JPH102676A - Air-diffusing nozzle for fluidized bed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an air-diffusing nozzle from falling off and enable replacement of the diffuser nozzle while a fluidized bed is being operated. SOLUTION: A cylindrical air-diffusing nozzle 1 is detachably screwed by means of a thread structure on an air distributing duct 5 disposed within a fluidized medium bed in a furnace or on a diffuser plate disposed in a bottom portion within the furnace and air (a) is blown into the fluidized medium bed to fluidize the fuidized medium and a top of the nozzle has a closed structure. A plurality of air jetting holes 1d tangentially directed in a same circumferential direction are formed in a vicinity of the top of the air-diffusing nozzle 1, and the air-diffusing nozzle 1 is turned to tighten the thread structure by a reaction force induced by jetting of the air (a) through the jetting holes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized bed incinerator for incineration of municipal solid waste and various kinds of wastes. The present invention relates to an improvement of an air diffusion nozzle for a fluidized bed in which a fluid is caused to flow.

[0002]

2. Description of the Related Art In general, fluidized bed combustion is difficult because of the high heat content of a fluidized medium such as silica sand or limestone that forms a fluidized bed. It has been widely used since it can burn even flammable materials and can also co-fire two or more types. That is, fluidized bed combustion includes coal, lignite, solidified fuels such as wood, paper, plastic, and RDF; various woody wastes such as bark, chip, and sawdust; Agricultural waste, other various industrial wastes, municipal waste, various sludges, etc. can be satisfactorily burned.

FIG. 5 is a schematic vertical sectional view showing a main part of a fluidized bed incinerator for performing fluidized bed combustion. The fluidized bed incinerator is made of silica sand, limestone or the like formed at the bottom of a furnace body 20. A large number of air diffusing nozzles 2 are provided in a fluid medium layer 21 made of a fluid medium.
A plurality of air distribution ducts 23 provided in parallel with each other are arranged in parallel in a horizontal state, air is blown from the air diffusion nozzle 22 into the fluid medium layer 21 to cause the fluid medium to flow, and the fluid medium layer 21 is covered with the air. Combustion products (municipal waste, various wastes, etc.) are supplied and fluidly burned.

As shown in FIGS. 6 and 7, the diffuser nozzle 22 is formed in a cylindrical shape whose top is closed by a metal material having excellent heat resistance and wear resistance. A plurality of air ejection holes 22a extending radially from the axis center position
And a female screw 22 is provided on the inner peripheral surface at the lower end.
b is formed.

[0005] The air diffuser nozzle 22 is connected to the air distribution duct 2.
3 is detachably attached to the upper surface side at a predetermined interval. That is, as shown in FIG. 6, the diffuser nozzle 22 is provided on the upper surface of an air distribution duct 23 made of a square pipe.
A tubular nozzle 24 having a male screw 24a to be screwed with the second female screw 22b is fixed by welding, and the female screw 22b of the air diffuser nozzle 22 is screwed to the male screw 24a of the nozzle 24. Thereby, it is detachably attached to the air distribution duct 23.

[0006]

The diffusion nozzle 22 in the fluidized bed incinerator is buried in the fluidized bed 21 and flows violently during the operation of the fluidized bed incinerator. The problem of wear is inevitable. For this reason, the diffuser nozzle 22 is usually 5
They had to be replaced on a yearly cycle. In addition, there is a risk that the diffuser nozzle 22 may be loosely connected to the nozzle 24 and fall off from the air distribution duct 23 due to micro-vibration during operation of the fluidized bed incinerator. Therefore, when attaching the air diffuser nozzle 22 to the air distribution duct 23, it was necessary to sufficiently tighten the air diffuser nozzle 22 to the nozzle 24 side.

