatment facility.

In order to achieve the above-mentioned object, the first characteristic configuration of the waste treatment facility according to the present invention is a fluidized bed furnace for incinerating waste such as sludge, as described in claim 1 of the claims. A waste treatment facility equipped with a heat treatment furnace including a shaft furnace, wherein the first heat exchanger preheats combustion air by the heat of combustion in the furnace of the heat treatment furnace and / or the retained heat of exhaust gas guided to the flue A turbocharger including: a turbine that is rotated by combustion air preheated by the first heat exchanger; and a compressor that supplies combustion air to the first heat exchanger by rotation of the turbine; and the compressor a pusher fan supplies precompressed combustion air to a bypass air passage that bypasses the first heat exchanger, provided in the bypass air passage, heating the combustion air for ventilating the bypass airflow path There in that it includes that and a hot-air furnace, the.

  Since the combustion air pre-compressed by the forced air blower is supplied to the compressor via the air passage, the air compressed not only by the compressor but also by the forced air blower is preheated by the first heat exchanger. In other words, since the compression work by the forced air blower is increased to the compression work by the compressor, the combustion air can be sufficiently supplied even if a loss such as a ventilation pressure loss generated when supplying the combustion air to the heat treatment furnace is subtracted. Can do. In addition, since the power of the forced blower required for this is suppressed by the action of the combustion air through the supercharger and the first heat exchanger, the operating cost can be reduced as a whole.

By the way, when the heat treatment furnace is started, waste heat of the furnace cannot be used, and pressure loss due to ventilation of the air passage or the heat exchanger also occurs. However, by bypassing the first heat exchanger at the start of the heat treatment furnace, the air blowing path can be shortened, and the combustion air is heated by the hot air furnace provided in the bypass air passage so that the heat supply to the turbine and the heat treatment are performed. The furnace can be heated. In addition, since the preheated air temperature can be adjusted by adjusting the air flow rate to the bypass air passage even after the heat treatment furnace is started up, the amount of pressure increase by the turbocharger and the heat treatment furnace temperature can be adjusted. Become.

  In addition to the first characteristic configuration described above, the second characteristic configuration is the same as that described in claim 2, and the first heat exchanger is configured to reduce combustion air by the retained heat of the exhaust gas guided to the flue. A second heat exchanger is arranged in the flue in parallel or in series with the first heat exchanger, and combustion air exhausted from the turbine is further removed by the second heat exchanger. An air supply path for supplying the heat treatment furnace after preheating is provided.

  By further preheating the combustion air discharged from the turbine with the second heat exchanger, the combustion temperature in the furnace can be maintained without supplying a large amount of fossil fuel to the burner and heating it. The consumption of fossil fuel can be reduced.

  In addition to the first or second characteristic configuration described above, the third characteristic configuration is the above-described first or second characteristic configuration, so that the supply amount of combustion air to the heat treatment furnace becomes a target amount. It is in the point further provided with the control part which controls the number of rotations of a forced air blower.

  Since the compression work by the compressor is used, it is not necessary to supply combustion air at a pressure higher than the ventilation pressure loss generated in the heat treatment furnace only by the forced blower, and by controlling the rotational speed of the forced blower by the control unit, Adjust the supply amount of combustion air to the target amount. As a result, it is not necessary to employ a configuration with high power cost such as providing a resistance such as a damper mechanism to adjust the supply amount. Even when the furnace is started up, it is not necessary to perform special control different from that after the start up.

  In the fourth feature configuration, as described in claim 4, in addition to the third feature configuration described above, the control unit is configured to control the target amount based on at least an oxygen concentration contained in the exhaust gas of the heat treatment furnace. The point is that it is configured to set.

