JP3174210B2 - Waste incinerator and waste incineration method using waste incinerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste incinerator installed in a municipal garbage incineration plant and the like, and a method for incinerating waste using the same.

[0002]

2. Description of the Related Art In general, an incinerator is one of the important devices in a municipal garbage incineration plant, and plays a role of completely burning and incinerating the garbage input and suppressing the generation of harmful substances during the combustion. Play.

[0003] This incinerator is roughly classified into a stoker type and a fluidized bed type. FIG. 9 shows an example of the structure of the fluidized bed incinerator.

[0004] A main body 80 of an incinerator shown in the figure is formed by laminating a refractory material 81, a heat insulating material 82 and a steel shell 83 in this order from the inside, and a sand layer 84 is provided at the bottom. Fluidized air (primary air for combustion) is blown out from below the sand layer 84 through an air diffuser 86 into the sand layer 84, and the sand layer 84 starts flowing by this air. During start-up, the sand layer 84 is heated by the heating burner 87 at the upper part,
When the temperature reaches 700 ° C., dust is introduced into the furnace from the dust feeder 88, and a part of the dust is ignited by the heat of the sand layer and gasified. Part of the heat generated by this combustion is
And the sand layer temperature is kept constant at about 700 ° C.
The gasified garbage is in the space above the sand layer 84 (free board)
90, where secondary combustion is performed while being mixed with the secondary air (auxiliary combustion air) from the secondary combustion air nozzle 89.
It is discharged outside at an outlet temperature of 900 ° C. The non-burnable refuse circulates in the sand layer 84, and finally the non-combustible material discharge pipe
2. The sand (fluid medium) discharged to the outside through the incombustible extractor 94 and the vibrating sieve 96 and separated from the non-burning refuse by the vibrating sieve 96 passes through the fluid medium circulating device 98 to the sand layer 84 in the incinerator. Will be returned.

In the drawing, reference numeral 99 denotes a fuel supply port for supplying auxiliary fuel.

[0006]

In recent years, the emission of dioxins from municipal waste incineration plants has become a major social problem. In order to control such dioxin emission, three Ts, namely, the residence time (Time) of the gas in the free board 90, the temperature (Temperature) in the free board 90, and the turbulence of the gas in the free board 90 are described. (Turbulence), that is, the mixing efficiency of gasified refuse and air is considered important.

Here, in the conventional incinerator, the time and the temperature among the above three T sufficiently satisfy the conditions, and the improvement of the mixing is a major problem. As means for improving the mixing of air and unburned gas generated from this waste, (A)
Secondary air is blown into the incinerator from the side to bend the mainstream,
(B) Means have been taken to induce turbulence in the gas by giving the constriction or bend to the shape of the incinerator itself, but none of them has achieved a sufficient effect.

[0008] Instead of improving the degree of mixing, dioxin can be reduced by performing combustion control so as to supply an optimal amount of air to the actual amount of dust. Is difficult to accurately measure, and the combustion state changes depending on the quality of the dust, so that it is practically difficult to execute such accurate combustion control.

In view of such circumstances, the present invention provides a waste incinerator capable of reducing dioxin emissions by effectively mixing waste such as gasified garbage and auxiliary combustion air. The purpose is to provide.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a waste incinerator in which waste supplied to the inside is burned, gasified and discharged to the outside. Primary combustion zone for pyrolysis and gasification of
A secondary combustion region located above the next combustion region and further burning the gas generated in the same region,
At the outlet of the secondary combustion area, auxiliary combustion air is directed downward.
The injection forms a recirculation vortex of the gas flowing upward from the inlet portion and downward before the outlet portion in the secondary combustion region (claim 1).

Further, according to the present invention, as means for forming the recirculation vortex, air supply means for supplying auxiliary combustion air to the inside of the waste incinerator is provided. The internal shape of the incinerator in the secondary combustion zone and the location and direction of the auxiliary combustion air supplied by the air supply means so as to form a recirculation vortex of the gas turning upward and turning downward just before the outlet portion. And the air supply means is provided with the secondary combustion
Injecting auxiliary combustion air downward at the exit of the area
It is (claim 2).

