JP2746317B2 - Fuel dispersion device for fluidized bed combustion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel dispersing apparatus for a fluidized-bed incinerator or a fluidized-bed boiler for burning liquid waste such as a waste liquid from a chemical plant or CWM or CWS.

[0002]

2. Description of the Related Art The present applicant has previously filed Japanese Patent Application No. 2-418202.
In the above item, when a liquid fuel such as a waste liquid discharged from a chemical plant is combusted by a fluidized bed combustion device such as a fluidized bed incinerator, the liquid fuel is mixed with air in a substantially horizontal direction in a fluidized bed, and The liquid fuel on the freeboard above the fluidized bed (especially its volatiles, etc.) A) A fuel dispersing device for improving the combustion efficiency of liquid fuel by reducing the combustion ratio of (1) has been proposed.

FIG. 3 shows the structure of this fuel distribution device. In this figure, a fuel dispersing device 30 is mounted on a partition plate 16 of a gas dispersing plate 12 above an air chamber 11 so as to be positioned in a fluidized bed 20, and is erected at a central portion to form a fuel ejection nozzle 32 at a tip. And an air supply pipe having a lower end fixed to the partition plate 16 of the gas distribution plate 12 around the liquid fuel supply pipe 31 and an upper end formed with an air ejection nozzle 34 around the fuel ejection nozzle 32. 33, and a fuel distribution cap 35 that surrounds the air ejection nozzle 34 and the fuel ejection nozzle 32 and is fixed to the upper portion of the air supply pipe 33. The liquid fuel supply pipe 31 is supported and fixed to the partition plate 16 by a bracket 31a.

The lower end of the liquid fuel supply pipe 31 is connected to a fuel supply pump (not shown). The fuel dispersing cap 35 is formed such that an inner wall surface (ceiling surface) above the openings of the fuel ejection nozzle 32 and the air ejection nozzle 34 has a spherical shape with a central portion projecting upward, and an air supply pipe 33.
The entire peripheral wall is connected to a horizontal bottom plate 35a fixed to the upper part of the main body to form a dome shape.

A plurality (four in this example, four at 90 ° intervals) of fuel dispersing nozzles 36 are provided circumferentially below the fuel dispersing cap 35 at a position above the upper surface of the bottom plate 35a by a predetermined distance above the upper surface of the bottom plate 35a. Are mounted horizontally. The fuel dispersion nozzle 36 has a predetermined length in the axial direction and protrudes outward from the outer surface of the side peripheral wall, so that the fluid medium 21 enters the fuel dispersion nozzle 36 when the fluid medium 21 is not fluidized when the operation is stopped. It is prevented from flowing. A large number of the fuel dispersing devices 30 having such a configuration are attached to the gas dispersing plate 12 so as to be evenly and uniformly supplied to the fluidized bed 20. The gas dispersion plate 12 includes the fuel dispersion device 3
A number of air dispersion tubes (not shown) are attached in parallel with 0,
The fluidizing operation of the fluid medium 21 is performed by the air dispersion tube.

In such a configuration, the gas distribution plate 12
In the upper combustion chamber 13, a fluid medium 21 such as sand is fluidized by high-temperature air to form a fluidized bed 20 having a high temperature. Then, liquid fuel as waste liquid such as lactam extraction residue having a temperature of, for example, about 100 ° C. is sent to a liquid fuel supply pipe 31 of the fuel dispersing device 30 by a supply pump (not shown). At the same time as air is ejected upward, air is supplied from the air chamber 11 to the air supply pipe 33.
The fuel is sprayed toward the center of the fuel jet nozzle 32 obliquely upward from the air jet nozzle 34 above the air jet nozzle 34.
At this time, the air is ejected from the periphery of the fuel toward the center of the fuel ejection nozzle 32, so that the fuel and the air are ejected upward while being mixed.

[0007] The mixed air and fuel collide with the spherical ceiling surface of the fuel dispersing cap 35 and are reversed and descend downward, and a part of the liquid fuel is vaporized into vapor. . These liquid fuel, vapor and air flow into four fuel dispersing nozzles 36 on the side peripheral wall, and are vigorously discharged by the action of air from the fluid dispersing nozzles 36 into the fluidized bed 20 radially about the fuel dispersing cap 35 as a center. Fluidized bed 2 is supplied evenly and evenly into the fluidized bed 20.
In 0, local combustion and local heating are prevented and combustion is performed efficiently.