  Usually, an air amount required for complete combustion is set based on a theoretical air amount assumed in advance, and a reference oxygen concentration remaining in the exhaust gas is set at that time. Combustion by the control unit so as to decrease the target air amount when the oxygen concentration of the exhaust gas detected by the oxygen gas sensor Sg is higher than the reference oxygen concentration and to increase the target air amount when the oxygen concentration of the exhaust gas is lower than the reference oxygen concentration The supply amount of irrigation air is adjusted up or down. In other words, by using the oxygen concentration contained in the exhaust gas of the heat treatment furnace as an index, an appropriate amount of combustion air can be grasped for the organic components of the sludge combusted in the heat treatment furnace, and the target amount is determined based on the index. Since it is set, it becomes possible to supply the combustion air without greatly exceeding the required amount.

The fifth characterizing feature of the can, as noted in the claim 5, in addition the first above the fourth one characteristic feature of the, and a attractant blower withdrawing gas from the previous SL heat treatment furnace In the point.

  According to the above configuration, the furnace can be safely operated while maintaining the inside of the furnace at a negative pressure.

Characteristic feature of the furnace operation method of waste disposal plant according to the invention, the as described in claim 6, waste and a heat treatment furnace comprising a fluidized bed furnace and a shaft furnace for incineration of waste sludge, such as A furnace operation method for a processing facility, wherein a compression step of compressing combustion air pre-compressed by a forced blower with a compressor, and combustion air compressed in the compression step, A preheating step for preheating by the retained heat of the exhaust gas guided to the flue, a compression power generation step for rotating the turbine with combustion air preheated in the preheating step and transmitting power to the compressor, and the compression power generation the combustion air and the combustion air supply step of supplying to the heat treatment furnace exhausted from the turbine in step, at start of at least the heat treatment furnace, a compressed combustion in the compression step Mind, the preheating step led to the bypass air passage bypassing the, in that it includes a second preheating step of preheating in a hot air furnace provided with the bypass airflow path.

As described in claim 7 , the second characteristic configuration includes, in addition to the first characteristic configuration described above, combustion air exhausted from the turbine in the compression power generation step in the furnace of the heat treatment furnace. A second preheating step of preheating again with combustion heat and / or retained heat of exhaust gas guided to the flue, and supplying the combustion air preheated again in the second preheating step to the combustion air supply step It is in.

In the third feature configuration, as described in claim 8 , in addition to the first or second feature configuration described above, the combustion air pre-compressed by the forced air blower becomes a target air amount. It is in the point further provided with the pushing air blower control process which controls the rotation speed of the said pushing air blower.

  As described above, according to the present invention, it is possible to provide a waste treatment facility capable of operating a furnace with reduced power cost required for a forced blower and a method for operating the waste treatment facility.

Explanatory drawing of the furnace operation method of the waste processing equipment and waste processing equipment by the present invention (A), (b), (c) is a diagram explaining the Brayton cycle of the turbocharger Explanatory drawing of the waste disposal facility showing another embodiment Explanatory drawing of the waste disposal facility showing another embodiment Explanatory drawing of the waste disposal facility showing another embodiment Explanatory drawing of the waste disposal facility showing another embodiment Explanatory drawing of the waste treatment facility of the prior art Explanatory drawing of the waste treatment facility of the prior art Explanatory drawing of the waste treatment facility of the prior art

  Hereinafter, embodiments of the waste treatment facility and the furnace operation method of the waste treatment facility according to the present invention will be described.

  FIG. 1 shows a waste treatment facility 1 for incinerating waste such as sludge. The waste treatment facility 1 includes a sludge storage tank 20 in which sludge is stored, a sludge charging mechanism 21, a fluidized bed incinerator 2 which is an example of a waste treatment furnace, an exhaust gas treatment facility, and the like.

  The fluidized bed incinerator 2 heats the sludge supplied from the sludge input mechanism 21 to the fluidized bed formed by the high temperature air supplied from the air supply mechanism A, and heats the gasified sludge to the free board section. It is a processing furnace that burns in Reference numeral 14a is a temperature rising burner that heats the inside of the furnace at the time of start-up. After the furnace has been heated, the auxiliary burner indicated by reference numeral 14b is operated to supplement the amount of heat necessary for combustion.

  Along the flue of the fluidized bed incinerator 2, a first heat exchanger 3 that preheats combustion air by the retained heat of the exhaust gas, a dust collector 9 that collects soot, and an alkali agent are sprayed in the exhaust gas. A flue gas treatment tower 10 and the like for neutralizing the acid gas component are sequentially arranged.