More specifically, the internal shape of the incinerator in the secondary combustion zone is set to a shape in which the diameter of the incinerator in the outlet portion of the secondary combustion zone decreases as it goes upward.
It is highly preferable to set a supply point of the auxiliary combustion air by the air supply means at an inlet portion and an outlet portion of the secondary combustion region, and to set the supply direction of the auxiliary combustion air supplied at the outlet portion downward. Claim 3).

Furthermore, the direction of the auxiliary combustion air supplied at the inlet of the secondary combustion region is set so as to swirl (claim 4), and the internal shape of the inlet of the secondary combustion region is raised. It is more preferable to set the shape so as to increase in diameter toward (Claim 5).

It is more preferable to form a tertiary combustion zone between the secondary combustion zone and the outlet of the incinerator where gas burned in the secondary combustion zone stays.

[0015] Further, it is preferable that a cooling jacket is formed in the incinerator side wall surrounding the secondary combustion region and the tertiary combustion region, and a circulation means for flowing a cooling fluid through the cooling jacket is further provided. Preferred (claim 6
8).

In this case, a temperature detecting means for detecting the temperature in the furnace, and a flow rate of the cooling fluid circulated through the cooling jacket by the circulating means based on the temperature detected by the temperature detecting means. Providing the flow control means makes it more effective (claim 9).

In each of the above-mentioned incinerators, by mixing steam or atomized water into the auxiliary combustion air, more excellent effects as described later can be obtained (claim 10).

[0018]

In the incineration method and the waste incinerator according to the first and second aspects, gas is generated by burning waste in the primary combustion zone, and this gas is introduced into the secondary combustion zone to further burn. In the secondary combustion zone, a recirculation vortex of the gas turning upward from the inlet portion and turning downward just before the outlet portion is formed. It can be sufficiently mixed with air.

More specifically, in the waste incinerator according to the third aspect, the auxiliary combustion air supplied to the inlet portion of the secondary combustion region and the unburned fuel generated by burning the waste in the primary combustion region. Gas is introduced into the secondary combustion zone and rises,
It turns at the throttle at the exit of the next combustion zone. Then, the auxiliary combustion air is supplied downward at the outlet portion of the secondary combustion region, whereby the diverted gas is pushed back downward, thereby forming a recirculation vortex.

Further, in the waste incinerator according to the fourth aspect, the auxiliary combustion air is supplied while being swirled at the entrance portion of the secondary combustion region, thereby promoting the formation of the recirculation vortex. In the waste incinerator according to the fifth aspect, the rising gas flows into the secondary combustion region while expanding in the radial direction due to the rapid expansion effect of the gas passage at the entrance portion of the secondary combustion region. By supplying auxiliary combustion air downward at the outlet portion, the formation of a more stable recirculation vortex is promoted.

Here, even if the mixing in the secondary combustion zone is performed well, if charcoal or soot is generated in the combustion gas, or if the amount of oxygen and the amount of fuel supplied are small, the combustion gas is removed from the furnace. Although complete combustion cannot be expected unless the gas is allowed to stay in the inside for a sufficient time, in the waste incinerator according to claim 7, the gas burned in the secondary combustion region stays in the tertiary combustion region on the way to the incinerator outlet. Therefore, more complete combustion is performed.

In the waste incinerator according to the sixth and eighth aspects, a cooling fluid is circulated in a cooling jacket formed in the side wall of the incinerator surrounding the secondary combustion region and the tertiary combustion region. Therefore, the furnace temperature is prevented from rising abnormally, and the heat generated in the furnace can be recovered through the cooling fluid, so that the thermal energy can be effectively used.