However, the air diffusion nozzle 22, which is tightly attached to the nozzle 24, is exposed to a high temperature, so that the joint (screw portion) with the nozzle 24 is seized and can be easily removed. Often there was no state. In particular, in a large fluidized bed incinerator, the number of diffuser nozzles 22 is large, and reaches several hundred to 1,000 per furnace.
When the air diffusion nozzle 22 causes the above-described burn-in phenomenon, a large amount of labor and time are required to replace the air diffusion nozzle 22.

As described above, in the conventional air diffusion nozzle 22, if the air diffusion nozzle 22 is loosely fastened to the nozzle 24, the seizure phenomenon hardly occurs and the air diffusion nozzle 22 can be easily replaced. On the other hand, there is a problem that the air diffusing nozzle 22 easily falls off from the air distribution duct 23. On the contrary, if the air diffusing nozzle 22 is strongly fastened to the nozzle 24, the air diffusing nozzle 22 On the other hand, it is possible to prevent the falling off of the nozzles, but on the other hand, there arises a problem that the seizure phenomenon occurs and the replacement of the diffusing nozzle 22 cannot be easily performed, and both conflicting problems cannot be solved at the same time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to prevent a fall of a diffuser nozzle, and to make it possible to replace a diffuser nozzle easily and easily. It is intended to provide a layer diffusion nozzle.

[0010]

In order to achieve the above object, the present invention provides a screw structure on an air distribution duct disposed in a fluidized medium layer in a furnace or on a dispersion plate disposed at a bottom in the furnace. In a tubular fluidized bed diffusion nozzle which is detachably screwed and has a closed top for blowing air into the fluidized medium layer to allow the fluidized medium to flow, near the top of the diffused nozzle A plurality of air ejection holes which are directed in the same circumferential direction and tangentially, and the air diffusion nozzle is rotated in a direction of tightening a screw by a reaction force generated when air is ejected from each air ejection hole. It is what was constituted.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a partially cutaway perspective view showing an example of a fluidized-bed incinerator using a diffuser nozzle 1 for a fluidized-bed according to the present invention. The fluidized-bed incinerator has a rectangular shape in which a combustion chamber 2 is formed inside. Furnace body 3 and a fluidized medium layer 4 made of a fluidized medium such as silica sand or limestone formed on the bottom of the furnace body 3
A plurality of square pipe air distribution ducts 5 arranged in parallel in the fluid medium layer 4 in a horizontal posture;
A large number of diffusing nozzles 1 attached at regular intervals on the upper surface side of the furnace, a wind box 6 arranged outside the furnace and connected to the end of each air distribution duct 5, and a combustion exhaust gas outlet of the furnace body 3 The boiler 7 and the like provided in the above are provided, and the structure other than the air diffusion nozzle 1 is the same as that of a conventionally known structure.

In FIG. 1, reference numeral 8 denotes an outlet for a fluid medium and incombustibles formed at the bottom of the furnace main body 3; A supply port 10 for supplying a substance to be burned, such as a substance, is disposed in the fluidized medium layer 4, and constitutes a part of a heat transfer tube of the boiler 8.
Reference numeral 11 denotes an air supply duct connected to the wind box 6.

In the fluidized bed incinerator, air is supplied from a ventilator (not shown) to each air distribution duct 5 through an air preheater (not shown), an air supply duct 11 and a wind box 6. The air a having an appropriate temperature is ejected from the air diffusion nozzle 1 into the fluidized medium layer 4. by this,
In the portion of the fluidized medium layer 4 above the air distribution duct 5, the fluidized medium is caused to flow by the air a ejected from the air diffusing nozzle 1, and a fluidized bed is formed. Further, in the portion of the fluid medium layer 4 below the air distribution duct 5, the fluid medium is stopped without being affected by the flow action of the air a ejected from the diffusion nozzle 1, and a storage layer is formed. . The air “a” jetted from the air diffusion nozzle 1 is used not only for flowing the fluid medium but also as primary combustion air.

