JP6804183B2 - Fluidized bed sludge incinerator - Google Patents

Description

The present invention relates to a fluidized bed sludge incinerator for burning sludge.

Global warming nitrous oxide known as a gas (hereinafter N _{2 O)} is by far the reasons such as was not a gas regulated emissions concentration measurement and an exhaust gas N ₂ O in the sewage sludge combustion furnace Combustion control by concentration has not been performed. However, it has been known that N ₂ O produces a warming effect about 300 times that of CO ₂ , and since sewage sludge is rich in nitrogen components, its combustion exhaust gas is as high as several hundred ppm. Since it contains ₂ O, it is desired to reduce the amount of N ₂ O discharged from the sewage sludge combustion furnace as much as possible.

According to Patent Document 1, in order to reduce the N ₂ O concentration of the exhaust gas, the sludge incinerator is divided into three zones in the height direction, and N ₂ O is efficiently decomposed in the high temperature combustion zone directly above the sand layer. and a technique for reducing the N _{2 O} in the exhaust gas of the combustion furnace is described.

Japanese Patent No. 4413275

Meanwhile, the air ratio of the combustion air to reduce the N _{2 O} emissions while maintaining combustion efficiency is fed to the sand layer (fluidized bed) (primary air ratio) is low is better as possible. For example, even in the apparatus described in Patent Document 1 described above, the primary air ratio is appropriately set to 0.9 to 1.1.
However, if the primary air ratio is reduced to 0.9 or less, the amount of combustion in the sand layer decreases and the sand layer temperature cannot be maintained at a predetermined value, causing poor flow of the sand layer and reducing combustion efficiency. There was a problem and it could not be lowered below this. Therefore sludge treatment amount and sludge when less combustion heat and the like of itself, was also the case where the high-temperature holding for N 2 _O emissions reduction should become realized in co fuel flow rate increases.

The present invention aims to provide a fluidized bed sludge incinerator can be reduced N _{2 O} emissions combustion gas discharged from the incinerator main body.

According to the first aspect of the present invention, the fluidized bed type incinerator is a combustion air supply device that supplies combustion air to an incinerator main body to which sludge is supplied and a sand layer provided below the incinerator main body. When the N _{2 O} concentration sensor for measuring the concentration of N _{2 O} combustion gas discharged from the incinerator main body, and a control unit for adjusting the quantity of combustion air based on the detected value of the N _{2 O} concentration sensor, have the sand is circular in plan view, said combustion air supply device is disposed on a first side portion of the circular portion which is bisected by a straight line which does not pass through the center of the circular a first diffusion pipe group that includes a second aeration tube group arranged in a portion of the opposite second side and the first is a part smaller than the area of the side and the first side portion In the adjustment, the control device may control the combustion air supply device to supply the combustion air to the first air diffuser group and the second air diffuser group to flow all of the sand layer. At the same time, when the amount of combustion air is reduced, the combustion air is supplied only to the first incinerator group to limit the flow range of the sand layer to the first side.

According to this configuration, in the case of performing control to reduce the quantity of combustion air based on the N 2 _O concentration, reducing the quantity of combustion air while maintaining a superficial velocity by limiting the flow range of sand becomes possible, it is possible to reduce the N _{2 O} emission of the combustion gas discharged from the incinerator main body.

In the fluidized bed type sludge incinerator, the free board section temperature sensor for measuring the temperature of the free board section of the incinerator body and the sand layer temperature sensor for measuring the temperature of the sand layer are provided, and the control device is said to be free. The flow range may be changed based on at least one of the temperature of the board portion and the temperature of the sand layer.

According to such a configuration, it is possible that the temperature of the freeboard section and sand to prevent an increase in N _{2 O} concentration by be lowered.

According to the present invention, the temperature of the sand layer can be maintained above a predetermined value by limiting the flow range of the sand layer even when the control for reducing the amount of combustion air is performed based on the N ₂ O concentration. That is, it is possible to reduce the quantity of combustion air while maintaining a superficial velocity, which makes it possible to reduce the N _{2 O} concentration of the combustion gas discharged from the incinerator main body.