Here, in the waste incinerator according to the ninth aspect, since the flow rate of the cooling fluid is controlled based on the actual furnace temperature, the furnace temperature is maintained at a more accurate temperature.

In each of the above incinerators, if the incineration method according to the tenth aspect is carried out, the auxiliary combustion air is mixed with steam having a higher specific gravity or atomized water. The kinetic energy of the water-containing auxiliary air increases. Accordingly, the force of the auxiliary combustion air penetrating the ascending gas against the flow thereof and reaching the center of the waste incinerator (hereinafter referred to as penetration force) increases, thereby forming a stronger recirculation vortex and The vortex intensity can be adjusted.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. In the waste incinerator shown here, the layer structure of the side wall of the incinerator main body 10 and the configuration of peripheral devices are the same as those in FIG. 9, and the description thereof will be omitted here.

As shown in FIG. 1, the inside of the incinerator main body 10 includes, in order from the bottom, a primary combustion region (gasification region) A1,
Secondary combustion area (main combustion area) A2 and tertiary combustion area A
There are three categories. A lower throttle portion 12 protrudes at a boundary between the primary combustion region A1 and the secondary combustion region A2, and an upper throttle portion 14 protrudes at a boundary portion between the secondary combustion region A2 and the tertiary combustion region A3. An air supply device (air supply means) 15 is connected to each of the throttle portions 12 and 14.

The inner peripheral surface of the lower throttle portion 12 is, in order from the lower end, a tapered surface 16 having a diameter decreasing upward, a cylindrical surface 17 having a constant diameter, and a taper surface 18 increasing diameter upward. ing. As shown in FIG. 2A, a large number of secondary air injection ports 20 are provided on the cylindrical surface 17 in a circumferential direction, and air supplied from the air supply device 15 is supplied to each of the secondary air injection ports 20. And is injected into the incinerator as secondary air (auxiliary combustion air). Here, the injection direction of the secondary air is at an appropriate angle (here, about 30
°) Inclined upward and at a suitable angle to the radial direction in the cross section as shown in FIG.
However, they are set in directions in which they are inclined in the same direction, that is, directions in which the secondary air is supplied while turning.

The inner peripheral surface of the upper throttle portion 14 is composed of a tapered surface 22 whose diameter decreases upward and a taper surface 24 whose diameter increases upward in order from the lower end. As shown in FIG. 2B, a plurality of (four in the illustrated example) tertiary air injection ports 26 are provided at equal intervals in the circumferential direction in the upper throttle section 14, and each tertiary air injection port is provided. A number of secondary tertiary air injection ports 28 are provided between the air supply ports 26, and the air from the air supply device 15 is injected as tertiary air (auxiliary combustion air) into the incinerator through these injection ports 26, 28. It is supposed to be.

Here, the third air from the tertiary air injection port 26 is
The injection direction of the secondary air is inclined downward by an appropriate angle with respect to the horizontal direction in the vertical section as shown in FIG.
In the cross section shown in (b), the direction is set to match the radial direction. Specifically, when the penetration force (the force reaching the waste incinerator against the flow of the rising gas) is strong, the angle in the vertical plane including the central axis of the incinerator is about 0 ° with respect to the radial direction. A range of 60 ° is appropriate, and is approximately 45 ° in the illustrated example.

The third tertiary air injection ports 28
The injection direction of the next air is set to match the horizontal direction in the vertical section as shown in FIG. 1 and to the radial direction in the cross section as shown in FIG. 2B.

That is, the internal shape of the incinerator in the secondary combustion region A2 is set to a shape in which the diameter increases at the inlet portion upward and decreases at the outlet portion upward.

In such an incinerator, dust is thrown into a sand layer (not shown) in the primary combustion area A1, and the dust burns, gasifies, and enters the secondary combustion area A2.