On the other hand, burnable materials such as municipal solid waste and various wastes are crushed, crushed, fixed-quantity feeders, supply conveyors, and the like.
It is fed into the furnace from a supply port 9 via a supply feeder (both not shown). Most of the combustibles introduced into the furnace are stirred vigorously in a fluidized bed flowing at high temperature,
Fluid combustion is performed by the air a ejected from the air diffusion nozzle 1 and the secondary combustion air supplied to the combustion chamber 2. In addition, some extremely lightweight combustible waste and ash from the fluidized bed are discharged from the combustion chamber 2
Floating combustion.

The high-temperature flue gas G generated by the combustion is recovered by the boiler 7 and then discharged to the atmosphere via an air preheater, an exhaust gas treatment device and a chimney (all not shown). The fluid medium containing incombustibles is sequentially pulled out from the discharge port 8, and after removing incombustibles using a vibrating screen (not shown), the fluid medium is conveyed by a conveyor (not shown) and formed on the side wall of the furnace body 3. It has been re-introduced into the furnace through a fluid medium inlet (not shown).

As shown in FIGS. 2 and 3, the air diffusing nozzle 1 of the present invention is formed in a cylindrical shape whose top is closed by a metal material having excellent heat resistance and abrasion resistance. 5 is detachably screwed onto the base 5 by a screw structure.

That is, the air diffusing nozzle 1 is composed of a cylindrical tube portion 1b having a female screw 1a formed on the inner peripheral surface of the lower end portion, and a blind plate 1c connected to the upper end of the tube portion 1b and closing the upper end opening. The outer peripheral surface of the upper end portion of the air diffusion nozzle 1 is formed in a hexagonal shape. Further, on the upper surface of the air distribution duct 5, air outlets 5a are formed at regular intervals along the longitudinal direction, and around the air outlets 5a, the female outlets 1a of the air diffuser nozzle 1 are screwed. A cylindrical nozzle 12 having an external thread 12a is fixed by welding with the external thread 12a facing upward. Therefore, the air diffuser nozzle 1 is detachably attached to the air distribution duct 5 by screwing the female screw 1 a into the male screw 12 a of the nozzle 12.

As shown in FIGS. 3 and 4, air a supplied to the air distribution duct 5 is supplied to the fluid medium layer 4 near the top of each of the diffusing nozzles 1 (portion formed in a hexagonal shape). A plurality of air ejection holes 1d for blowing into the inside are formed at equal angles in the same circumferential direction and in the tangential direction. Therefore, when the air a is ejected from the air ejection hole 1d, a reaction force is generated in each of the diffusing nozzles 1 so that a rotational force in a direction opposite to the direction in which the air a is ejected (the diffusing nozzle 1 shown in FIG. 4). In the case of, a clockwise rotation force) acts. At this time, the direction of each air ejection hole 1d is set such that the direction of the rotational force generated by the reaction force is the direction in which the air diffusion nozzle 1 is tightened toward the nozzle 12. In addition, since the air ejection hole 1d is formed in the hexagonally formed portion of the air diffusion nozzle 1, even if the air ejection hole 1d faces in the tangential direction, the air ejection hole 1d is connected to the air diffusion nozzle 1d. Can be easily and easily drilled.

As described above, since each of the air diffusion nozzles 1 is rotated in a direction in which the screw is tightened by a reaction force generated when air a is jetted from each of the air jet holes 1d, fluidized bed incineration is performed. The nozzle 1
It does not mean that the connection with the cable 2 is loosened and drops off from the air distribution duct 5. Therefore, when the air diffusion nozzle 1 is attached, it is not necessary to perform excessive tightening to prevent the air diffusion nozzle 1 from falling off. As a result, the diffusing nozzle 1 and the nozzle 1
It is possible to prevent sticking due to seizure of the connecting portion (screw portion) with the nozzle 2, and it is possible to easily and easily remove the air diffusion nozzle 1 when replacing the air diffusion nozzle 1.

In the above example, the outer periphery of the upper end portion of the diffusing nozzle 1 is formed in a hexagonal shape, but in other examples,
The outer periphery of the upper end portion of the diffusion nozzle 1 may be formed in an octagonal shape, a circular shape, or the like.