  An induction blower 11 that maintains a negative pressure in the furnace is provided on the downstream side of the flue gas treatment tower 10, and exhaust gas attracted by the induction blower 11 is exhausted from the chimney 12.

  The air supply mechanism A described above includes a pusher blower 5, a supercharger 4, and a first heat exchanger 3. Combustion air preliminarily compressed to 1 to 19 kPa by the pusher blower 5 is supplied to the air supply port of the compressor 4b constituting the supercharger 4 through the air passage 8, and the compressor 4b reduces the pressure to 0.1 to 0.3 MPa. The compressed air is preheated by the first heat exchanger 3 and then supplied to the turbine 4a. The compressed air exhausted from the turbine 4a is supplied to the fluidized bed incinerator 2.

  The air compressed by the compressor 4b is heat-exchanged with the exhaust gas at 800 to 1000 ° C. by the first heat exchanger 3 and preheated to 500 to 750 ° C. and then supplied to the turbine 4a.

  When the compressed air preheated by the first heat exchanger 3 is supplied to the turbine 4a, the turbine 4a is rotationally driven, and the compressor 4b connected to the drive shaft is driven. The compressed air of 400 to 650 ° C. and 0.02 to 0.04 MPa discharged from the turbine 4a is supplied to the fluidized bed incinerator 2 as fluidizing air, that is, combustion air, to form a fluidized bed. In addition, the pressure demonstrated in this specification is a gauge pressure.

  Since the combustion air pre-compressed by the pusher blower 5 is supplied to the compressor 4b of the supercharger 4, the air compressed not only by the compressor 4b but also by the pusher blower 5 is preheated by the first heat exchanger 3. Become so. Thereby, the expansion work of the turbine 4a becomes more than the compression work of the compressor 4b, and combustion air can be supplied at a pressure higher than the ventilation pressure loss when forming the fluidized bed in the fluidized bed incinerator 2. It is configured as follows.

  As shown in FIG. 2 (a), the gas turbine and the supercharger are devices that operate according to the Brayton cycle, and a pressure increasing process (1 → 2 in the figure) by adiabatic compression in the compressor, a combustor and a heat exchanger. The heat supply process (2 → 3 in the figure) and the pressure reduction process (3 → 4 in the figure) by adiabatic expansion in the turbine are repeated. Rotation is maintained when the expansion work at the turbine exceeds the compression work at the compressor.

  However, as shown in FIG. 2B, when a configuration is adopted in which the air supply port of the compressor 4b is opened to the atmosphere and the outside air is directly sucked, the expansion work amount x in the turbine 4a is reduced by the air pressure loss to the fluidized bed. Since it is restricted by x1 and ventilation resistance x2, the expansion work x in the turbine 4a becomes smaller than the compression work y in the compressor 4b (x <y), and the supercharger 4 cannot be operated.

Therefore, in the present invention, air is supplied from the pusher blower 5 to the compressor 4b through the blower path 8.
As shown in FIG. 2 (c), the combustion air pre-compressed by the pusher blower 5 is supplied to the air supply port of the compressor 4b, so that the compression work y in the compressor 4b is substantially equal to the pre-compression amount y1. (X> y), the turbocharger 4 can be operated properly even if there is a ventilation pressure loss x1 and ventilation resistance x2 to the fluidized bed.

  Moreover, since the discharge pressure by the pusher blower 5 can be reduced as compared with the case where the supercharger 4 is not used, the power consumption of the pusher blower 5 can be reduced. However, when the fluidized bed incinerator 2 is started up, it is necessary to form the fluidized bed only with the forced blower 5 alone, but the ventilation resistance of the supercharger 4 is small, and the supercharger is raised as the temperature is raised by the start-up. 4 can reduce the power cost.

  At the time of start-up, since the supercharger does not function, it is necessary to increase the air pressure from the pusher fan, but it is limited to the initial temperature rise period at the time of start-up, so it does not increase the operating cost, A complicated operation as disclosed in Patent Document 2 is also unnecessary.

