JPH01259090A - Nozzle for blasting gasifying agent into fluidized bed gasification furnace for coals - Google Patents

Abstract

PURPOSE:To provide the subject nozzle for the fluidization of coals, free from the trouble of clogging with deposited molten coal, positioned at the lower stage part of a fluidized bed-forming zone of a fluidized bed gasification furnace for coals, horizontally protruded through the furnace wall toward the center line and having a tip opening directing slantly upward. CONSTITUTION:A nozzle 21 for blowing a gasification agent into a lower stage of a furnace is horizontally extended through a furnace wall 23 at the lower stage of a fluidized bed-forming zone A of a fluidized bed gasification furnace for coals and protruded toward the center line X of the zone A. The opening 2 at the tip end 1 of the nozzle 21 is opened toward the center line X of the zone A directing slantly upward. Coal is supplied into the gasification furnace through a coal-feeding nozzle 22 slantly extended through the furnace wall 23 and directing toward the center line X. The coal is fluidized with the gasification agent blown through the lower-stage blowing nozzle 1 to form a fluidized bed. The formation of sintered part at the tip end of the nozzle can be prevented and the coal gasification can be smoothly performed by the use of the nozzle.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention introduces a gas for forming a fluidized bed into the furnace body from the bottom of the furnace body through a perforated plate or without passing through a perforated plate. forming a bed, and blowing a gasifying agent into at least the lower part of the fluidized bed forming area,
A gasification reaction is carried out in this zone, and coal gasified materials are extracted from the empty column above the fluidized bed formation zone, while solid content of gasification residue is extracted from the bottom of the furnace body to perform fluidized bed gasification of coal. Fluidized bed gasification of coal has been significantly improved by overcoming the technical deficiencies of the conventional nozzle in the lower blowing nozzle for blowing the gasifying agent into the lower part of the coal fluidized bed gasifier. The present invention relates to a gasifying agent lower-stage blowing nozzle structure that makes it possible to perform the following steps.

More specifically, the present invention provides a gasifying agent lower blower which is installed horizontally in the lower part of the fluidized bed forming area of the coal fluidized bed gasifier, penetrating the furnace wall and protruding in the direction of the center line of the area. A gasifying agent injection nozzle structure for a coal fluidized bed gasifier, characterized in that the nozzle has a tip opening opening in the direction of the center line of the area and diagonally upward. relating to things.

Conventionally, a fluidized bed of coal is formed by introducing gas for forming a fluidized bed into the furnace body from the bottom of the furnace body through a dispersion plate (a porous straightening plate for forming a fluidized bed), and at least the lower part of the fluidized bed formation area. A dispersion plate type coal fluidized bed gasifier in which a gasification agent is injected into the lower stage (for example, the lower stage or the lower and middle stages) and the gasification reaction is carried out in the area, and furthermore, without using a dispersion plate, A jet type coal fluidized bed gasifier, which introduces a gas jet for forming a fluidized bed from the bottom of the furnace body to form a fluidized bed of coal in the furnace body, and similarly injects a gasifying agent to perform a gasification reaction. Coal fluidized bed gasifiers such as the following are known.

In such conventional gasifiers, a gasifying agent, typically containing air and/or oxygen and steam, is blown into at least the lower section of the fluidized bed formation zone through the lower blowing nozzle. A gasification reaction is carried out in the gasification reaction, and a gasification agent lower injection nozzle is known as the lower injection nozzle, which is installed horizontally through the furnace wall of the gasification furnace and protrudes in the direction of the center line of the area. ing. However, in such a lower stage gasifying agent injection nozzle, molten ash adheres and grows around the nozzle tip, which hinders the normal and smooth supply and operation of gasifying agent injection. This occurs in a short period of time, and furthermore, the falling off of lumps of molten ash that have grown and fixed can cause problems such as clogging of the mouth of the dispersion plate, failure to extract the gasification residue solids, blockage, and other troubles.

In order to avoid such troubles, in jet-type coal fluidized bed gasifiers, a lower gasifying agent injection nozzle is installed horizontally, penetrating the furnace wall and protruding in the direction of the center line of the fluidized bed forming area. There is a known proposal in JP-A-59-117586 to remove the molten ash that adheres and grows by providing a mechanical scraping means before the above-mentioned troubles occur.