The volatile matter in the fuel is burned after the moisture is evaporated. However, by dispersing and supplying the fuel into the fluidized bed 20 from multiple points, the fuel is dispersed in the fluidized bed 20 having a large heat capacity. Is instantaneously evaporated, and the volatiles are burned after a short time. Therefore, the burning rate of the volatiles in the fluidized bed 20 is increased, and the burning rate of the free board 13a is reduced.

[0009]

As described above, in the fuel dispersing device 30, the liquid fuel can be efficiently burned in the fluidized bed 20, while, in FIG. 3, for example, the fuel dispersing cap 35 is inclined. For example, the right fuel distribution nozzle 36 on the right side in the figure is lowered when the fuel distribution nozzle 36 on the right side in the figure is inclined at a lower position than the fuel distribution nozzle 36 on the left side. The fuel is spouted from the center. In addition, this tendency is such that the vertical center line of the fuel ejection nozzle 32 does not coincide with the vertical center line passing through the vertex of the fuel distribution cap 35, and the fuel ejection nozzle 32 is mounted so as to be shifted. This tendency is particularly pronounced when the distance 36 is shorter than the distance between the fuel distribution nozzle 32 and the left fuel distribution nozzle 36. When the fuel dispersing cap 35 is lower on the right side in the figure, the amount of liquid fuel accumulated on the bottom plate 35a increases, and the fuel dispersing nozzle 3 on the right side at a position lower than this point also.
The ratio of fuel ejected from 2 increases.

As described above, when the mounting accuracy of the fuel distribution nozzle 30 is poor, there is a problem that the liquid fuel to be burned is not uniformly dispersed from the plurality of fuel distribution nozzles 36 around the fuel distribution cap 35. Even when the fuel is not uniformly ejected from the fuel dispersing nozzles 36 around the fuel dispersing cap 35, the air is uniformly dispersed from the surrounding fuel dispersing nozzles 36. In the fluidized bed 20, some fuel is burned and moisture in the fuel is evaporated, and the main combustion is performed on the freeboard above the fluidized bed 20. The combustion ratio in 20 becomes worse. Also,
As a result, when the liquid fuel is a liquid fuel having a large amount of water or a liquid fuel having a low calorie, the temperature of the fluidized bed 20 does not rise.

The present invention has been made in view of the above-described problems, and has been made in such a manner that liquid fuel (including liquid incineration such as waste liquid) can be uniformly dispersed in a fluidized bed and burned efficiently. It is an object of the present invention to provide a fuel dispersion device for a fluidized bed combustion device.

[0012]

In order to achieve the above object, the present invention provides: (1) a fluidized bed combustion apparatus for burning a liquid fuel in a fluidized bed formed by fluidizing a fluidized medium with air; A fuel dispersing device, wherein a plurality of air dispersing nozzles are arranged radially around an air supply pipe by branching the air supply pipe in a horizontal direction or a substantially horizontal direction from the air supply pipe; A fuel supply pipe is attached inside the fuel supply pipe, and a fuel distribution nozzle is provided around the fuel supply pipe, the fuel supply pipe being branched from the fuel supply pipe, and the opening directed toward the opening direction of the air distribution nozzle at a position corresponding to each of the air distribution nozzles. At the same time, the opening of the fuel dispersing nozzle is located in the air dispersing nozzle so that the fuel and air are ejected and dispersed from the air ejecting nozzle into the fluidized bed, and the air dispersing nozzle adjacent in the circumferential direction is
The main feature of the lug is that its openings are located on the circumference of different radii . Also,

[0013]

[0014]

With the configuration as described in (1) above, the air supplied to the air supply pipe is radiated from a plurality of air distribution nozzles around the air supply pipe to the air supply pipe as a center and in a horizontal or almost horizontal direction. The fluid is discharged and dispersed in the direction, and the fluidized medium is fluidized to form a fluidized bed. Further, when the liquid fuel is supplied to the fuel supply pipe in this state, the liquid fuel flows into the respective fuel distribution nozzles provided by branching from the fuel supply pipe at positions corresponding to the respective air distribution nozzles. It is discharged into the air distribution nozzle from the tip opening and is dispersed in the fluidized bed together with air.