In the above example, the air diffusion nozzle 1 is detachably attached to the air distribution duct 5 made of a square pipe. In other examples, the air diffusion nozzle 1 is made of a round pipe. It may be detachably attached to the air distribution duct 5 with a screw structure, or an inclined dispersion plate (not shown) in which the diffusion nozzle 1 is arranged at the bottom of the furnace and supports the fluidized medium layer (4). You may make it attach detachably by a screw structure above.

In the above example, the diffuser nozzle 1 is connected to the nozzle 1
The air diffusion nozzle 1 is detachably attached to the air distribution duct 5 via the air distribution duct 5, but in another example, the air diffusion nozzle 1 is detachably screwed directly to the air distribution duct 5 or the distribution plate. Is also good.

In the above example, the air diffusing nozzle 1 is formed with six air ejection holes 1d which face counterclockwise, but the number and direction of the air ejection holes 1d are limited to the above example. However, it is possible to obtain a good fluid combustion by flowing a fluid medium, and to attach the diffuser nozzle 1 to the nozzle 1
The number and direction are arbitrary as long as a rotational force in the direction of tightening to the two sides can be generated.

[0024]

As described above, the present invention provides a plurality of air streams in the same circumferential direction and tangential direction near the top of an air diffusion nozzle detachably screwed on an air distribution duct or a distribution plate. The fluidized bed incinerator is formed by forming the ejection holes and rotating the diffusion nozzle in the direction tightened toward the air distribution duct side by the reaction force generated when air is ejected from each air ejection hole It is possible to reliably prevent the air diffusion nozzle from falling off during the operation of (1). In addition, it is possible to easily and easily remove the air diffusion nozzle when replacing the air diffusion nozzle. That is, when installing the air diffuser nozzle, it is not necessary to strongly tighten the air diffuser nozzle to the air distribution duct side, it is sufficient only to tighten by hand, and it is not necessary to tighten a large number of air diffuser nozzles using a tool. Of course, since the air diffusion nozzle can be loosely tightened, seizure of the air diffusion nozzle can be prevented, and it is not difficult to remove the old air diffusion nozzle due to seizure when replacing the air diffusion nozzle. As a result, the operation of replacing the diffuser nozzle becomes extremely simple and easy without requiring much labor and time to replace the diffuser nozzle.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing an example of a fluidized-bed incinerator using a fluidized-bed aeration nozzle of the present invention.

FIG. 2 is a side view of a state in which the air diffusion nozzle for a fluidized bed of the present invention is attached to an air distribution duct via a nozzle.

FIG. 3 is a longitudinal sectional view showing a state in which the air diffuser nozzle is attached to an air distribution duct via a nozzle.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a schematic vertical sectional view of a main part of a fluidized bed incinerator using a conventional diffuser nozzle.

FIG. 6 is a longitudinal sectional view showing a state in which a conventional air diffusion nozzle is attached to an air distribution duct via a nozzle.

FIG. 7 is a sectional view taken along the line BB of FIG. 6;

[Brief description of reference numerals]

1 is a diffuser nozzle, 1d is an air ejection hole, 4 is a fluidized medium layer,
5 is an air distribution duct, and a is air.

Claims (1)

[Claims] 1. A fluid medium layer which is detachably screwed by a screw structure onto an air distribution duct (5) arranged in a fluid medium layer (4) in a furnace or on a dispersion plate arranged in a bottom portion in the furnace. (4) In a tubular fluidized-bed diffusion nozzle (1) having a closed top for blowing air (a) into the fluidized medium, the top of the diffusion nozzle (1) In the vicinity, a plurality of air ejection holes (1d) which are directed in the same circumferential direction and tangential direction are formed, and the air diffusing nozzle (1) emits air (a) from each air ejection hole (1d). Characterized in that the nozzle is rotated in a direction in which the screw is tightened by a reaction force generated in the nozzle.