JPH0232528B2 - KANENSEIBIFUNBUTSUNENSHOYOBAANA - Google Patents

Description

[Detailed description of the invention] The present invention provides pulverized coal, fine plastic powder, wood chips,
The present invention relates to an improvement of a burner for burning combustible fine powder such as vegetable fiber fine powder.

Conventionally, this type of burner B for combustion of combustible fine powder has been constructed by fitting an outer tube 1 with a large diameter and an inner tube 2 with a smaller diameter concentrically, as shown in FIG. The joint flange 1a of the inner pipe 2 and the joint flange 2a of the inner pipe 2 are abutted and fixed to form a double pipe structure, and pulverized coal as combustible powder is inserted between the inner surface of the outer pipe 1 and the outer surface of the inner pipe 2. There is one in which the pulverized coal is formed as a supply path 3 through which the pulverized coal flows together with the compressed air, and the inside of the inner tube 2 is formed as an air supply path 4 through which primary air for combustion flows. In addition, in Figure 1,
5 is a pulverized coal inlet for feeding pulverized coal together with pressurized air into the pulverized coal supply path 3; 6 is an air inlet for feeding primary air for combustion into the air supply path 4.

However, in such a conventional burner for combustion of combustible fine powder, the pulverized coal is not supplied to the pulverized coal supply path 3.
Center line l of burner B directly from tip spout 7
Since burner B has a structure in which the flame is ejected in a direction, the shape of the flame of burner B is inevitably limited to a long flame. For this reason, although pulverized coal with a low carbon content can achieve sufficient combustion efficiency, the combustion degree of the same pulverized coal with a high carbon content is low. becomes incomplete,
Combustion efficiency may decrease accordingly. In order to solve this problem, an appropriate number of deflection plates (not shown) are provided in the vicinity of the spout 7 of the pulverized coal supply path 3, and the pulverized coal is removed from the spout 7 by the action of the deflection plates. It is conceivable that the pulverized coal be ejected as a swirling flow to promote the oxidation effect, thereby shortening the flame shape and improving the combustion efficiency of the pulverized coal. However, depending on the type of pulverized coal, the combustion efficiency of pulverized coal changes depending on the oxidation rate, etc., so depending on the burner equipped with a specified deflection plate, it is possible to improve the combustion efficiency of pulverized coal. However, burners B must be individually formed to achieve the desired combustion efficiency depending on the type of pulverized coal, resulting in a lack of versatility.

In addition, since it is necessary to increase the relative velocity of the pulverized coal particles in order to increase the combustion speed of the pulverized coal, the opening area of the tip jet port 7 portion of the pulverized coal supply path 3 must be reduced to a certain extent. That much,
There is a problem in that the clearance d between the inner surface of the outer tube 1 and the outer surface of the inner tube 2 inevitably becomes narrower, making it easier for lumps of pulverized coal to clog the spout 7 portion.

Incidentally, such a problem also occurs with combustible fine powder other than pulverized coal.

The present invention has been made based on the above-mentioned viewpoints, and its purpose is to effectively prevent clogging of combustible fine powder while optimizing combustion according to the type of flammable fine powder. An object of the present invention is to provide a burner for burning combustible fine powder which can maintain a constant state.

The gist of the present invention is to attach the outer tube and the inner tube so that they can move relative to each other, and to attach the The burner for combustion of combustible fine powder is provided with guide protrusions at predetermined angular intervals, and the direction of ejection of the combustible fine powder is variable according to the relative positional relationship of these guide protrusions.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

In the first embodiment shown in FIG. 2, the basic structure of burner B is a double-tube structure in which a large-diameter outer tube 1 and a smaller-diameter inner tube 2 are fitted concentrically. A pulverized coal supply path 3 is formed between the inner surface of the inner tube 1 and the outer surface of the inner tube 2 through which pulverized coal as a combustible fine powder flows together with pressurized air, and an air supply path 3 through which primary air for combustion flows inside the inner tube 2. Road 4
It is formed as follows.

In this embodiment, the base 2b of the inner tube 2
As shown in FIGS. 2 and 3, the base 1 of the outer tube 1 has a larger diameter than other parts.
b It is slidably and rotatably fitted to the inner circumferential surface. Further, a connecting flange 2c is provided on the outer peripheral surface of the base 2b of the inner tube 2, and this connecting flange 2c comes into contact with a connecting flange 1c formed at the base end of the outer tube 1. An elongated bolt insertion hole 1d and a circular bolt insertion hole 2d extending in the circumferential direction are provided at corresponding portions of the connecting flanges 1c and 2c. The outer pipe 1 and the inner pipe 2 each have a connecting flange 1.
Bolts 10 are inserted into the bolt insertion holes 1d and 2d of c and 2c.
are inserted and tightened with nuts 11 to be connected and fixed. In this case, bolt insertion hole 1d
Since the tube has a long hole shape, it is possible to change the relative angular positional relationship between the outer tube 1 and the inner tube 2 within a predetermined range.