In the secondary combustion air A2, secondary air is injected in a swirling state from a secondary air injection port 20 of the lower throttle portion 12, which is an inlet portion thereof, rises while expanding in a radial direction, and then exits. The tapered surface 2 of the upper throttle portion 14
At 6, it is narrowed down to the center. Further, 3
When the tertiary air is injected downward from the secondary air injection port 26, a recirculation vortex (that is, a gas flow that turns downward at the outlet portion after ascending) is formed together with the secondary air. The recirculation vortex effectively mixes the secondary air and the tertiary air with the combustion gas that has risen from the primary combustion area A1, whereby the combustion gas is satisfactorily reburned. The gas generated by this combustion floats in the tertiary combustion area A3 and is discharged outward from the upper part of the incinerator.

As described above, in this incinerator, the throttle portions 12 and 14 are provided at the entrance and exit of the secondary combustion area A2, and the secondary air and the tertiary air are injected from both the throttle portions 12 and 14 to make the secondary air. Since the recirculation vortex is formed in the combustion area A2, the gasified refuse is sufficiently mixed with the secondary air and the tertiary air (auxiliary combustion air) by using the recirculation vortex, The generation of dioxin can be significantly suppressed.

In particular, in this embodiment, since the secondary air is introduced in a swirling state, the formation of the recirculation vortex becomes easier, and the flow in the second combustion zone A2 is complicated, and the mixing is further promoted. There are advantages. The tertiary combustion area A3
Is also in a swirling state, so that there is an advantage that the residence time in this area A3 can be lengthened.

Further, in this embodiment, since the tertiary air is injected downward from the tertiary air injection port 26, the gas in the secondary combustion area A2 is prevented from blowing upward from the center, and a stronger power is provided. Recirculation vortices can be formed and 3
3 from the secondary tertiary air injection port 28 between the secondary air injection ports 26
By injecting the next air, the blow-by can be prevented more reliably.

Here, for the formation of the recirculation vortex, it is particularly important to reduce the passage by the tapered surface 22 and to inject downward tertiary air at the outlet of the secondary combustion region. Tapered surface 2
If there is no passage reduction due to 2, the formation of vortices is not promoted, and if there is no downward tertiary air injection, gas containing intermediate products generated in the primary combustion area A1 blows through the center of the incinerator. This is because sufficient mixing cannot be performed.

FIGS. 3 and 4 show the CO in the conventional incinerator shown in FIG. 9 and the CO in the incinerator of this embodiment shown in FIG.
3 shows the result of calculating the mixed state and the velocity vector of the gas by numerical flow calculation. Referring to these figures, the recirculation vortex is hardly formed inside the conventional incinerator, and the mixed state of CO is poor. On the other hand, in the incinerator according to the present embodiment, the recirculation vortex clearly appears in the secondary combustion region. It can be understood that CO is sufficiently mixed with the secondary air and the tertiary air by the recirculation vortex.

FIG. 10 shows the conventional type and the present embodiment type.
It shows the results of a combustion test in a 5 ton / day model furnace. In this model furnace, a city gas burner is used without a sand layer. However, the carbon monoxide emissions and CO2 emissions when the combustion operation is performed under the same conditions as an actual furnace with a sand layer (fluidized bed municipal solid waste incinerator) The simulation is performed to obtain the temporal pattern. More specifically, first, a conventional model furnace was searched for a combustion operation method that generates the same amount of carbon monoxide emission and its temporal pattern as that of a conventional actual furnace, and thereafter, the same operation method as this combustion operation method was used. The combustion operation is performed in the model furnace of this embodiment by the method, and the result is measured.

It should be noted that "rated conditions" in the figure mean design conditions, and therefore, under these operating conditions, the amount of carbon monoxide generated is zero for both types. On the other hand, “local low load condition” means the operating condition in a state where the waste is exhausted, and “local overload condition” means the operating condition in a state where the waste is locally excessively supplied. ing.