It is a schematic block diagram of the fluidized bed type sludge incinerator of the 1st Embodiment of this invention. It is a schematic block diagram of the air diffuser of the fluidized bed type sludge incinerator of the 1st Embodiment of this invention. It is a logic diagram of the combustion air amount adjustment in the control of the fluidized bed type sludge incinerator of the 1st Embodiment of this invention. It is a logic diagram of the secondary air flow rate adjustment in the control of the fluidized bed type sludge incinerator of the 1st Embodiment of this invention. It is a logic diagram of the combustion air temperature control in the control of the fluidized bed type sludge incinerator of the 1st Embodiment of this invention. It is a logic diagram of the auxiliary fuel flow rate adjustment in the control of the fluidized bed type sludge incinerator of the 1st Embodiment of this invention. It is a figure explaining the situation which limited the flow range in the air diffuser of the fluidized bed type sludge incinerator of the 1st Embodiment of this invention. It is a graph which shows the relationship between the amount of combustion air and the superficial velocity. It is a schematic block diagram of the air diffuser of the fluidized bed type sludge incinerator of the modification of 1st Embodiment of this invention. It is a schematic block diagram of the air diffuser of the fluidized bed type sludge incinerator of the modification of 1st Embodiment of this invention. It is a schematic block diagram of the air diffuser of the fluidized bed type sludge incinerator of the 2nd Embodiment of this invention.

(First Embodiment)
Hereinafter, the fluidized bed sludge incinerator of the first embodiment of the present invention and the incineration method using the fluidized bed sludge incinerator will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of the fluidized bed sludge incinerator 100 of the present embodiment. The fluidized bed type sludge incinerator 100 is a combustion furnace in which sand grains are used as a heat medium to form a bubble fluidized bed together with sludge and burn.

As shown in FIG. 1, the fluidized bed type sludge incinerator 100 burns in the incinerator main body 1 to which the sludge cake 14 which is sludge is supplied and the sand layer S (fluidized bed) provided in the lower part of the incinerator main body 1. It has an incinerator 30 which is a combustion air supply device for blowing air (primary air), and a control device 2. Above the sand layer S of the incinerator main body 1, the freeboard portion F is formed.
The sludge cake 14 (sludge) is put into the sand layer S inside the incinerator main body 1 from the feeder 15. The feeder 15 is provided with a sludge moisture content sensor 18 for measuring the moisture content (input water content) of the sludge cake 14.

The incinerator main body 1 has an auxiliary fuel supply device 10 that supplies auxiliary fuel to the sand layer S, and a secondary air supply device 9 that supplies secondary air to the freeboard portion F. The auxiliary fuel supply device 10 includes a flow rate sensor 42 for measuring the auxiliary fuel flow rate and an auxiliary fuel control valve 40 for adjusting the auxiliary fuel flow rate.
The combustion gas (exhaust gas after combustion) discharged from the incinerator main body 1 is introduced into an exhaust gas treatment device such as a gas cooling tower or a bag filter from the upper part of the furnace via the flue 16.

As shown in FIGS. 1 and 2, the air diffuser 30 includes an air supply device 32 such as a blower, an air preheater 33 (heater), a header pipe 34, and a plurality of air diffusers 31. ing.
The air preheater 33 is installed between each air diffuser 31 and the air supply device 32. The air preheater 33 may be omitted. The air from the air supply device 32 is supplied to the header pipe 34. The header pipe 34 is connected to each of the plurality of air diffuser pipes 31. Each air diffuser 31 is formed in a straight pipe shape, and is supported by the incinerator body 1 in a state of being inserted into the incinerator body 1 so that the axis of the air diffuser 31 is horizontal.

The air supply device 32 supplies air to the header pipe 34. The air preheater 33 preheats this air. The air preheater 33 recovers heat from the exhaust gas discharged from the incinerator main body 1, for example, to preheat the air.