However, in this case, the plurality of air distribution nozzles are attached by branching from the air supply pipe, and the plurality of fuel distribution nozzles are also attached by branching from the fuel supply pipe. The liquid fuel and the air are surely divided and flow into the plurality of dispersion nozzles, respectively, and the liquid fuel and the air are uniformly dispersed in the fluidized bed from the plurality of surrounding air dispersion nozzles and burned. For this reason, the discharge of the liquid fuel from the air distribution nozzle in the biased portion is prevented, the combustion ratio in the freeboard is reduced, the combustion ratio of the liquid fuel in the fluidized bed is improved, and the temperature of the fluidized bed is increased. Will be kept.

Since the tip opening of the fuel dispersing nozzle is located in the air dispersing nozzle, the liquid fuel is discharged from the air dispersing nozzle, so that the liquid fuel is put on the air flow flowing in the air dispersing nozzle. It is reliably transported and is reliably ejected into the fluidized bed together with air from the air distribution nozzle opening.
Accordingly, for example, even when the air flow rate during low load combustion is small, the fuel is prevented from dripping into the air supply pipe as much as possible, and the inside of the air supply pipe and the air chamber and the like connected thereto are prevented from being contaminated with the fuel. That is, even when the air flow rate is low during low load combustion, the predetermined air flow rate is maintained in the air distribution nozzle, so that the liquid fuel is reliably sent to the front opening side, and the liquid fuel is supplied to the air supply pipe of the air distribution nozzle. Is prevented from flowing toward the branch point, ie, the air inlet, and dripping from the air inlet into the air supply pipe.

Further, when a liquid fuel having a high calorific value is burned, the fluidized bed temperature is maintained at a predetermined temperature due to the heat generated by the combustion of the fuel itself, so that auxiliary combustion (burning by a burner) in the air chamber is unnecessary. However, in such a case, the air in the air chamber and air supply pipe is at room temperature and not high temperature, so if the liquid leaks here, it will not evaporate and adhere to the air supply pipe. However, as described above, since the liquid is prevented from dripping from the air inlet of the air supply pipe into the air supply pipe, such a trouble is also prevented.

Further, the air distribution nozzles adjacent in the circumferential direction are
The openings are located on the circumference of different radii
As a result, the distance between the openings of the air distribution nozzles adjacent in the circumferential direction becomes longer, the coalescence of the air bubbles ejected from the respective air distribution nozzles is prevented, and the air blows through in the fluidized bed. That is, the formation of the air passage is prevented, and the fluid medium such as sand is fluidized uniformly. Therefore, the fuel does not blow upward with the air, and the combustion of the fuel on the freeboard is also prevented. Therefore, the fuel
The uniform distribution of the fuel and air in the fluidized bed is ensured, and the combustion efficiency in the fluidized bed is further improved. When the openings of the air distribution nozzles adjacent in the circumferential direction are arranged on the same circumference, the distance between the openings of the adjacent air distribution nozzles becomes short, and the air ejected from the openings and the air are easily united. As a result, large bubbles are blown upward as they are and are discharged to the freeboard, so that uniform fluidization is not performed and the rate of fuel combustion on the freeboard increases. For this reason, the combustion efficiency in the fluidized bed deteriorates, and the temperature of the fluidized bed cannot be kept high.

[0019]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view (sectional view taken along line II of FIG. 2) showing an embodiment of a fuel dispersion device for a fluidized bed incinerator of the present invention, and FIG. 2 is a sectional view taken along line II-II of FIG. FIG. The same or corresponding parts as those in FIG. 3 are denoted by the same reference numerals, and description thereof is omitted.

