JPH08135918A - Pulverized-coal burner - Google Patents

Abstract

PURPOSE: To allow a driving rod and a concentration adjusting ring of a pulverized-coal burner to operate smoothly by providing a four-joint rotation mechanism with parallel opposite sides between a rod of an air cylinder and the driving rod. CONSTITUTION: A bracket 15 is provided at the rear end of a burner exterior cylinder 8. A link 31 to be connected to the upper ends of links 26 and 30 is rotatably provided on the bracket 15 at the lengthwise center of the link 31 with a pin 37 and a lower link 32 is rotatably supported on the front lower end of the bracket 15 at the lengthwise center with a pin 40. The links 26 and 30 and the upper and lower links 31 and 32 are parallel with each other and form a four-joint rotation mechanism 33. The four-joint rotation mechanism 33 is arranged so that the link 30 is oriented in the horizontal direction that perpendicularly intersects the axial line of a driving rod 18. The link 30 can move with back and forth motions of a rod 16a of an air cylinder 16 as it stays in a horizontal posture that perpendicularly intersects the driving rod 18.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a pulverized coal burner.

[0002]

2. Description of the Related Art Pulverized coal combustion, in which pulverized coal pulverized by a mill is mixed with primary air to be supplied to a pulverized coal burner and jetted from the pulverized coal burner to perform floating combustion, is a coal which has been widely and commonly used. 6 to 8 is an example of the pulverized coal burner used in the combustion furnace of FIG.
Shown in In the figure, 1 is a furnace, 2 is a throat formed at a predetermined position on the side wall of the furnace 1, and 3 is outside the furnace 1 near the throat 2 for supplying secondary air 4 for combustion to the furnace 1. The pulverized coal burner 5 is a wind box arranged so as to pass through the wind box 3 and is arranged at the center of the throat 2.

The pulverized coal burner 5 is disposed in the center of the pulverized coal burner 5 and has a substantially cylindrical shape, and a burner inner cylinder 6 having a narrowed portion at the tip opening portion whose diameter decreases sharply toward the tip. An oil burner 7 inserted in the axial center position of the burner inner cylinder 6 and concentrically arranged on the outer periphery of the burner inner cylinder 6, with a rear end portion having a substantially cylindrical shape and an intermediate portion directed toward the tip. A hollow cone-shaped burner outer cylinder 8 having a gradually decreasing diameter, a burner nozzle 9 having a diameter sharply decreasing toward the tip at the tip opening of the burner outer cylinder 8, and a pulverized coal 10 and a primary coal powder at a tip position inside the burner nozzle 9. The burner outer cylinder 8 is provided with a separation cylinder 12 for changing the concentration with the air 11, and the pulverized coal 10 formed in the tangential direction at the rear end portion of the burner outer cylinder 8 and supplied together with the primary air 11 from a mill (not shown). Pulverized coal inlet leading into the burner outer cylinder 8 13 is formed.

A density adjusting ring 14 is movably fitted on the burner inner cylinder 6 and is provided above the rear end of the burner outer cylinder 8 for moving the density adjusting ring 14. Air cylinder 16 on the bracket 15
Is provided, and the proximal end portion of the fitting / removing metal fitting 17 whose middle portion in the longitudinal direction is supported by the tip portion of the bracket 15 is connected to the tip of the rod 16a of the air cylinder 16.
The tip of the drive rod 18 is connected to the rear end of the drive rod 18 whose tip is connected to the concentration adjusting ring 14. The drive rod 18 is, as shown in FIGS. 7 and 8, the burner inner cylinder 6
It is fitted in a semicircular groove 19 provided in the longitudinal direction of the burner inner cylinder 6 at symmetrical positions on both sides, and extends along the groove 19.

Further, in order to adjust the air amount of the secondary air 4, an air register 20 is arranged in a space formed between the throat 2 and the wind box 3 so as to surround the throat 2 in a circular shape. In order to separate the secondary air 4 into the inner side and the outer side, a plurality of inner vanes 21 are arranged in the inner circumferential direction of the air register 20, and in order to guide the tertiary air 22 to the burner inner cylinder 6. Further, the wind box 3 and the rear end of the burner inner cylinder 6 are communicated with each other by a tertiary air pipe 23.