The header pipe 34 and the air diffuser pipe 31 are connected by a combustion air line 35. Of the plurality of air diffusers 31, the combustion air line 35 includes, for example, a first combustion air line 35a that supplies combustion air to 70% of the first air diffuser group 31a, and another 30% of the second air diffuser group 31b. It is composed of a second combustion air line 35b that supplies combustion air to the air. A stop valve 36 is provided in the second combustion air line 35b. The stop valve may be provided in the first combustion air line 35a.

Specifically, the plurality of air diffusers 31 are arranged so as to be parallel to each other in the vicinity of the bottom of the sand layer S. The first air diffuser group 31a is arranged on the first side (left side in FIG. 2) when viewed from above, and the second air diffuser group 31b is on the second side (right side in FIG. 2) opposite to the first side. ) Is placed.

The preheated air is blown from the header pipe 34 through the air diffuser pipe 31 into the sand layer S. The sand layer S contains fluidized sand as a fluidized medium.
The air diffuser 30 has a mechanism capable of supplying combustion air only to the first air diffuser group 31a, which is a part of the air diffuser 31, among the plurality of air diffuser 31.

The fluidized bed type sludge incinerator 100 includes a sand layer temperature sensor 8 that detects the temperature Ts in the sand layer region, a free board unit temperature sensor 7 that detects the temperature Tf of the free board unit F, and oxygen that detects the exhaust gas oxygen concentration of the flue 16. The density sensor 6 is provided. Further when passing the combustion gases into freeboard top, and a N _{2 O} concentration sensor 17 for detecting the N _{2 O} concentration of the combustion gas.

Next, the process of sludge combustion will be described.
The sewage sludge is dehydrated by a dehydration process (not shown), and is supplied to the incinerator main body 1 by the feeder 15 as sludge cake 14. Auxiliary fuel is preheated to the combustion furnace sand layer area via the auxiliary fuel control valve 40, and combustion air is preheated by the temperature controller 12 via the combustion air flow rate control valve 11 by the discharge pressure of the air supply device 32. It is heated by the vessel 33, introduced from the bottom of the combustion furnace, and burned.
The sand grains of the heated sand layer S flow together with the supplied sludge cake 14 by the combustion air and the generated combustion gas, and the sludge cake 14 burns while flowing. Further, the sludge cake combustion gas rises in the freeboard portion F, and the combustion is completed by the secondary air supplied through the secondary air control valve 41. The exhaust gas after combustion is discharged from the upper part of the furnace through the flue 16 to the exhaust gas treatment facility.

The N ₂ O concentration sensor 17 receives the laser light absorbed by the laser light emitting unit 5 that irradiates the laser light of a specific wavelength from one end of the combustion gas passing portion above the free board portion F and the N ₂ O of the combustion gas passing portion. It is composed of a laser light receiving unit 4 that detects the intensity of the laser and a laser densitometer 3 that calculates the density from the detection signal and outputs the signal to the control device 2. N ₂ O absorbs a wavelength of 1.517 μm, attenuates the irradiation light, reaches the laser receiving unit 4, and is detected.
The control device 2 accepts these control amounts, combustion condition process values, and the like, and outputs an operation signal necessary for adjusting the amount of air required for combustion, the flow rate of auxiliary fuel, the air temperature, and the like.

In then present embodiment, a description will be given of a control method of the combustion furnace to reduce the N 2 _O emissions.
The control device 2 is provided with a correction value calculation unit based on a calculation by fuzzy inference, and each detection value (N ₂ O,) detected in the above description is provided in the correction value calculation unit according to the eight-level fuzzy inference rule shown in Table 1. O _2, Ts, enter the grade value of the fuzzy set of Tf) as antecedent part, and outputs combustion air, secondary air, the correction value α of the amount and the combustion air temperature co fuel from subsequent matter portion.

Further, the control device 2 has an operation signal generation unit, generates an adjustment operation amount based on the correction value α, and outputs an operation signal of each adjustment valve or controller. The logic diagram is shown in FIGS. 3 to 6 for each amount of combustion air, secondary air, auxiliary fuel, and combustion air temperature, respectively.