The fuel supply device 40 is configured such that the air supply pipe 41 is connected to the upper partition plate 15a and the lower partition plate 15 of the gas distribution plate 15 in a state where the upper air distribution nozzle 42 is located in the fluidized bed 20 in the combustion chamber 13. 15b. The lower end of the air supply pipe 41 is open facing the air chamber 11, and high-temperature air is taken into the air supply pipe 41 from the air chamber 11. The gas distribution plate 15 is formed by an upper partition plate 15a and a lower partition plate 15b, and an air passage 15e formed between both of them for cooling the gas distribution plate. 1
5c and 15d are refractories such as castables.

The upper end of the air supply pipe 41 is connected to an annular lid 4 described later.
3 and the liquid guide cover 47. Annular lid 43
At a position immediately below the air supply pipe 41, an air distribution nozzle 42 is branched off from the air supply pipe 41 and protrudes at a predetermined length in the horizontal direction. As shown in FIG. A plurality (12 in the present embodiment, at equal intervals in the circumferential direction) are arranged radially from the center of the tube 41. The opening 42a and the opening 42 of the air distribution nozzle 42 adjacent in the circumferential direction are provided.
a is located on a circle having a different radius from the center of the air supply pipe 41, that is, in this embodiment, adjacent air distribution nozzles 42 have different lengths.

On the other hand, a fuel supply pipe 45 is disposed at a central portion inside the air supply pipe 41, and a top of the fuel supply pipe 45 is formed with a funnel-shaped enlarged portion 45a having a funnel-shaped cross section.
A plurality of fuel dispersing nozzles 46 are attached to the periphery of the vertical wall at the upper end of the fuel dispersing nozzle 46 so as to branch off from the vertical wall and protrude in the horizontal direction.
Are directed in the same direction as the opening 42a of the air distribution nozzle 42, and as shown in FIG.
Twelve pieces are mounted at equal intervals in the circumferential direction corresponding to the mounting positions. Then, the opening 46 of the fuel distribution nozzle 46
a is located in the air distribution nozzle 42 at a position closer to the opening 42 a side than the position of the air inlet of the air distribution nozzle 42.

The diameter (outer diameter) of the fuel dispersion nozzle 46
Are formed smaller than the diameter (outer diameter) of the air dispersion nozzle 42, and as shown in FIG.
Reference numeral 6 is attached to the air distribution nozzle 42 so that its axis is aligned in plan view. In this embodiment, the fuel dispersion nozzle 4
Numeral 6 is screwed and attached to the vertical wall of the enlarged diameter portion 45a, and is formed so as to be easily assembled.
The fuel dispersing nozzle 46 is attached by grasping the opening 46a side of the fuel dispersing nozzle 46 with a jig (not shown), passing it through the air dispersing nozzle 42 and screwing it into the vertical wall.

At the upper end of the enlarged diameter portion 45a of the fuel supply pipe 45, a lid (hereinafter referred to as a liquid guide lid) 47 having a lower surface 47a formed in a truncated inverted conical shape and also serving as a liquid guide is fixedly attached. The lower surface 47a is provided with a guide passage 4 for uniformly feeding the fuel between the enlarged diameter portion 45a of the fuel supply pipe 45 and the fuel distribution nozzles 46 located in the circumferential direction.
5b.

A flange 47b having an outer diameter smaller than the inner diameter of the air supply pipe 41 is formed around the upper end of the liquid guide lid 47. The liquid guide lid 47 is formed between the lower surface of the flange 47b and the upper end of the air supply pipe 41. 20% ring (ring shape) between
Is supported in a state where the lid 43 is sandwiched. Therefore, the fuel supply pipe 45 is also supported by the annular lid 43. Of course,
After assembling, the joint between the split surface S of the annular lid and the flange 47b and the annular lid 43, and the annular lid 43 and the upper end of the air supply pipe 41 are sealed by welding or the like.

As shown in FIG. 1, the lower part of the fuel supply pipe 45 is horizontally bent inside the air chamber 11, and a flange 48 is attached to an end thereof.
Is connected to the flange 51 of the pipe 50 communicating with the fuel supply source, the fuel is supplied to the fuel supply pipe 45, rises in the pipe, and is ejected from the fuel dispersion nozzle 46 at the tip. Although not shown, a predetermined number of the fuel dispersing devices 40 having such a configuration are attached to the gas dispersing plate 15 so as to be evenly and uniformly supplied to the fluidized bed 20.