At the time of high load of a mill (not shown), the air cylinder 16 is actuated in the direction in which the rod 16a contracts, and the concentration adjusting ring 1 is inserted through the insertion / removal fitting 17 and the drive rod 18.
4 is moved to the rear end side of the burner inner cylinder 6 (the position indicated by the chain double-dashed line in FIG. 6). Pulverized coal 1 supplied from the pulverized coal inlet 13 into the burner outer cylinder 8 together with the primary air 11.
0 flows around the rear end portion of the burner outer cylinder 8 to be equalized in the circumferential direction, then flows to the tip end side of the burner outer cylinder 8, and gets over the concentration adjusting ring 14. At that time, the concentration adjusting ring 14 is guided to the outside of the inside of the burner outer cylinder 8 along the outer peripheral surface of the concentration adjusting ring 14, but the concentration adjusting ring 14 is located on the rear end side having a large diameter of the conical burner outer cylinder 8. Therefore, the distance between the inner surface of the burner outer cylinder 8 and the outer periphery of the concentration adjusting ring 14 is kept relatively wide, and the tip of the burner outer cylinder 8 and the concentration adjusting ring 1 are kept.
4, the primary air 11 and the pulverized coal 10 pass through the portion where the concentration adjusting ring 14 is located, and then diffuse again into the entire inside of the burner outer cylinder 8 to generate fine powder in the primary air 11. Separation cylinder 1 with charcoal 10 evenly distributed
2 is ejected from the tip of the burner outer cylinder 8 through both inner and outer sides of the burner 2, and is mainly mixed with the secondary air 4 supplied from the wind box 3 and burned.

Further, when the load of the mill is low, the air cylinder 16 is operated in the direction in which the rod 16a extends, and the concentration adjusting ring 14 is moved through the insertion / removal fitting 17 and the drive rod 18 to the tip side of the burner inner cylinder 6 (see FIG. 6). (Position indicated by solid line inside)
Move to. The pulverized coal 10 supplied from the pulverized coal inlet 13 to the inside of the burner outer cylinder 8 together with the primary air 11 circulates at the rear end of the burner outer cylinder 8 and is equalized in the circumferential direction, and then the burner outer cylinder 8 is crushed. It flows to the tip side and gets over the concentration adjusting ring 14. At that time, it is guided to the outside of the inside of the burner outer cylinder 8 along the outer peripheral surface of the concentration adjusting ring 14,
The concentration adjusting ring 14 is located on the tip side of the cone-shaped burner outer cylinder 8 having a small diameter, and the distance between the inner surface of the burner outer cylinder 8 and the outer periphery of the concentration adjusting ring 14 is relatively narrow and the outside of the burner is large. Since the distance between the tip of the cylinder 8 and the concentration adjusting ring 14 is short, the flow velocity of the primary air 11 and the pulverized coal 10 is increased, and immediately after the primary air 11 passes through the portion where the concentration adjusting ring 14 is located, the primary air 11 is again discharged into the burner outer cylinder 8 The pulverized coal 10, which has a larger specific gravity than air, flows along the outer peripheral side of the burner outer cylinder 8 as it is due to inertial force, and is partially concentrated in the primary air 11, Most of the air passes through the outside of the separation cylinder 12 and the primary air 11 passes through both the inside and outside of the separation cylinder 12 and is ejected from the tip of the burner outer cylinder 8 to be mixed mainly with the secondary air 4 supplied from the wind box 3. Burning stably To.