  A description will be given with reference to FIG. 1 again. The waste treatment facility 1 is provided with a control unit 6. The control unit 6 controls the rotational speed of the forced blower 5 on the basis of the oxygen concentration of the exhaust gas detected by the oxygen gas sensor Sg provided at the outlet of the free board unit, so that the fluidized bed incinerator 2 performs appropriate combustion. The supply amount of the combustion air to the fluidized bed incinerator 2 is adjusted so as to be maintained in the state.

  The controller 6 calculates the target air amount to be supplied into the furnace by performing a calculation based on the deviation between the oxygen concentration of the exhaust gas detected by the oxygen gas sensor Sg and the target oxygen concentration. An air amount required for complete combustion is set based on a theoretical air amount assumed in advance, and a reference oxygen concentration remaining in the exhaust gas at that time is calculated. Feedback calculation is performed so that the target air amount is decreased when the oxygen concentration of the exhaust gas detected by the oxygen gas sensor Sg is higher than the reference oxygen concentration, and is increased when the oxygen concentration of the exhaust gas is lower than the reference oxygen concentration. It is.

  Further, the control unit 6 calculates the target rotational speed of the forced air blower 5 based on the deviation between the air amount detected by the flow meter M installed between the forced air blower 5 and the compressor 4b and the target air amount, The inverter 7 is controlled so that the pushing fan 5 has the target rotational speed.

  By using the oxygen concentration contained in the exhaust gas as an indicator, it is possible to grasp the appropriate amount of combustion air for the organic components of the sludge combusted in the fluidized bed incinerator 2, and the target amount is set based on the indicator. Therefore, it becomes possible to supply the combustion air without greatly exceeding the required amount.

  Since the volume of gas changes due to changes in temperature and pressure, it is necessary to make corrections according to temperature and pressure when measuring the flow rate. For this reason, if the temperature or pressure deviates from the assumed range, the error increases. Therefore, it is desirable to install the flow meter M where there is little change in temperature or pressure if possible. In addition, although the change of temperature and pressure is the smallest in the inflow side of the air to a forced air blower, the new piping for installing the flow meter M is needed. Further, since the temperature and / or pressure rises at any of the outlet side of the compressor, the outlet side of the heat exchanger, and the outlet side of the turbine, a flow meter M is provided in the air passage from the pusher fan to the compressor. preferable.

  Moreover, the adjustment method of the supply amount of the combustion air of the pusher blower 5 is not a method of adjusting by receiving resistance of a damper mechanism or the like that causes the power cost to increase, but is a method of controlling the rotational speed of the pusher blower 5. This method can provide a simpler control method in addition to the power cost and the apparatus cost.

  That is, in the above-described waste treatment facility, a compression process in which combustion air pre-compressed by an indenter blower is compressed by a compressor, and combustion air compressed in the compression process is converted into in-core combustion heat of a heat treatment furnace and / or A preheating process that preheats with the retained heat of the exhaust gas that is led to the flue, a compression power generation process that rotates the turbine with the combustion air preheated in the preheating process and transmits the power to the compressor, and an exhaust from the turbine in the compression power generation process And a combustion air supply step of supplying the burned combustion air to the heat treatment furnace.

Hereinafter, another embodiment of the present invention will be described.
As shown in FIG. 3, the high-temperature compressed air discharged from the turbine 4a is arranged by arranging the second heat exchanger 13 in the flue so as to be in series with the first heat exchanger 3 along the flow direction of the exhaust gas. It is preferable to provide an air supply passage 17 that is further preheated by the second heat exchanger 13 and then supplied as combustion air to the fluidized bed incinerator 2.

  By further preheating the high-temperature compressed air discharged from the turbine 4a with the second heat exchanger 13, even if the object to be treated is sludge having a high water content, fossil fuel is supplied to the auxiliary burner 14b and heated. The combustion temperature in the furnace can be maintained in an appropriate state. Thereby, the consumption of fossil fuel can be reduced.