As shown in the figure, as a result of the above test, according to the model furnace of the present embodiment, the amount of carbon monoxide emission was 1/100 of that of the conventional model furnace under the local high load condition.
It was found that carbon monoxide emission could be reduced to almost zero under local low load conditions. this is,
This is considered to be because the unburned gas and the auxiliary combustion air are favorably mixed in the secondary combustion region in the recirculation vortex in the furnace of the present embodiment.

Next, a second embodiment will be described with reference to FIG.

In the incinerator shown in the first embodiment, the recirculation vortex is more easily formed as the gas passage is rapidly expanded by the tapered surface 18 of the lower narrowed portion 12. An increase in the degree of restriction of the tapered surface 16 increases the flow velocity of the main flow excessively, so that vortex formation becomes difficult on the contrary.

Therefore, in the second embodiment, the incinerator main body 10 is provided at the inlet and outlet of the second combustion zone A2.
The inner diameter of the incinerator in the second combustion area A2 is actually larger than the inner diameter of the incinerator in the other areas A1 and A3. With such a configuration, the gas passage can be rapidly expanded at the entrance of the second combustion region A2 without restricting at the exit of the first combustion region A1. It can be easily formed.

Next, a third embodiment will be described with reference to FIG.

Here, the central axis G1 of the furnace in the primary combustion area A1 is changed to the central axis G2 of the furnace in the secondary combustion area A2.
From the primary combustion area A1
The upper surface of the housing forming the upper part is opened upward, and a dust inlet 34 is provided on the upper surface.

With this structure, as shown in the first and second embodiments, the central axis G1 of the primary combustion area A1 and the central axis G2 of the secondary combustion area A2 coincide with each other. As compared with the structure, there is obtained an advantage that the dust inlet 34 can be closer to the central portion of the primary combustion area A1. Even if the two regions A1 and A2 are eccentric as described above, the recirculation vortex is stably formed in the secondary combustion region A2, so that sufficient mixing of the combustion gas and the auxiliary combustion air and reduction of dioxin can be achieved. Can be planned.

Next, a fourth embodiment will be described with reference to FIG.

The fluidized bed incinerator shown in each of the above embodiments is
Because of excellent load followability (that is, high responsiveness to temperature fluctuations in the furnace due to dust input), particularly in the secondary combustion region A2 in which combustion by active mixing is achieved, and in the tertiary combustion region A3 downstream thereof, , And easily exceeds the preferable temperature range (800 to 1000 ° C in the above embodiment). Due to such an excessive rise in temperature, thermal NOx or melting of fly ash on the wall surface may occur, and the performance of the incinerator may be reduced.
Further, about 2% of the heat generated in the furnace is wasted from the furnace wall to the outside of the furnace, and it is desired to recover the heat.

Therefore, in this embodiment, a water cooling jacket is provided on the furnace wall to cool the inside of the furnace and recover heat.

More specifically, in FIG. 7, cooling jackets 36 and 38 having donut-shaped spaces are formed in the side walls surrounding the secondary combustion area A2 and the tertiary combustion area A3. Each of the cooling jackets 36 and 38 is connected to a pump (flow means) 40 via a cooling water supply passage 39 and to a tank (not shown) via a hot water recovery passage 42.

In the main body of the waste incinerator, the secondary combustion zone A2
And thermocouples (temperature detecting means) 44 and 46 for detecting the temperature in the furnace in the tertiary combustion region A3,
A flow control device 48 for controlling the water discharge flow rate of the pump 40 based on the detected temperatures of the thermocouples 44 and 46 is provided. The flow control device 48 includes the thermocouple 44,
When at least one of the detected temperatures 46 exceeds the maximum allowable temperature (1000 ° C. in this embodiment), the water discharge flow rate of the pump 40 is configured to be higher than the basic flow rate.

According to such a configuration, the temperature inside the furnace is kept at an appropriate temperature by the cooling water flowing in the cooling jackets 36 and 38, and the heat generated in the furnace is recovered using the cooling water as a medium ( Specifically, hot water heated by the heat in the furnace can be collected in a tank), and the heat of the hot water can be reused for heating the incineration plant premises. Specifically, in an incinerator with a waste disposal rate of 100 t / day, warm water of about 80 ° C.
r It has been confirmed that recovery is possible.