[0008]

However, in the above-mentioned pulverized coal nozzle, the intermediate portion in the longitudinal direction is supported by the bracket 15 in order to move the concentration adjusting ring 14 fitted on the burner inner cylinder 6. The front end of the rod 16a of the air cylinder 16 and the rear end of the drive rod 18 connected to the concentration adjusting ring 14 are connected via a lever-shaped metal fitting 17 but move in the direction along the axis. The rod 16a of the air cylinder 16 and the drive rod 18 are connected to both ends of the insertion / removal metal fitting 17 that rotates about the intermediate portion as a fulcrum.
A component force in a direction orthogonal to each axis acts on the eight. Therefore, smooth operation is hindered, and there is a problem that the drive rod 18 fitted in the semicircular groove 19 provided in the burner inner cylinder 6 does not move smoothly.

In view of the above situation, the present invention can smoothly operate the drive rod and the concentration adjusting ring by providing a four-bar rotation mechanism having opposite sides parallel to each other between the rod of the air cylinder and the drive rod. The purpose is to provide a pulverized coal burner.

[0010]

According to a first aspect of the present invention, there is provided a burner inner cylinder having a substantially cylindrical shape and a groove extending in the longitudinal direction on the outer periphery, and a concentric outer periphery of the burner inner cylinder. A burner outer cylinder that forms a pulverized coal passage between the burner inner cylinder and the burner inner cylinder, a concentration adjustment ring that is fitted onto the burner inner cylinder and is movable by being guided by the groove, and the concentration adjustment ring. In a pulverized coal burner including a drive rod connected to the outside of the rear end of the burner outer cylinder along the groove and a fluid pressure cylinder having a rod capable of expanding and contracting in a direction parallel to the drive rod, opposite sides are parallel to each other. A long hole extending in the longitudinal direction is provided substantially at the center in the longitudinal direction of each link on one side of the four-node rotating mechanism, and the link provided with the long hole is orthogonal to the rod of the fluid pressure cylinder and the drive rod. When a four-bar rotation mechanism is installed to extend to , The long hole of one of the links on the pair of sides is movably engaged with the rod tip of the fluid pressure cylinder, and the long hole of the other link is movable to the rear end of the drive rod. And rotatably support the substantially central portion in the longitudinal direction of each link on the opposite side of the other side of the four-bar rotation mechanism so that each link on the side of the pair of sides is fluidized as the rod of the fluid pressure cylinder expands and contracts. It is formed so as to be movable while maintaining the state orthogonal to the rod and the drive rod of the pressure cylinder.

A second aspect of the present invention is a burner inner cylinder having a substantially cylindrical shape and having a groove extending in the longitudinal direction on the outer periphery, and a burner concentrically arranged on the outer periphery of the burner inner cylinder. A burner outer cylinder that forms a pulverized coal passage with the inner cylinder, a concentration adjustment ring that is fitted onto the burner inner cylinder and is movable by being guided by the groove, and the groove connected to the concentration adjustment ring. In a pulverized coal burner including a drive rod extending to the outside of the rear end of the burner outer cylinder along a line and a fluid pressure cylinder having a rod capable of expanding and contracting in a direction parallel to the drive rod, a four-sided node having opposite sides parallel to each other. An elongated hole extending in the longitudinal direction is provided substantially at the center in the longitudinal direction of each link on one side of the rotating mechanism.
A four-bar rotation mechanism is arranged so that the link provided with the elongated hole extends in a direction orthogonal to the rod and the drive rod of the fluid pressure cylinder, and the elongated hole of one of the links on the side of the pair of sides. Is movably engaged with the rod tip of the fluid pressure cylinder in a direction orthogonal to the rod, and the elongated hole of the other link is movably engaged with the rear end of the drive rod. At least one of the links on the opposite side of the other side of the mechanism is rotatably supported at a substantially central portion in the longitudinal direction, and as the rod of the fluid pressure cylinder expands and contracts, the links on the pair of sides are driven and driven by the rod of the fluid pressure cylinder. It is formed so that it can move while maintaining a state orthogonal to the rod.