In this proposal, JP-A No. 52-12
Introducing the proposal of No. 6404, the lower blowing nozzle protruding into the furnace in the distributed plate type coal fluidized bed gasifier disclosed in the prior art still causes fusion of molten ash during long-time operation. It points out that there is a technical defect that cannot avoid the trouble that occurred. In the proposal of JP-A No. 59-117586, in a jet type coal fluidized bed gasifier, continuous or intermittent vibration is applied to the gasifying agent lower injection nozzle, or, We proposed a jet-type coal fluidized bed gasifier that removes molten ash before it becomes too fixed and grows by adding mechanical removal means such as designing the outer circumference of the nozzle so that the pipe can move. ing.

However, this proposal inevitably involves new technical deficiencies, such as disadvantages in the device of providing the mechanical removal means and disadvantages in the operation of operating the means. In addition, in conventional gasifiers, for example, it is virtually impossible to attach mechanical means to the gasifier under high temperature and high pressure, and molten ash grows at the tip of the nozzle protruding into the furnace. It is also difficult to directly detect the shape and size of the object. Furthermore, in the conventional gasifier as described above, it is also difficult to control the amount of molten ash.

The present inventors have proposed a gasifying agent lower blowing nozzle that is installed horizontally in the lower part of the fluidized bed forming area of a coal fluidized bed gasifier, penetrating the furnace wall and protruding in the direction of the center line of the area. Research has been carried out to develop a nozzle structure for injecting a coal-based fluidized bed gasifying agent that can overcome the deficiencies of the prior art as described above.

As a result, the opening at the tip of the lower gasifying agent blowing nozzle, which conventionally opened in the direction perpendicular to the center line of the fluidized bed formation area, has been changed from opening in the direction of the center line of the area and diagonally upward. It has been discovered that the above-mentioned deficiencies of the prior art can be solved at once by designing the device to satisfy the simple structural change of opening.

Furthermore, by designing the opening at the tip of the lower gasifying agent blowing nozzle as described above, it has become possible to directly supply the gasifying agent into the fluidized bed. Therefore, the gasifying agent can be dividedly supplied into the fluidized bed through the opening, thereby supplying a higher concentration of oxygen into the furnace than in the conventional distributed plate type coal fluidized bed gasifier. It has become clear that as a result, the temperature inside the furnace can be made higher and more uniform, and the cold gas efficiency and reliability, which will be described later, are improved.

Accordingly, the present invention provides a lower stage injection nozzle structure for gases and other agents for a coal fluidized bed gasifier, which enables the fluidized bed gasification of coal to be carried out industrially with remarkable advantage.

The above objects and many other objects and advantages of the present invention will become more apparent from the following description.

The lower-stage injection nozzle structure for other gases and other agents for a coal fluidized bed gasifier of the present invention can be applied to either the above-mentioned dispersion plate type or jet type coal fluidized bed gasifier. Since it is particularly suitable for application to a lower blowing nozzle structure for gases and other agents for a plate-type coal fluidized bed gasifier, this embodiment will be mainly described in detail below with reference to the accompanying drawings.

FIG. 1 of the accompanying drawings is a side sectional view showing an example of the lower blowing nozzle structure for gases and other agents for a coal fluidized bed gasifier according to the present invention, and FIG. It is a partially cutaway I; implicit cross-sectional view showing one aspect of the curing furnace.