Next, the fuel dispersing device 40 having such a configuration will be described.
The operation of will be described. From the air chamber 11, for example, when the temperature is 800
High-temperature air of about 900 ° C. is taken into the air supply pipe 41 of the fuel dispersing device 40 from its lower end opening, rises and reaches the top, and is guided by the lower surface of the enlarged diameter portion 45 a of the upper fuel supply pipe 45 ( The guide is guided toward the inner wall side of the air supply pipe 41, and flows uniformly into each of the air distribution nozzles 42 that are branched and attached thereto, and enters the combustion chamber 13 through the openings 42a. Distributed and supplied. Combustion chamber 1
In 3, the high temperature air fluidizes the fluid medium 21 such as sand, and the fluid medium 21 is heated to, for example, 80 μm.
A hot fluidized bed 20 of 0-950 ° C. is formed.

The high-temperature air is used not only for fluidizing the fluid medium 21 but also as fuel combustion air. Further, the dispersed supply of the high-temperature air into the combustion chamber 13 and the dispersed supply of the liquid fuel to be described later into the combustion chamber 13 are similarly performed from a large number of fuel dispersion devices 40 attached to the gas dispersion plate 15. . Air chamber 1
In order to keep the temperature of the fluidized bed 20 substantially constant, the temperature of the high-temperature air 1 is low when the calorific value of the fuel to be incinerated is high, and is high when the calorific value of the fuel is low.

With the high temperature fluidized bed 20 thus formed, the liquid fuel (for example, waste liquid as a lactam extraction residue having a temperature of about 100 ° C.) is supplied to a fuel supply source by a supply pump (not shown). The pipe 50 is fed from the pipe 50 to the fuel supply pipe 45 and rises inside the fuel supply pipe 45 to reach the enlarged diameter portion 45a at the top. In the enlarged diameter portion 45a, the fuel is smoothly guided to the outer peripheral side of the enlarged diameter portion 45a along a guide passage 45b formed between the fuel guide lid 47 and the lower surface 47a of the liquid guide lid 47 formed in a truncated inverted conical shape. The fuel is uniformly introduced into the plurality of fuel dispersion nozzles 46 located on the outer periphery, and is ejected from the openings 46 a into the air dispersion nozzle 42. The fuel ejected into the air dispersion nozzle 42 is carried on the high-temperature air flowing through the air dispersion nozzle 42, mixed with the air, and flowed toward the opening 42a.
It is distributed and supplied to inside 0.

The fuel sent from the pipe 50 connected to the fuel supply source to the fuel supply pipe 45 at about 100 ° C. is heated by the high-temperature air (for example, 800 to 900 ° C.) in the air chamber 11 so that the fuel becomes liquid. A part of the liquid supply pipe 45 evaporates while moving up the vertical part of the supply pipe 45, and further flows into the guide passage 45b of the enlarged diameter part 45a. Heated by the fluidized bed 20 to a high temperature (for example, 800 to 950 ° C.) (the heat of the hot fluidized bed 20 is transferred to the liquid guide lid 4 via the lid 43 at the top of the air supply pipe 41).
7), in the guide passage 45b, the fuel is heated from both sides of the lower surface 47a of the liquid guide cover 47 and the inclined wall on the lower surface of the enlarged diameter portion 45a, and the heat transfer area here is reduced. Due to the large size, the effect of evaporating the fuel is further promoted. For this reason, the combustion is performed early when the air exits the air dispersion nozzle 42, and the combustion is reliably performed in the fluidized bed 20.

Thus, an equal amount of fuel is radially ejected from each of the plurality of air distribution nozzles 42 together with the air.
The fuel is dispersed and the variation in the amount of fuel ejected from each air dispersing nozzle 42 is suppressed, and the residence time in the fluidized bed 20 is extended by being ejected and dispersed in the horizontal direction. Therefore, the combustion of the fuel and the evaporation of the water in the fuel in the fluidized bed 20 are equally performed for each air distribution nozzle 42, and
Sufficiently, the combustion ratio in the freeboard is reduced, the combustion ratio in the fluidized bed 20 is improved, and the fluidized bed 20 is kept at a high temperature.