Further, as shown in FIGS. 2, 4, and 5, a predetermined angle is formed on the inner circumferential surface of the outer tube 1 and the outer circumferential surface of the inner tube 2 in the vicinity of the spout 7 of the pulverized coal supply path 3. An outer guide protrusion 13 and an inner guide protrusion 14 are provided symmetrically at each interval. These guide protrusions 13 and 14 are made of a heat-resistant material such as nickel or chrome steel, and are formed into a substantially right triangular prism shape with a height slightly smaller than the clearance of the jet nozzle 7 portion. When the outer guide protrusion 13 is attached to the inner circumferential surface of the outer tube 1, the outer guide protrusion 13 forms a straight flow guide surface 13a along the center line direction and radial direction of the burner B, and a straight flow guide surface 13a along the center line direction and radial direction of the burner B. 13a is formed with a swirling flow guide surface 13b that intersects with the swirling flow guide surface 13b at a predetermined angle θ. On the other hand, the inner guide protrusion 14 is also attached to the outer peripheral surface of the inner tube 2 so that a straight flow guide surface 14a and a swirling flow guide surface 14b are formed. is the outer guide protrusion 1
It faces the swirling flow guide surface 13b of No. 3.

Incidentally, in FIG. 2, reference numeral 16 is an operating rod for rotating the inner tube 2, and since the other configurations are the same as those of the prior art, a detailed explanation thereof will be omitted here.

Therefore, according to the combustion burner according to this embodiment, by changing the relative position between the outer tube 1 and the inner tube 2, the relative positional relationship between the outer guide protrusion 13 and the inner guide protrusion 14 can be changed. It becomes possible. Now, if the relative positions of the respective guide protrusions 13 and 14 are represented schematically on a plane, for example, as shown in FIG. When set at a position in contact with the flow guide surface 14b, the jet outlet 7 is defined by the straight flow guide surface 13a of the outer guide protrusion 13 and the straight flow guide surface 14a of the inner guide protrusion 14. Therefore, the pulverized coal is ejected from the ejection port 7 as a straight flow as shown by the arrow _S1 , and the flame shape of the burner B becomes a long flame. From this state, if the inner tube 2 is rotated in a predetermined direction and fixed to the outer tube 1, the inner guide protrusion 14 will be set at an intermediate position between the outer guide protrusions 13, 13, as shown in FIG. 6b. . In this case, the spout 7 has a portion 7a defined by the swirling flow guide surface 13b of the outer guide protrusion 13 and the swirling flow guide surface 14b of the inner guide protrusion 14, and a rectilinear flow guide surface of the outer guide protrusion 13. 13a and a straight flow guide surface 14a of the inner guide protrusion 14. In this state, the pulverized coal is ejected from one ejection port portion 7a in the direction along the swirling flow guide surfaces 13b, 14b, and is ejected from the other ejection port portion 7b as a straight flow. is ejected as a swirling flow in the combined direction of both as shown by arrow _S2 , and the flame shape of burner B becomes shorter than that shown in FIG. 6a. If the inner tube 2 is further rotated to the maximum extent in a predetermined direction from this state and fixed to the outer tube 1, as shown in FIG. It is set at a position in contact with the rectilinear flow guide surface 13a. In this case, the spout 7 is connected to the swirling flow guide surface 13b of the outer guide protrusion 13 and the inner guide protrusion 1.
4, the pulverized coal flows in the direction indicated by the arrow from the spout 7.
The swirling flow is ejected in the direction along the swirling flow guide surfaces 13b and 14b as shown by _S3 , and the flame shape of burner B becomes the shortest flame.

Furthermore, in this embodiment, since the inner tube 2 is movable relative to the outer tube 1 in the direction of the center line l of the burner B, the inner tube 2 is movable relative to the outer guide protrusion 13 as shown in FIG. 6d. It is also possible to set the inner guide protrusion 14 offset in the direction of the center line l of the burner B, and the passage condition of the jet nozzle 7 can be further varied. In this case, the connecting flange 1c of the outer pipe 1 and the connecting flange 2c of the inner pipe 2 are
For example, as shown in FIG.
5 and are connected and fixed with bolts 10 and nuts 11.

Furthermore, in this embodiment, the inner tube 2 is
Since it is movable in the direction of the center line l of the burner B with respect to the outer tube 1, when the inner tube 2 is repeatedly moved forward and backward along the center line l direction of the burner B, as shown in FIG.
As shown in FIG. 2, the swirling flow guide surface 14b of the inner guide protrusion 14 repeatedly abuts against the swirling flow guide surface 13b of the outer guide protrusion 13. Therefore, even if lumps of pulverized coal adhere to the swirling flow guide surface 13b or 14b due to the combustion flame of burner B, the impact force caused by the collision between the guide protrusions 13 and 14 The agglomerates are crushed and removed. Therefore, the situation in which the opening area of the jet nozzle 7 is unnecessarily narrowed due to the adhesion of the lumps can be effectively prevented.

Furthermore, since it is necessary to increase the relative velocity of the pulverized coal particles in order to increase the combustion speed of the pulverized coal, the opening area of the nozzle 7 portion must be reduced to some extent. Since the guide protrusions 13 and 14 are provided, the clearance d' between the inner surface of the outer tube 1 and the outer surface of the inner tube 2 is wider than that of the conventional one d, and the spout 7 portion There is no concern that the lumps of pulverized coal will clog the tank.