This embodiment can be modified as follows.

(A) The cooling jackets 36 and 38 may be formed only in one of the secondary combustion area A2 and the tertiary combustion area A3. However, if provided in the tertiary combustion region A3, the temperature of the combustion gas discharged from the incinerator outlet 50 can be more reliably suppressed to a specified temperature or lower.

(B) In FIG. 7, the cooling jackets 36 and 38 are used.
Is shown with a common pump 40 connected thereto, but the pump 40 is individually connected to each jacket 36, 38,
The water discharge flow rate of each pump 40 may be individually controlled based on the furnace temperature in each of the regions A2 and A3.

(C) The cooling fluid flowing through the cooling jackets 36, 38 is not limited to water. For example, air is allowed to flow through the jackets 36, 38, and the warmed air is converted into secondary air or tertiary air. It may be used for air.

The present invention is not limited to the embodiments described above, but may take the following forms as examples.

(1) In the present invention, the air ratio of the gas flowing into the secondary combustion area A2 may be appropriately set, but the air ratio should be maintained at about 1.7 in order not to lower the combustion temperature. It is highly desirable to set the direction and momentum of the air supply so as to form a stable recirculation vortex.

Furthermore, if the secondary air or tertiary air is mixed with water vapor or atomized water having a higher specific gravity than these air and injected, the motion of the water-mixed air is increased by the weight without increasing the injection speed. The energy can be increased, whereby the penetration force of the secondary air or the tertiary air, that is, the force for penetrating the rising gas against the flow and reaching the center of the furnace can be increased.

(2) In the present invention, the air ratio in the secondary combustion region may be set as appropriate. However, it is preferable to adjust the air ratio so that a high temperature of about 1000 ° C. can be maintained in this region, and to determine the momentum of the air so as to form the recirculation vortex within the range of the air amount. Is highly desirable.

(3) In the present invention, the specific temperature of the auxiliary combustion air is not limited. However, if the auxiliary combustion air is preheated before being introduced, it is possible to avoid cooling of the incinerator due to the introduction. And better combustion can be ensured.

(4) In the present invention, it is sufficient that the downward auxiliary combustion air having a penetrating force is supplied at the outlet side of the second combustion region A2, and the tertiary combustion region A3 in the above embodiment can be omitted. . However, by setting the tertiary combustion area A3, the gas burned in the secondary combustion area A2 can be kept in the incinerator for a longer time, and the combustion that cannot be sufficiently performed only by promoting the mixing is also performed favorably. It becomes possible. For example, even when a substance requiring time for combustion such as charcoal or soot is generated in the combustion gas, or when the amount of oxygen and the amount of fuel supplied are small, the gas burned in the secondary combustion region A2 is tertiary. By keeping the combustion area A3 for a predetermined time or longer, complete combustion can be achieved.

(5) In the present invention, a cross section taken along the line AA and the line BB shown in FIG. 1, for example, is shown in FIGS. Even if it is rectangular, a recirculation vortex is formed in the same manner as in the previous embodiment by expanding and reducing the gas passage at the entrance and exit of the secondary combustion area A2 and by appropriately introducing auxiliary air. be able to. Also, as shown in FIG. 3A, the secondary air can be supplied while swirling by inclining the jetting direction of the secondary air in the horizontal plane.

(6) In the present invention, the direction of the recirculation vortex is not particularly limited. For example, when the free board has a rectangular cross section as shown in FIGS. 8A and 8B, the air supply structure 21 penetrates a pair of wall surfaces facing each other in the depth direction as shown in FIG. The lower surface is a tapered surface 22 for restricting, and the tertiary air injection ports 26 and the secondary tertiary air injection ports 28 provided at both ends of the air supply structure 21 are provided in the same manner as in the first embodiment. By supplying the auxiliary combustion air, it is possible to form a recirculation vortex that rotates in the reverse direction to the recirculation vortex shown in FIG.