Further, since the fuel is ejected from the air dispersion nozzle 42, the fuel is reliably carried by the air and supplied to the fluidized bed 20 from the opening 42a of the air dispersion nozzle 42, and the low load combustion with a small amount of fuel processing is performed. Even at this time, since the air flow velocity in the air distribution nozzle 42 is maintained at a predetermined flow velocity, the fuel is sent together with the air to the opening 42a side without flowing to the air inflow side. Therefore, it is possible to avoid falling down into the air supply pipe 41 or down there and into the air chamber 11.

Further, when incinerating a fuel having a high calorific value, the temperature of the fluidized bed 20 is maintained at a predetermined high temperature.
The auxiliary combustion in the air chamber is not required, and it is sufficient to supply the normal temperature air.
Since the fuel is ejected in the inside 2 and is ejected from the opening 42a into the fluidized bed 20, the fuel is prevented from falling to the air supply pipe 41 side and does not remain in the air chamber 11 or the like in a liquid state. That is, if the liquid drops when the air is at room temperature, the dropped liquid is not evaporated and the contamination becomes severe, but this is not the case.

In the present invention, the position of the opening 46a of the fuel distribution nozzle 46 is located at least closer to the inside of the air distribution nozzle 42 than the position of the air inlet of the air distribution nozzle 42. If the position of the opening 46a of the fuel dispersion nozzle 46 is too close to the side of the opening 42a of the air dispersion nozzle 42, mixing with air is deteriorated, and the opening 46a is easily exposed to the high temperature of the fluidized bed 20, and It is not preferable because heavy oil etc. may be clogged and clogged,
Preferably, the position is as close to the air inlet as possible.

On the other hand, the air distribution nozzles 42 adjacent in the circumferential direction
Are located not on a circle of the same radius but on a circle of a different radius, and the distance between the openings 42a and 42a of the adjacent air distribution nozzles 42 is long,
The coalescence of the air bubbles (bubbles) ejected from the openings 42a of the respective air dispersion nozzles 42 is prevented, and the blow-through of the air in the fluidized bed, that is, the formation of the air path is prevented, and the fluid medium 21 is removed. It is fluidized uniformly. Therefore, the fuel does not blow up with the air, and the fluidized bed 20 does not flow.
Combustion of the fuel in the free board, which is the space above, is efficiently prevented. Therefore, the combustion efficiency in the fluidized bed 20 is further improved.

The air distribution nozzles 42 adjacent in the circumferential direction
Are arranged on the same circumference, that is, when the air distribution nozzles 42 have the same distance from the center of the air supply pipe 41 to the opening 42a, the distance between the openings 42a of the adjacent air distribution nozzles 42 and the opening 42a Close to the opening 42a
The air ejected from the opening 42a and the air are easy to unite, become large bubbles as they are, blow out upward and are discharged to the free board, and uniform fluidization is not performed. The rate at which fuel burns increases. For this reason, the combustion efficiency in the fluidized bed 20 deteriorates, and the temperature of the fluidized bed 20 cannot be maintained at a high temperature.

The flue gas of the fuel burned in the fluidized bed 20 is discharged from the fluidized bed 20 and rises on the freeboard, and is discharged from an exhaust gas outlet (not shown) to the outside of the incinerator to collect the exhaust heat and collect dust. Served for action.

In the above embodiment, the case where the air dispersion nozzle 42 and the fuel dispersion nozzle 46 are provided in the horizontal direction has been described. However, as long as the fluidization of the fluidized bed 20 is not impeded, It may be provided slightly downward or upward, for example, within a range where the residence time can be kept long in the fluidized bed 20.

As described above, the fuel dispersing apparatus 40 of the present invention uses a fluidized bed to burn and incinerate a liquid such as a waste liquid of a chemical plant in a fluidized bed, or heats a heat transfer tube by a heated fluidized bed. It can be suitably used for a fluidized bed combustion device such as a fluidized bed boiler for obtaining steam. If CWS (cold water slurry) or CWM (cold water mixture) is used as the liquid fuel of the fluidized bed boiler, the fuel handling is simplified as compared with a coal-fired fluidized bed boiler, and a compact boiler is realized by fluidized bed combustion and heat transfer. can do.