[0012]

Therefore, according to the first aspect of the invention, when the rod of the fluid pressure cylinder is expanded and contracted, the other opposite side connected to both ends of the one link on one side engaged with the tip of the rod. Each of the links rotates about the respective support points at the center thereof while maintaining a parallel state to each other, is connected to the other end of each link on the other side and is engaged with the rear end of the drive rod. Since the other link on the side of the pair moves while maintaining a state of being orthogonal to the drive rod, almost no component force acts on the drive rod in the direction orthogonal to its axis.

According to the second aspect of the invention, when the rod of the fluid pressure cylinder is expanded and contracted, one of the links on the pair of sides engaged with the tip of the rod is orthogonal to the rod with respect to the tip of the rod. The link on one side of the other opposite side connected to one end of the one link rotates about the supporting point at the center of the other link on the other side of the other side. Is displaced in parallel with the one link, and is connected to the other end of each link on the other opposite side and the other link on the one side engaged with the rear end of the drive rod is orthogonal to the drive rod Since it moves while maintaining the above, almost no component force acts on the drive rod in the direction orthogonal to its axis.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the outline of an embodiment of the pulverized coal burner of the first invention, FIG. 2 is a perspective view showing the II portion of FIG. 1, and FIG. 3 is a view taken along the line III-III of FIG. Is. In the figure,
The same parts as those in FIGS. 6 to 8 are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, at the tip of the rod 16a of the air cylinder 16, there are provided pins 24 projecting to the left and right in the horizontal direction orthogonal to the axis of the rod 16a, and an elongated hole 25 extending in the longitudinal direction is provided at the center. A pair of links 26 having a predetermined length are provided, and the long holes 25 of the links 26 are externally fitted and engaged with the pins 24 of the rod 16a of the air cylinder 16.

Further, at the rear end of the drive rod 18 connected to the concentration adjusting ring 14, a predetermined space is provided on the left and right in the horizontal direction, the two parallel to each other and extend toward the side opposite to the inner cylinder 6 of the burner, and both ends are outside. A fork-shaped connecting fitting 28 having a pin 27 protruding to the inside is provided, and a pair of links 30 having a long hole 29 extending in the longitudinal direction in the central portion and having substantially the same length as the link 26 are provided. The long hole 29 is externally fitted and engaged with the pin 27 of the connecting fitting 28.

Further, a pair of upper links 31 for connecting the upper ends of the links 26, 30 to the front end of the bracket 15 provided at the rear end of the burner outer cylinder 8 is provided with a substantially central portion in the longitudinal direction thereof. At the lower end of the bracket 15, the lower ends of the links 26 and 30 are rotatably supported by pins 37 and 38, respectively.
A lower link 32, which is connected via 9 and has a length substantially the same as that of the upper link 31, is rotatably supported by a pin 40 at a substantially central portion in the longitudinal direction thereof, and upper ends of the links 26 and 30 are respectively supported. The upper links 31 are connected via the pins 41 and 42, and the links 26 and 3 are connected.
0, the upper link 31 and the lower link 32 form a four-bar rotation mechanism 33 of a predetermined size whose opposite sides are parallel to each other, and the four-bar rotation is performed so that the link 30 is oriented in the vertical direction orthogonal to the axis of the drive rod 18. A mechanism 33 is arranged so that the link 30 can move while maintaining the state orthogonal to the drive rod 18 as the rod 16a of the air cylinder 16 expands and contracts.

Next, the operation will be described. For example, when the air cylinder 16 is operated in the direction in which the rod 16a contracts, the acting force in the contraction direction of the air cylinder 16 is applied to the link 26 engaged with the rod 16a via the pin 24 provided at the tip of the rod 16a. The upper link 31 and the lower link 32, which act as an external force in the contracting direction of the rod 16a and are connected to both ends of the link 26 by the external force, maintain a state in which they are parallel to each other around their respective support points. While rotating in the clockwise direction, the link 26 is
5 slides upward along the circumferential surface of the pin 24 at the tip of the rod 16a, and relatively moves obliquely upward.