Explaining with an example of combustion air flow rate adjustment with reference to FIG. 3, the fuzzy calculation correction value α is a signal obtained by inputting a sludge cake amount setting value (SV, set value) to the function generator 20 and converting it into a combustion air flow rate setting value. It is added by the adder 21 to obtain a corrected combustion air flow rate set value. The corrected combustion air flow rate set value and the combustion air flow rate process value (PV, process value) are input to the PID circuit 22, the operation signal of the combustion air flow rate control valve is output by the PID operation, and the combustion air flow rate control valve 11 is opened. Adjust the degree. Hereinafter, the same applies to the amounts of secondary air and auxiliary fuel and the combustion air temperature in FIGS. 4 to 6.

FIG. 4 is a logic diagram of secondary air flow rate adjustment in the control of the sludge combustion furnace of the present invention. In FIG. 4, the fuzzy calculation correction value α is corrected by being added by the adder 21 to the signal obtained by inputting the sludge cake amount setting value (SV, set value) into the function generator 20 and converting it into the secondary air flow rate setting value. Obtain the secondary air flow rate set value. The corrected secondary air flow rate set value and the secondary air flow rate process value (PV, process value) are input to the PID circuit 22, and the opening degree of the secondary air control valve 41 is adjusted by the PID operation.

FIG. 5 is a logic diagram of combustion air temperature control in the control of the sludge combustion furnace of the present invention. In FIG. 5, the fuzzy calculation correction value α is added by the adder 21 to the signal obtained by inputting the sludge cake amount setting value (SV, set value) to the function generator 20 and converting it into the combustion air temperature setting value, and the correction combustion. Obtain the air temperature set value. The corrected combustion air temperature set value and the combustion air temperature process value (PV, process value) are input to the PID circuit 22, the operation signal of the temperature controller 12 is output by the PID operation, and the combustion air temperature is measured by the air preheater 33. Adjust.

FIG. 6 is a logic diagram of auxiliary fuel flow rate adjustment in the control of the sludge combustion furnace of the present invention. In FIG. 6, the fuzzy calculation correction value α is added by the adder 21 to the signal obtained by inputting the sludge cake amount setting value (SV, set value) into the function generator 20 and converting it into the auxiliary fuel flow rate set value, and the correction assistance is performed. Obtain the fuel flow rate set value. The corrected auxiliary fuel flow rate set value and the auxiliary fuel flow rate process value (PV, process value) are input to the PID circuit 22, and the opening degree of the auxiliary fuel control valve 40 is adjusted by the PID operation.

Here, in order to reduce the N _{2 O} emissions while maintaining combustion efficiency, use many times the air in the primary air ratio (minimum required amount of air upon incineration of sludge (theoretical air quantity) The ratio) should be as low as possible. According to the existing technology, the primary air ratio of 0.9 to 1.1 is appropriate.
In performing the control as described above, if the control is performed so as to further reduce the primary air ratio (when the control is performed to reduce the amount of combustion air below a predetermined amount), the amount of combustion air is reduced. The superficial velocity cannot be maintained in the sand layer S. That is, the amount of combustion in the sand layer S is reduced, and the combustion efficiency is reduced due to poor flow, so that the sand layer temperature cannot be maintained at a predetermined value.

When the control device 2 of the present embodiment controls to reduce the amount of combustion air, the air diffuser 30 is controlled to control the flow range of the sand layer S, that is, the range in which the flow sand, which is a flow medium, flows in the sand layer S. It has a flow range limiting unit that limits the flow range. That is, the control device 2 can control the sand layer S to be divided into a fluidized portion and a non-fluidized portion.
The flow range limiting unit limits the flow range of the sand layer S by providing the sand layer S with a region having a combustion air supply amount that is lower than the fluidization start speed of the sand layer S of the present embodiment. Further, the flow range limiting unit relaxes the limitation of the flow range of the sand layer S and causes the entire sand layer S to flow. That is, the flow range limiting unit can change the flow range of the sand layer S.