  As shown in FIG. 4, the second heat exchanger 13 may be arranged in the flue so as to be in parallel with the first heat exchanger 3 along the flow direction of the exhaust gas.

  In order to adjust the temperature of the compressed air supplied into the furnace, a bypass pipe 15 that bypasses the second heat exchanger 13 is provided to adjust the mixing amount with the compressed air heated by the second heat exchanger 13. You may comprise.

  A flow rate adjusting valve is provided in each of the air supply pipes to the bypass pipe 15 and the second heat exchanger 13, and the temperature of the combustion air supplied to the fluidized bed incinerator 2 is adjusted by adjusting the opening degree of each valve. The target temperature can be adjusted.

  In the embodiment described above, the example in which the inverter 7 is controlled so that the forced air blower 5 reaches the target rotational speed has been described, but the valve V1 is provided in the ventilation path between the forced air blower 5 and the compressor 4b without using the inverter 7. At the same time, a ventilation rate may be adjusted by providing a valve V2 (see FIG. 5) that can open the ventilation path to the atmosphere.

  As shown in FIG. 5, when the furnace is started up, the valve V1 is opened and air is blown from the pusher blower 5, and after the furnace is raised, the valve V2 is opened to allow the outside air to be sucked and blown by the pusher blower 5. You may comprise so that the supply amount of the required combustion air can be ensured even if it is not.

  Furthermore, when incinerating an object to be processed having a high calorific value in the fluidized bed incinerator 2, a cooling mechanism or a heat extraction mechanism for lowering the furnace temperature may be provided in order to suppress the combustion temperature.

  For example, a cooling device 16a having a two-fluid nozzle may be installed in the fluidized bed portion, or a cooling device 16b having a water spray mechanism may be placed in the free board portion. The controller 6 can adjust the water spray amount from the two-fluid nozzle and the water spray amount from the water spray mechanism, and can adjust the temperature using the latent heat of evaporation.

  In the above-described embodiments, the first heat exchanger 3 is configured to preheat the compressed air by the retained heat of the exhaust gas guided to the flue. However, the first heat exchanger 3 is configured to flue. It is not restricted to the aspect installed in this, For example, it may be comprised in the free board part of the fluidized bed type incinerator 2, and it may be comprised so that compressed air may be preheated with the combustion heat in a furnace.

  FIG. 6 shows a preferred configuration for smoothly starting up the waste treatment facility shown in FIG. A bypass air passage 8b that bypasses the first heat exchanger 3 is provided, and a hot air furnace 14c that heats the combustion air passing through the bypass air passage 8b is provided. Further, a valve V3 is provided in the vicinity of the upstream side of the first heat exchanger 3, and a valve V4 is provided on the upstream side of the hot stove 14c of the bypass air passage 8b.

  When starting up, the valve V3 is closed and the valve V4 is opened, and the combustion air from the forced air blower 5 is heated by the hot stove 14c and supplied to the turbine 4a. The amount of air distribution to the first heat exchanger 3 is increased by gradually increasing the opening of the valve V3 and gradually decreasing the opening of the valve V4 in accordance with the degree of temperature rise in the furnace. The fuel consumption is suppressed by stopping 14c. Since the preheated air temperature can be adjusted by adjusting the amount of ventilation to the bypass air passage 8b, the amount of pressure increase by the supercharger 4 and the combustion temperature of the fluidized bed incinerator can be controlled. It is possible to use the furnace temperature raising burner 14a at the time of start-up, and only one of them may be used. When only one of them is used, it is preferable to use the hot stove 14c from the viewpoint of uniform heating in the furnace.

  When the heat treatment furnace is started up, waste heat of the furnace cannot be used, and pressure loss due to ventilation of the air passage or the heat exchanger occurs. However, by bypassing the first heat exchanger when starting up the heat treatment furnace, the air flow path can be shortened, and by heating the combustion air with the hot air furnace, the heat supply to the turbine and the temperature rise of the heat treatment furnace can be reduced. It becomes possible. In addition, since the preheated air temperature can be adjusted by adjusting the air flow rate to the bypass air passage even after the heat treatment furnace is started up, the amount of pressure increase by the turbocharger and the heat treatment furnace temperature can be adjusted. Become.