In the example of FIG. 2, the distribution plate (perforated plate for fluidized bed formation) 20
The gas for forming a fluidized bed is introduced from the bottom of the furnace body surrounded by the furnace wall 23 (a in the figure).
, forming a fluidized bed of coal. Coal, for example in the form of slurry raw coal powder, is atomized by steam via a coal feed nozzle 22 into the fluidized bed formation zone Δ, which in this example is introduced into an interruption of the zone. A gasifying agent is blown into at least the lower part (for example, the lower part or the lower part and the middle part) of the area Δ through the lower blow nozzle 21 to perform a gasification reaction in the area Δ. In the example of FIG. 2, a middle blowing nozzle 21' for gases and other agents is also provided at the interrupted part of the area Δ, and these lower and middle blowing nozzles 21, 21' penetrate the furnace wall 23 and pass through the area. The nozzle is provided horizontally so as to protrude in the direction of the center line X of Δ, and the tip opening of the nozzle is open in the direction perpendicular to the center line X. In the example shown in FIG. 2, the coal supply nozzle 22 is provided diagonally through the furnace wall 23 so as to spray the coal slurry in the direction of the center line X and diagonally upward. There is.

The coal gasified product produced by the gasification reaction is taken out from the empty column (shown with a - part notched away) above the upper surface A' of the fluidized bed formation area Δ, while the solid content of the gasification residue is taken out from the furnace. It is extracted from the bottom of the body via the residue extraction passage 24 (mouth in the figure).

The lower blowing nozzle 21, the middle blowing nozzle 21', and the coal supply nozzle 22 are usually provided in a plurality of positions facing each other in the direction of the center line X so that the supply flows collide with each other. Although two nozzles are shown in each example, it goes without saying that more than two nozzles may be provided.

The present invention penetrates the furnace wall 23 of a gasifier, such as the one shown in FIG. This invention relates to an improvement in a horizontally installed gasifying agent blowing nozzle.

The lower blowing nozzle structure for other gases and other agents for a coal fluidized bed gasifier of the present invention penetrates the furnace wall 23 into the lower part of the fluidized bed forming area Δ of the coal fluidized bed gasifier. A lower blowing nozzle for gases and other agents is provided horizontally so as to protrude in the direction of the center line of the nozzle 21, and as shown in a side sectional view of an example of the nozzle in FIG. Area Δ
It is characterized by opening in the direction of the center line X and diagonally upward. This feature will be explained in more detail with respect to the example shown in FIG.

The lower blowing nozzle 21 for gases and other agents of the present invention is provided horizontally, penetrating the furnace wall 23 and protruding in the direction of the center line X of the fluidized bed forming area Δ. Here, the term "horizontally projected in the direction of the center line" refers not only to the case where the nozzle protrusion axis Y is perpendicular to the center line X of the area Δ, as shown in FIG. This is meant to include cases where they are nearly orthogonal to each other. For example, in the figure, the angle θ1 is 90
A range such as 80° to 100° including the case where it is 0,
Preferably, this includes cases where they intersect within a range of 90°±5°.

Further, in the lower blowing nozzle 21 for gases and other agents of the present invention, the opening 1 at the tip 2 of the nozzle opens in the direction of the center line X of the fluidized bed forming area A and diagonally upward. here,
"In the direction of the center line of the area and diagonally above" means:
As shown in FIG. 1, the tip 2 of the nozzle protrusion
Not only when the axis Y' intersects the center line X of the fluidized bed formation area Δ, but also to the extent that the extension of a cylinder whose axis is the axis Y' and whose diameter is the diameter of the tip opening l intersects the center line X. In the direction of the center line, which includes the case of deviation, and in the figure θ
The angle indicated by is less than 90°, for example, 50° to 70°
, preferably obliquely upward, meaning an angle such as 60°±5°.

In the gasifying agent lower stage blowing nozzle 21 of the present invention, the nozzle is provided so as to project horizontally in the direction of the center line of the fluidized bed forming area.

In the fluidized bed formation zone, particles near the furnace wall have less kinetic energy than particles located in the center of the furnace. Therefore, a zone where particles are easily trapped is formed near the inner wall surface of the furnace in the fluidized bed forming area. Therefore, if the lower gasifying agent injection nozzle provided on the wall of the fluidized bed formation area does not protrude from the wall, the oxygen in the gasifying agent blown from the nozzle and the particles in the retention area will cause a combustion reaction. However, since the heat is not sufficiently diffused, a cylindrical protruding sinter is formed at the tip of the nozzle.

In contrast, the nozzle of the present invention protrudes from the wall surface and its nozzle opening extends to the area where the kinetic energy of the particles is large, so that the above-mentioned protruding sinter is not formed.