The flow range limiting unit of the control device 2 of the present embodiment limits the number of air diffusers 31 to which combustion air is supplied in the plurality of air diffusers 31 of the air diffuser 30 in order to limit the flow range.
Specifically, the flow range is gradually limited by controlling each stop valve 36 provided in the second combustion air line 35b to be closed. As a result, as shown in FIG. 7, the flow range R of the sand layer S is limited. That is, the entire sand layer S does not flow, and only a part of the sand layer S flows. In the present embodiment, the flow range R can be limited so that only 70% of the area of the sand layer S in the plan view is flown. The flow range R can be set arbitrarily, but it is preferably 50% or more with respect to the sand layer area. Further, 70% or more is preferable.

Next, the operation and effect of the fluidized bed type sludge incinerator 100 of the present embodiment will be described.
FIG. 8 is a graph showing the relationship between the amount of combustion air and the superficial velocity. As shown in FIG. 8, both when the flow area is 100% (100% of the sand layer S is the flow range) and when the flow area is 70%, the superficial velocity increases as the amount of combustion air increases.

If, in the fluidized bed sludge incinerator 100 of the present embodiment, the lower limit LL of the superficial velocity is 0.55 m / s and the upper limit HL of the superficial velocity is 0.96 m / s, the amount of combustion air is When it becomes the predetermined value X or less, the superficial velocity of the combustion air falls below the lower limit LL. In such a case, the control device 2 sets the flow area to 70%, that is, limits the flow range. As a result, the cavity velocity recovers to about 0.80 m / s. That is, even when the amount of combustion air is lowered to a predetermined value X or less, the superficial velocity of the sand layer S can be maintained within the upper and lower limits of the superficial velocity.

Further, the control device 2 adjusts the amount of combustion air based on the temperature Tf of the freeboard unit F (detected value of the freeboard unit temperature sensor 7).
Here, N 2 _O concentration is the temperature of the freeboard section F is decomposed higher is accelerated known (fluidized layer Handbook (Co. Baifukan, published 1999) refer). As a means for raising the temperature of the freeboard portion F, there is a means for increasing the auxiliary fuel flow rate or reducing the amount of combustion air (approaching the air ratio to 1.0).
Since the superficial velocity is reduced by reducing the fuel air amount, the control device 2 limits the flow range R of the sand layer S based on the fuel air amount.

Further, the control device 2 controls to relax the limitation of the flow range based on the water content of the sludge cake 14 measured by the sludge water content sensor 18. Specifically, when the water content of the sludge cake 14 increases, the amount of combustion air can be small, so that the flow area is usually controlled to be small. However, at this time, if the sand layer temperature drops below a predetermined value, the combustion efficiency drops extremely. In this case, control to increase the auxiliary fuel flow rate, increase the combustion air, increase the amount of combustion air, and increase the flow area. I do. That is, the control device 2 changes the flow range R based on the water content of the sludge cake 14.

Further, the control device 2 performs control to relax the limitation of the flow range based on the oxygen concentration of the combustion gas measured by the oxygen concentration sensor 6. Specifically, when the oxygen concentration of the combustion gas becomes equal to or less than a predetermined value, the fuel air amount is increased and the flow area is controlled to be increased.
When the oxygen concentration of the combustion gas becomes low, it is necessary to increase either the amount of combustion air or the amount of secondary air. When increasing the amount of combustion air, it is necessary to increase the flow area, that is, to widen the flow range because there is an upper limit of the superficial velocity.

Here, the temperature Tf of the freeboard portion F and the temperature Ts of the sand layer S may become lower than a predetermined threshold value during the operation in which the flow range R is limited. In this case, it is necessary to relax the limitation of the flow range R.
On the other hand, the control device 2 performs control to relax the limitation of the flow range based on the temperatures of the freeboard unit F and the sand layer S measured by the freeboard unit temperature sensor 7 and the sand layer temperature sensor 8. Specifically, when the temperature of the freeboard portion F and / or the sand layer S becomes equal to or lower than a predetermined value, the flow area is controlled to be increased.
Further, the control device 2 controls to reduce the flow area when the temperature of at least one of the freeboard portion F and the sand layer S becomes a predetermined value or more. That is, the control device 2 controls to change the flow range R based on at least one of the temperature Tf of the freeboard portion F and the temperature Ts of the sand layer S.