In the above embodiment, the outer tube 1 and the inner tube 2 are relatively rotatable, and the center line l of the burner B is
Although the burner B is attached so as to be movable along the direction, it is not necessarily limited to this, and both may simply be attached so that they can rotate relative to each other, or they are movable along the direction of the center line l of the burner B. It may be attached to. Furthermore, the mounting structure between the outer tube 1 and the inner tube 2 is not limited to that shown in the embodiment, and it is also possible to mount them so that they can move relative to each other using a combination of gears or a rack and pinion. do not have. Furthermore, each guide protrusion 13, 14
It goes without saying that the design can be changed as appropriate. For example, if the ejection direction of pulverized coal is to be changed more greatly, as shown in FIG.
It is sufficient to set the angle θ' with b and 14b to be large,
Further, as shown in FIG. 8b, the positions of the guide protrusions 13 and 14 may be set so as to close the spout, and the shape, size, etc. may be limited to those shown in the embodiment. Not done. Furthermore, the present invention is not limited to burners of the type shown in the above embodiments, for example, as shown in FIG.
Various types of burners B are available, such as those with a built-in burner 17 for burning fluid fuel inside the burner B, and those with a secondary air supply pipe 18 for combustion provided outside the outer tube 1.
Of course, it can be applied to The present invention can of course be applied to burners for burning pulverized coal and a wide variety of other combustible fine particles.

As explained above, according to the burner for combustion of combustible fine powder according to the present invention, the outer tube and the inner tube are mounted so as to be relatively movable, and the outer tube Guide protrusions are provided at predetermined angular intervals on the inner circumferential surface of the tube and on the outer circumferential surface of the inner tube, and the ejecting direction of combustible fine powder is changed from a straight flow to a swirling flow according to the relative positional relationship of these guide protrusions. Since it is variable, the shape of the combustion flame can be freely adjusted using a single burner, making it possible to constantly maintain the optimal combustion condition depending on the type of combustible powder, improving the versatility of the burner. can be done. Further, according to the present invention, the clearance between the inner surface of the outer pipe and the outer surface of the inner pipe in the vicinity of the ejection port can be increased compared to the conventional method without increasing the opening area of the ejection port, so that combustible It is possible to effectively prevent clogging of the combustible particulate matter at the ejection port without reducing the combustion speed of the combustible particulate matter.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of a conventional burner for burning combustible fine powder, and FIG. 2 is a cross-sectional view showing an example of a burner for burning combustible fine powder according to the present invention.
Figure 3 is an exploded perspective view of the middle part of Figure 2, and Figure 4 is an exploded perspective view of the middle part of Figure 2.
FIG. 5 is an enlarged partially cutaway perspective view of the middle part of the figure; FIG. 5 is a view taken from the direction of arrow V in FIG. 4; FIGS. Fig. 7 is a cross-sectional explanatory diagram showing an example of the mounting structure between the inner pipe and the outer pipe when the inner pipe moves in the direction of the center line of the burner, and Fig. 8 a and b show the shape and arrangement relationship of the guide protrusions. FIG. 9 is a schematic diagram showing a modification example, and FIG. 9 is a sectional view showing a modification example of the burner for combustion of combustible fine powder according to the present invention. B...burner, 1...outer tube, 2...inner tube,
3...Pulverized coal supply path (combustible fine powder supply path), 4
... Air supply path, 7 ... Jet outlet, 13 ... Outer guide projection (guide projection), 14 ... Inner guide projection (guide projection), 13a, 14a ... Straight flow guide surface, 13b, 14b ... Turning flow guide surface.

Claims (1)

[Claims] 1. An outer tube and an inner tube are fitted concentrically to form a double tube structure, and the space between the inner surface of the outer tube and the outer surface of the inner tube is formed as a combustible fine powder supply path. , in a burner for combustion of combustible fine powder in which the inside of the inner tube is formed as an air supply passage, the outer tube and the inner tube are mounted so as to be relatively movable, and the outer Guide protrusions are provided at predetermined angular intervals on the inner circumferential surface of the tube and on the outer circumferential surface of the inner tube, and the ejecting direction of the combustible fine powder is made variable according to the relative positional relationship of these guide protrusions. A burner for burning flammable fine powder. 2. The burner for combustion of combustible fine powder according to claim 1, wherein the outer tube and the inner tube are attached so as to be able to rotate relative to each other. 3. The burner for combustion of combustible fine powder according to claim 1 or 2, wherein the outer tube and the inner tube are attached to be movable relative to each other in the direction of the center line of the burner. 4. Claims characterized in that the guide protrusion includes a rectilinear flow guide surface along the radial direction and centerline direction of the burner, and a swirl flow guide surface that intersects the rectilinear flow guide surface at a predetermined angle. The burner for combustion of combustible fine powder according to any one of Items 1 to 3. 5. The guide protrusion of the outer tube and the guide protrusion of the inner tube are arranged so that their respective swirling flow guide surfaces face each other. Burna.