  Although embodiment mentioned above demonstrated the case where the fluidized-bed type incinerator 2 was employ | adopted as a heat treatment furnace, the incinerator to which this invention is applied is not restricted to the fluidized-bed type incinerator 2, Similarly, the present invention can be applied to other types of industrial furnaces such as a shaft furnace having a large airflow pressure loss. For example, a coke bed is formed at the bottom, and a heat treatment furnace or scrap that melts by pouring sludge from above the shaft furnace in which the tuyere that supplies combustion air to the coke bed is formed is melted by charging. The present invention can also be applied to a cupola or the like.

  Each of the above-described embodiments is an example of the present invention, and the present invention is not limited by the description. The specific configuration of each part can be appropriately changed and designed within the range where the effects of the present invention are exhibited. Needless to say.

1: Waste treatment facility 2: Fluidized bed incinerator 3: First heat exchanger 4: Supercharger 4a: Turbine 4b: Compressor 5: Pushing fan 6: Control unit 8: Air passage 13: Second heat exchanger

Claims (8)

A waste treatment facility equipped with a heat treatment furnace including a fluidized bed furnace and a shaft furnace for incinerating waste such as sludge,
A first heat exchanger that preheats combustion air using in-furnace combustion heat of the heat treatment furnace and / or retained heat of exhaust gas guided to a flue;
A turbocharger comprising: a turbine rotating by combustion air preheated by the first heat exchanger; and a compressor for supplying combustion air to the first heat exchanger by rotation of the turbine;
A forced blower for precompressing and supplying combustion air to the compressor;
A bypass air passage that bypasses the first heat exchanger;
A hot stove for heating combustion air provided in the bypass air passage and passing through the bypass air passage;
Waste treatment facility equipped with.   The first heat exchanger is configured to preheat combustion air by the retained heat of exhaust gas guided to the flue, and a second heat exchanger is provided in the flue in parallel or in series with the first heat exchanger. The waste treatment facility according to claim 1, wherein an air supply passage is provided for supplying the combustion air discharged from the turbine to the heat treatment furnace after further preheating with the second heat exchanger.   The waste treatment facility according to claim 1 or 2, further comprising a control unit that controls the number of revolutions of the forced air blower so that a supply amount of combustion air to the heat treatment furnace becomes a target amount.   The waste treatment facility according to claim 3, wherein the control unit is configured to set the target amount based on at least an oxygen concentration contained in an exhaust gas of the heat treatment furnace. The waste treatment facility according to any one of claims 1 to 4 , further comprising an induction blower for extracting exhaust gas from the heat treatment furnace. A method of operating a waste treatment facility comprising a heat treatment furnace including a fluidized bed furnace and a shaft furnace for incinerating waste such as sludge,
A compression step of compressing the combustion air pre-compressed by the forced blower with a compressor;
A preheating step in which the combustion air compressed in the compression step is preheated by the in-furnace combustion heat of the heat treatment furnace and / or the retained heat of the exhaust gas guided to the flue;
A compression power generation step of rotating the turbine with combustion air preheated in the preheating step and transmitting power to the compressor;
A combustion air supply step of supplying the combustion air exhausted from the turbine in the compression power generation step to the heat treatment furnace;
At least at the time of starting the heat treatment furnace, the combustion air compressed in the compression step is led to a bypass air passage bypassing the preheating step, and preheated in a hot air furnace provided in the bypass air passage;
Of waste treatment facilities including A second preheating step of preheating the combustion air exhausted from the turbine in the compression power generation step again by the in-furnace combustion heat of the heat treatment furnace and / or the retained heat of the exhaust gas guided to the flue;
The furnace operation method for a waste treatment facility according to claim 6 , wherein the combustion air preheated again in the second preheating step is supplied to the combustion air supply step. The operation of the waste treatment facility according to claim 6 or 7 , further comprising a pusher blower control step of controlling a rotation speed of the pusher blower so that the combustion air pre-compressed by the pusher blower has a target air amount. Furnace method.

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