Further, the flow range limiting unit of the control device 2 changes the flow range based on the auxiliary fuel flow rate measured by the flow rate sensor 42.
For example, in order to suppress a decrease in combustion efficiency when the temperature of the sand layer S drops below a predetermined value, control is performed to increase the flow range when the auxiliary fuel flow rate is increased.

According to the above embodiment, when performing control to reduce the quantity of combustion air based on the N 2 _O concentration, reducing the quantity of combustion air while maintaining a superficial velocity by limiting the flow range of sand S Is possible.
Thus, by operating the furnace further reduces the quantity of combustion air, it is possible to furnace temperature maintained without excessively increasing it auxiliary fuel, it is possible to reduce the N _{2 O} emission of the combustion gas.

Further, even when the control for reducing the amount of combustion air is performed based on the temperature Tf of the freeboard portion F, it is possible to reduce the amount of combustion air while maintaining the superficial velocity by limiting the flow range of the sand layer S. It becomes.

Further, it is possible to N _{2 O} reduction by low air ratio operation, can be made compact furnace due to reduction of use amount of air. As a result, by reducing the amount of air, it is possible to reduce the blower power and the auxiliary fuel flow rate.
On the other hand, according to the above embodiment, even in low load operation, it is possible to operate at the same air ratio as in normal operation, and deterioration of fuel efficiency due to an increase in air ratio can be suppressed, and as the amount of combustion air decreases. Blower power can also be reduced.

Further, when the water content of the sludge cake 14 increases and the temperature of the sand layer S becomes equal to or less than a predetermined value, the limitation of the flow range is relaxed, so that the temperature of the sand layer S can be prevented from decreasing.

Further, when the oxygen concentration of the combustion gas becomes a predetermined value or less, incomplete combustion due to a decrease in the oxygen concentration can be prevented by relaxing the limitation of the flow range.

Further, by changing the flow range R based temperature Ts of the temperature Tf and sand S in the freeboard section F or in either, it is possible to prevent an increase in N 2 _O concentration.

In the above embodiment, the stop valve 36 of the second combustion air line 35b is closed to stop the combustion air supplied to the second air diffuser group 31b, but the present invention is not limited to this. Absent. For example, a regulating valve may be provided as an alternative to the stop valve 36 to reduce the amount of combustion air supplied to the second air diffuser group 31b.

Further, the arrangement of the plurality of air diffusers 31 constituting the air diffuser 30 is not limited to the arrangement shown in FIG. For example, as shown in FIG. 9, the first air diffuser group 31a among the plurality of air diffuser 31 may be arranged between the second air diffuser group 31b. That is, the first air diffuser group 31a is arranged in the central portion in a predetermined direction along the horizontal direction, and the second air diffuser group 31b is arranged on both sides of the first air diffuser group 31a.

The position of the flow range R can be changed by changing the plurality of air diffusers 31. By arranging as shown in FIG. 9, when the flow range R is limited, only the sand layer S near the center when viewed from the side can be flowed.

Further, as shown in FIG. 10, the air supply device 32a that supplies air to the first air diffuser group 31a and the air supply device 32b that supplies air to the second air diffuser group 31b are used as separate air supply devices 32. May be good.
With such a configuration, backflow of air can be prevented.

(Second Embodiment)
Hereinafter, the fluidized bed sludge incinerator of the second embodiment of the present invention will be described with reference to the drawings. In this embodiment, the differences from the first embodiment described above will be mainly described, and the description thereof will be omitted for the same parts.
As shown in FIG. 11, the air diffuser 30B (combustion air supply device) of the fluidized bed type sludge incinerator of the present embodiment is provided with a dispersion plate 43 in which the sand layer S is filled above and below the dispersion plate 43. It has a wind box 44 and a wind box 44. The air box 44 is an introduction portion for combustion air, and the sand layer S and the air box 44 are separated by a dispersion plate 43.