[0040]

As described above, according to the present invention,
According to the structure of the first aspect, the liquid fuel can be uniformly and uniformly dispersed and supplied into the fluidized bed from the plurality of air dispersion nozzles of the fuel supply device together with the air, so that the fuel is locally supplied to the fluidized bed. In addition, it is possible to prevent local combustion and local heating, and prevent combustion on the free board, thereby improving the combustion ratio in the fluidized bed, and to constantly maintain the temperature of the fluidized bed at a high temperature suitable for combustion. Therefore, liquid fuel can be stably burned, for example, by reducing additional firing for maintaining a fluidized bed temperature in an air chamber or the like.

Further, since the liquid fuel and air are mixed in the air dispersion nozzle, the contact between the fuel liquid and oxygen is improved, the combustion speed in the fluidized bed is increased, and the combustion rate in the fluidized bed is reduced. Can be more enhanced. Further, since the liquid fuel is ejected in the air dispersion nozzle and put on the air flowing in the air dispersion nozzle, the fuel is reliably ejected and supplied into the fluidized bed, so that combustion can be surely performed, and Even during load combustion, it is possible to prevent the liquid fuel from flowing into the air supply pipe or the air chamber and to be contaminated, and to smoothly operate the combustion device.

Even if the fuel contains a large amount of volatile components, the volatile components are dispersed and supplied to multiple points in the fluidized bed, so that the moisture can be quickly evaporated and the volatile components can be burned.
The rate of combustion in the fluidized bed can be increased by minimizing escape of volatiles to the free board. In addition, since liquid fuel such as waste water of a high water content can be stably burned in the fluidized bed, the supply amount of auxiliary fuel such as heavy oil for supplying to the burner of the air chamber to replenish the heat of water evaporation can be reduced. .

Further, it is possible to prevent the coalescence of the air bubbles (bubbles) ejected from the respective air dispersion nozzles, to prevent the air from blowing through the fluidized bed, that is, to prevent the formation of the air path, and to prevent the fluid medium from flowing. It can be fluidized uniformly. Therefore, fuel without blown upward together with the air, before
Ensure that the fuel and air described above are evenly distributed in the fluidized bed.
Thus, the combustion of fuel in the freeboard can be prevented, and the combustion efficiency in the fluidized bed can be further improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view (sectional view taken along line II of FIG. 2) showing an embodiment of a fuel dispersion device for a fluidized bed incinerator of the present invention.

FIG. 2 is a plan view taken along line II-II in FIG.

FIG. 3 is a longitudinal sectional view showing a conventional fuel distribution device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Air chamber 13 Combustion chamber 15 Gas dispersion plate 20 Fluidized bed 21 Fluid medium 40 Fuel distribution device 41 Air supply pipe 42 Air distribution nozzle 42a Opening (air distribution nozzle) 43 Annular lid 45 Fuel supply pipe 45a Enlarged diameter part (Fuel supply pipe) 45b Guide passage (liquid fuel) 46 Fuel distribution nozzle 46a Opening (fuel distribution nozzle) 47 Liquid guide lid 47a Inverted conical lower surface

Claims (1)

(57) [Claims] 1. A fuel dispersing device for a fluidized bed combustion device for burning a liquid fuel in a fluidized bed formed by fluidizing a fluidized medium with air, comprising a plurality of fuel dispersing devices around an air supply pipe. The air distribution nozzles are arranged radially by branching from the air supply pipe in the horizontal direction or almost horizontal direction, and the fuel supply pipe is attached inside the air supply pipe and branched from the fuel supply pipe around the fuel supply pipe. A fuel distribution nozzle having an opening directed toward the opening direction of the air distribution nozzle is provided at a position corresponding to each of the air distribution nozzles, and the opening of the fuel distribution nozzle is located in the air distribution nozzle. and fuel and air to be ejected dispersed from the air jet nozzle into the fluidized bed, the air adjacent in the circumferential direction
The dispersing nozzle has an opening on the circumference of different radii.
A fuel dispersing device for a fluidized bed combustion device, characterized in that it is in a position .