[0066]

As described above, the present invention provides a secondary combustion region .
By injecting auxiliary combustion air downward at the outlet
A recirculation vortex is formed in the same area, and the mixing efficiency of the auxiliary combustion air and the gasified waste is enhanced by the recirculation vortex. There is an effect that discharge can be significantly suppressed.

In particular, in the incinerator according to claim 4, the above-mentioned 2
Since the auxiliary combustion air is injected while being swirled at the entrance of the next combustion region, there is an effect that the recirculation vortex can be more easily formed.

Further, in the incinerator according to the fifth aspect, the above-mentioned 2
The shape of the outlet part of the secondary combustion area is set so that the gas passage becomes narrower as it goes upward, so that the rapid expansion of the gas passage promotes the formation of recirculation vortices and clarifies the secondary combustion area. By doing so, there is an effect that auxiliary air supplied below the outlet of the secondary combustion region is prevented from flowing into the primary combustion region, and the recirculation vortex can be stabilized.

Furthermore, in the waste incinerator according to the seventh aspect, the gas burned in the secondary combustion region is allowed to stay in the tertiary combustion region on the way to the outlet of the incinerator, so that it can be burnt like charcoal. Even when a substance requiring time is contained in the combustion gas or when the amount of oxygen and the amount of fuel supplied are small, there is an effect that sufficient combustion in the furnace can be ensured.

Further, in the waste incinerator according to the sixth and eighth aspects, a cooling fluid is circulated in a cooling jacket formed in the side wall of the incinerator surrounding the secondary combustion region and the tertiary combustion region. As a result, it is possible to prevent the furnace temperature from rising excessively and to ensure normal combustion. In addition, the heat generated in the furnace can be recovered using the cooling fluid as a medium, thereby realizing energy saving.

Here, in the waste incinerator according to the ninth aspect, the flow rate of the cooling fluid is controlled based on the actual furnace temperature, so that the furnace temperature is more accurately maintained in an appropriate range. be able to.

Further, in the method according to the tenth aspect, since steam having a higher specific gravity or atomized water having a higher specific gravity is mixed into the auxiliary combustion air, the kinetic energy of the mixed gas and the penetrating energy of the mixed gas are increased by this mass increase. The force (the force with which the auxiliary combustion air penetrates the rising gas against the flow to the center of the waste incinerator) can be increased, thereby enabling formation of a stronger recirculation vortex and adjustment of the vortex intensity. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a sectional front view showing a main part of a waste incinerator according to a first embodiment of the present invention.

2A is a cross-sectional view taken along the line AA of FIG. 1, and FIG.
FIG. 7 is a sectional view taken along line BB of FIG.

FIG. 3 is a diagram showing a result of calculating a CO mixing state and a gas velocity vector in a conventional waste incinerator.

FIG. 4 is a diagram showing a result of calculating a mixed state of CO and a velocity vector of gas in the waste incinerator of the embodiment.

FIG. 5 is a sectional front view showing a main part of a waste incinerator according to a second embodiment of the present invention.

FIG. 6 is a sectional front view showing a main part of a waste incinerator according to a third embodiment of the present invention.

FIG. 7 is a sectional front view showing a main part of a waste incinerator according to a fourth embodiment of the present invention.

8 (a) and 8 (b) are cross-sectional plan views showing a modification of the planar cross-sectional shape of the waste incinerator of the present invention.

FIG. 9 is a sectional front view showing an example of a conventional waste incinerator.

FIG. 10 is a graph showing test results of flammability in a conventional incinerator and an incinerator of the present invention.