According to the present invention, the nozzle of the present invention projects preferably from about 3 to about 100 cm, more preferably from about 7 to about 30 cm, from the inner surface of the furnace wall in the direction of the furnace centerline.

In addition, in the fluidized bed formation area, if the gasifying agent lower blowing nozzle is not made to protrude in the direction of the furnace center line, but is made to protrude in the tangential direction of the furnace that is far away from the center line, the amount of gas injected from the nozzle If this value fluctuates, the flow and mixing state of the particles in the fluidized bed will become unstable and not constant, which is inappropriate.

Furthermore, a region with a high concentration of particles is formed in which the flow of particles is not uniform at the back surface of the nozzle that protrudes in the tangential direction of the furnace, which is also unsuitable. Therefore, it is impossible to achieve stable gasification of coal when the gasifying agent lower blowing nozzle is made to protrude in the tangential direction.

In contrast, according to the present invention in which the gasifying agent lower blowing nozzle protrudes in the direction of the center line, the gasifying agent from the nozzle opening is blown out in the direction of the furnace center line and flows upward into the center of the fluidized bed area. A stable fluidized bed is formed without disturbing the flow (movement) of the entire fluidized bed. According to the present invention, in particular, by installing the blowing nozzles at opposite positions on the furnace wall, the gas blown from each nozzle collides at the center of the furnace. This is suitable because it forms a flow.

Furthermore, the tip opening of the nozzle of the present invention is provided so as to open in the direction of the center line of the fluidized bed forming area and diagonally upward.

If the tip opening of the gas injection nozzle provided in the fluidized bed area is opened perpendicularly in the direction of the furnace center line, the gasifying agent will be blown in from the nozzle perpendicular to the furnace center line. This injection of gasifying agent intersects with the particle stream rising upward from the bottom of the gasifier. As a result, a dense accumulation of particles is formed below the tip of the nozzle, and in this accumulation, the heat generated by the combustion reaction between the oxygen from the nozzle and the particles is poorly diffused, causing the tip of the nozzle to A plate-like sinter is formed in the lower part. Such plate-shaped sinter is particularly noticeable in the lower part of the furnace where the upward flow is strong.

In contrast, the opening at the tip of the nozzle of the present invention is opened diagonally upward toward the center line, so that the gasifying agent can stably flow inside the furnace without disturbing the movement of particles in the fluidized bed area. is blown into the air and smoothly reacts with the particles to achieve gasification.

To explain further, the gasifying agent jetted obliquely upward by the nozzle of the present invention further activates the movement of particles in the furnace, strengthens the upward flow, achieves smooth circulation of particles in the furnace, and Since the entire temperature is raised, gasification efficiency is significantly improved. As mentioned above, the large upward flow formed in the center prevents the formation of plate-like sinter as described above even if high concentration oxygen is supplied from the nozzle, so it does not interfere with stable gasification movement. It won't happen.

In the gasifying agent lower blowing nozzle of the present invention, as shown in the example of FIG.
It is preferable to design the outer diameter of the part that protrudes horizontally into the fluidized bed formation area beyond the inner wall surface of the fluidized bed to be small in order to avoid adhesion of molten ash to this part. It is preferable to design the inner diameter d' to be as small as possible unless it interferes with the desired injection of the gasifying agent. Further, in order to smoothly insert and withdraw the lower blowing nozzle, the maximum horizontal outer diameter d" of the tip including the nozzle tip opening 1 is equal to the through hole diameter d" of the furnace wall 23.
It is better to design it so that it is slightly smaller as shown by Δd in the figure. Examples of dimensions include Δd of about 0.5 to about 5 mm, preferably about 1 to about 3 mm. Such dimensions can be selected and set as appropriate by those skilled in the art, but for example, in the figure, the nozzle protrusion length a = about 60 to
Approximately 90mm, nozzle base inner diameter d = approximately 20mm to approximately 40m
m, nozzle protrusion inner diameter d' - approx. 15 mm ~ approx. 30 mm
mm (however, d) d', preferably d-d' - about 5
m m - about 15 mm), △d - about 0.5 mm to about 5 mm
, nozzle tip opening diameter d--about 10 mm to about 15 mm,
For example, dimensions such as:

As described above, the gasifier lower blowing nozzle of the present invention is provided in the lower part of the fluidized bed forming area of the coal fluidized bed gasifier.
A lower gasifying agent blowing nozzle is provided horizontally through the furnace wall and protrudes in the direction of the center line of the area, and the tip opening of the nozzle is directed diagonally upward in the direction of the center line of the area. It is characterized by its opening. According to a preferred embodiment, it is provided horizontally in the lower part of the fluidized bed forming area of the distributed plate type coal fluidized bed gasifier, penetrating the furnace wall and protruding in the direction of the center line of the area. A gasifying agent lower stage blowing nozzle, the tip opening of the nozzle opens in the direction of the center line of the area and diagonally upward, and the maximum horizontal direction of the tip includes the tip opening. It is possible to provide a gasifying agent lower blowing nozzle characterized in that the diameter d'' is slightly smaller than the diameter d'' of the through hole in the furnace wall.

FIG. 3 of the accompanying drawings discloses a schematic illustration of various types of coal gasifiers.

(A), (B), (C) and (D) in FIG. 3 are different in the following points.

(A) does not have a gas blowing nozzle; (B)
The gas injection nozzle does not protrude from the inner surface of the furnace wall. (C) The gas injection nozzle projects from the inner surface of the furnace wall in the direction of the center line, and its opening is oriented perpendicular to the center line. (D) Table 1 shows the results obtained by operating each of the above-mentioned units in which the gas blowing nozzle faces toward the center line from the inner surface of the furnace wall and its opening faces diagonally upward (the nozzle of the present invention). ;.

Regarding the above types A, B, C, and D gasifiers,
Furthermore, the following findings were obtained.

In the Type A gas and other agent supply system using only the distribution plate, the upper temperature of the gasifier layer cannot be raised to 900°C or higher because the permissible limit concentration of oxygen from the distribution plate is as low as 13% or less. Good results could not be obtained since the gas efficiency was below 70% (see Table 1).

Although there was a slight difference in continuous operation time between types B and C, which combined use of horizontal blowing nozzles for gases and other agents, cylindrical and plate-shaped sinter that had grown around the horizontal blowing nozzle for gases and other agents accumulated on the dispersion plate. However, the gasifier had to be shut down after a maximum of 190 hours.

By using the Type D 60' upward nozzle for supplying gas and other agents, troubles caused by sintered materials are eliminated.
In addition, by supplying 30% more concentrated oxygen from the same nozzle, it became possible to raise the furnace temperature, and the cold gas efficiency was greatly improved to 75%.

Further, the operation time was also 300 hours and 500 hours, but no problems occurred, and the reliability of the gasifier was improved.

FIG. 4 is a side sectional view of another example of the gasifying agent lower stage nozzle structure of the present invention. The nozzle in FIG. 4 has three nozzle tip openings 2° 2' and 2'' as shown. All of these nozzle tip openings open toward the center line and diagonally upward. are doing.

The nozzle of the present invention also includes a nozzle having a plurality of such nozzle tip openings.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an example of a gasifying agent lower stage nozzle structure for a coal fluidized bed gasifier according to the present invention. FIG. 2 is a partially cutaway implicit sectional view showing one embodiment of a distributed plate type coal fluidized bed gasifier. FIG. 3 is a schematic illustration of various types of coal gasifiers. FIG. 4 is a sectional view of another example of the gasifying agent lower stage nozzle structure of the present invention.

Claims (1)

[Claims] 1. A gasifying agent lower blower provided horizontally in the lower part of the fluidized bed forming area of the coal fluidized bed gasifier, penetrating the furnace wall and protruding in the direction of the center line of the area. A gasifying agent injection nozzle structure for a coal fluidized bed gasifier, characterized in that the nozzle has a tip opening opening in the direction of the center line of the area and diagonally upward. thing. 2. The nozzle structure according to claim 1, wherein the coal fluidized bed gasifier is a porous rectifier (plate) type coal fluidized bed gasifier.