A plurality of air supply holes 45 are formed in the dispersion plate 43. Although not shown, the air supply hole 45 is formed in the entire surface of the dispersion plate 43. A combustion air nozzle 46 is attached to the upper portion of the air supply hole 45. The combustion air nozzle 46 has a plurality of (only one is shown in FIG. 11) outlets 47 that are open outward in the horizontal direction. The ejection port 47 is formed so as to eject combustion air slightly below the horizontal direction.

Further, the wind box 44 is partitioned by a partition wall 48. The partition wall 48 divides the wind box 44 into a first wind box 44a and a second wind box 44b. The area of the first wind box 44a can be, for example, 70% of the total area of the wind box 44. Further, in this embodiment, the number of partition walls is one, but the number of partition walls is not limited to one.

The air diffuser 30B of the fluidized bed type sludge incinerator of the present embodiment can supply combustion air to only one of the plurality of air boxes 44a and 44b. That is, the flow range limiting unit of the control device 2 of the present embodiment is provided in the second combustion air line 35b in the plurality of air boxes 44a and 44 of the air diffuser 30B in order to limit the flow range. The flow range is limited by controlling the shutoff valve 36 to be closed.
The position of the partition wall 48 is not fixed but can be adjusted. That is, by moving the position of the partition wall 48, the flow area when limiting the flow range can be changed.

The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

1 Incinerator body 2 Control device 3 Laser densitometer 4 Laser light receiving part 5 Laser light emitting part 6 Oxygen concentration sensor 7 Free board part temperature sensor 8 Sand layer temperature sensor 9 Secondary air supply device 10 Auxiliary fuel supply device 11 Combustion air flow rate Control valve 12 Temperature controller 14 Sludge cake 15 Feeder 16 Smoke path 17 N ₂ O Concentration sensor 18 Sludge moisture content sensor 20 Function generator 21 Adder 22 PID circuit 30, 30B Air diffuser (combustion air supply device)
31 Air diffuser 32 Air supply device 33 Air preheater 34 Header pipe 35 Combustion air line 36 Stop valve 40 Auxiliary fuel control valve 41 Secondary air control valve 42 Flow sensor 43 Dispersion plate 44 Air box 45 Air supply hole 46 Combustion air nozzle 47 Nozzle 48 Partition 100 Flow bed type sludge incinerator F Free board part P Pump S Sand layer

Claims (2)

The incinerator body to which sludge is supplied and
A combustion air supply device that supplies combustion air to the sand layer provided at the bottom of the incinerator body, and
And N _{2 O} concentration sensor for measuring the concentration of N _{2 O} combustion gas discharged from the incinerator main body,
It has a control device that adjusts the amount of combustion air based on the detected value of the N ₂ O concentration sensor.
The sand layer is circular in plan view and
Said combustion air supply device, first the first aeration tube group arranged in a portion of the side of the portion of said first side of said circular portion which is bisected by a straight line which does not pass through the center of the circular the smaller the area and the first side portion and a second aeration tube group arranged in a portion of the opposite second side,
In the adjustment, the control device can control the combustion air supply device to supply the combustion air to the first air diffuser group and the second air diffuser group to flow all of the sand layer. At the same time, when the amount of combustion air is reduced, the combustion air is supplied only to the first air diffuser group to incinerate the fluidized bed type sludge having a flow range limiting portion that limits the flow range of the sand layer to the first side. Furnace. A freeboard temperature sensor that measures the temperature of the freeboard of the incinerator body,
It has a sand layer temperature sensor that measures the temperature of the sand layer.
The fluidized bed type sludge incinerator according to claim 1 , wherein the control device changes the fluidized range based on at least one of the temperature of the freeboard portion and the temperature of the sand layer.

Images