FIG. 11 is a sectional front view showing a modified example of the internal shape of the waste incinerator according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Incinerator main body 12 Lower throttle part 14 Upper throttle part 15 Air supply device (air supply means) 20 Secondary air injection port 26 Tertiary air injection port 30 Large diameter part 32 Reduced diameter part 36, 38 Cooling jacket 40 Pump (Flow means) 44, 46 Thermocouple (temperature detection means) 48 Flow control device (flow control means) A1 First combustion area A2 Second combustion area A3 Third combustion area

Continuation of the front page (72) Inventor Hiroaki Kawabata 1-3-18, Wakihama-cho, Chuo-ku, Kobe Kobe Steel, Ltd. Kobe Head Office (56) References JP-A-4-214109 (JP, A) JP 50-57936 (JP, A) JP-A-5-240416 (JP, A) JP-A 62-202925 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23G 5 / 14 F23G 5/44 F23G 5/50

Claims (10)

(57) [Claims] 1. A waste incinerator that burns waste supplied therein, gasifies the waste, and discharges the waste to the outside. A primary combustion zone in which the waste is burned and gasified is provided. Forming a secondary combustion region located above the primary combustion region and further burning the gas generated in the primary combustion region, and assisting downward at an outlet portion of the secondary combustion region.
Disposal by a waste incinerator characterized in that by injecting combustion air, a recirculation vortex of gas is formed in the secondary combustion area, which upwardly flows from an inlet portion thereof and turns downward just before an outlet portion. Incineration method. 2. A waste incinerator that burns waste supplied therein, gasifies and discharges the waste to the outside, and includes therein a primary combustion region in which the waste is burned and gasified. Forming a secondary combustion zone located above the primary combustion zone and further burning the gas generated in the primary combustion zone;
An air supply means for supplying auxiliary combustion air to the inside of the waste incinerator, and a gas recirculation vortex flowing upward from the inlet portion and downward before the outlet portion in the secondary combustion region. also set the supply point and the feed direction of the auxiliary combustion air by the internal shape and the air supply means incinerator in the secondary combustion region so as to form a
And the air supply means is provided at an outlet of the secondary combustion zone.
A waste incinerator characterized by injecting auxiliary combustion air downward at a part thereof. 3. The waste incinerator according to claim 2, wherein
The internal shape of the incinerator in the secondary combustion region is set to a shape in which the gas passage is reduced upward at the outlet portion of the secondary combustion region, and the air is provided at the inlet portion and the outlet portion of the secondary combustion region. A waste incinerator wherein a supply point of the auxiliary combustion air by the supply means is set, and a supply direction of the auxiliary combustion air supplied at the outlet portion is set downward. 4. The waste incinerator according to claim 3, wherein
A waste incinerator characterized in that the direction of the auxiliary combustion air supplied at the inlet of the secondary combustion area is set so as to swirl. 5. The waste incinerator according to claim 3, wherein the internal shape of the inlet portion of the secondary combustion area is set to have a shape in which the gas passage expands upward. Incinerator. 6. The waste incinerator according to claim 2, wherein a cooling jacket is formed in a side wall of the incinerator surrounding the secondary combustion area, and a cooling jacket is provided in the cooling jacket. A waste incinerator comprising a distribution means for flowing a fluid. 7. The refuse incinerator according to claim 2, wherein the gas burned in the secondary combustion area stays between the secondary combustion area and the incinerator outlet. A waste incinerator characterized by forming an area. 8. The waste incinerator according to claim 7, wherein
A waste incinerator comprising: a cooling jacket formed in a side wall of the incinerator surrounding the tertiary combustion region; and a distribution means for flowing a cooling fluid through the cooling jacket. 9. The waste incinerator according to claim 6, wherein a temperature detecting means for detecting a temperature inside the furnace, and the flow means based on the temperature detected by the temperature detecting means, the inside of the cooling jacket being provided by the flow means. And a flow rate control means for controlling a flow rate of a cooling fluid flowing through the waste incinerator. 10. The waste incinerator according to claim 3, wherein steam or atomized water is mixed into the auxiliary combustion air. Method.