Further, the link 3 is connected to the other ends of the upper link 31 and the lower link 32 and is engaged with the drive rod 18 via a connecting fitting 28 provided at the rear end of the drive rod 18.
0 means that the long hole 29 slides downward along the peripheral surface of the pin 27 of the connecting fitting 28 while the upper link 31 and the lower link 32 are rotated, and the slanted hole 29 moves relatively obliquely downward. To do.

Along with the parallel movement of the link 30, the drive rod 18 connected to the link 30 via a connecting fitting 28.
The concentration adjustment ring 14 (see FIG. 6) connected to the burner inner cylinder 6 moves to the rear end side of the inner burner cylinder 6 along the inner burner cylinder 6.

On the other hand, if the air cylinder 16 is operated in the direction in which the rod 16a extends, the links 26, 30, 31, 32 forming the four-bar rotation mechanism 33 operate in the direction opposite to the above-mentioned operation, The concentration adjusting ring 14 is the burner inner cylinder 6
The burner inner cylinder 6 is moved to the front end side along.

According to the above description, the rod 16a of the air cylinder 16 and the drive rod 18 are connected by the four-bar rotation mechanism 33, so that the connecting fitting 2 is attached to the rear end of the drive rod 18.
Since the link 30 engaged via 8 is formed so that it can be translated in the direction orthogonal to the axis of the drive rod 18, the link 30 can be moved in the direction orthogonal to the axis of the drive rod 18 with respect to the drive rod 18. Since almost no component force acts, the drive rod 18 operates smoothly and the operation of the concentration adjusting ring 14 can be always maintained smoothly.

FIG. 4 is a sectional view showing the outline of an embodiment of the pulverized coal burner of the second invention, and FIG. 5 is a view taken along the line VV of FIG. In the figure, the same parts as those in FIG. 1 to FIG.

In this embodiment, sliders 34 each having a square prism shape of a predetermined size extending in the vertical direction orthogonal to the axis of the rod 16a are provided on both sides of the tip end of the rod 16a of the air cylinder 16 in the horizontal direction, and the central portion thereof is provided. Slot 2 extending in the longitudinal direction
5 is provided with a pair of links 26 having a predetermined length, and the long holes 25 of the links 26 are connected to the rod 16 of the air cylinder 16.
The slider 34 of a is externally fitted and engaged.

Further, at the rear end of the drive rod 18 connected to the concentration adjusting ring 14, a predetermined space is provided on the left and right in the horizontal direction, and the two parallel to each other extend toward the side of the inner cylinder 6 of the burner and both ends are outside. A fork-shaped connecting fitting 28 having a pin 27 protruding to the inside is provided, and a pair of links 30 having a long hole 29 extending in the longitudinal direction in the central portion and having substantially the same length as the link 26 are provided. The long hole 29 is externally fitted and engaged with the pin 27 of the connecting fitting 28.

Further, a pair of upper links 31 for connecting the upper ends of the links 26, 30 to each other via pins 41, 42 are provided at the tip of the bracket 15 provided at the rear end of the burner outer cylinder 8. , Each of the links 2 is rotatably supported by a pin 37 at a substantially central portion in the longitudinal direction thereof.
Lower links 35 having the same length as the upper link 31 are provided by connecting the lower ends of 6 and 30 via pins 38 and 39, respectively, and the lower links 35 are provided by the links 26 and 30, the upper link 31 and the lower link 35. The four-node rotating mechanism 36 having a predetermined size whose opposite sides are parallel to each other is formed, and the four-node rotating mechanism 36 is arranged so that the link 30 faces in the vertical direction orthogonal to the axis of the drive rod 18, and The link 30 is formed so that it can move while maintaining the state orthogonal to the drive rod 18 as the rod 16a expands and contracts.

Next, the operation will be described. For example, when the air cylinder 16 is operated in the direction in which the rod 16a contracts, the acting force in the contraction direction of the air cylinder 16 is applied to the rod 16 via the slider 34 provided at the tip of the rod 16a.
The link 26 engaged with a acts as an external force in the contraction direction of the rod 16a, and the external force causes the upper link 31 connected to the upper end of the link 26 to rotate clockwise around its support point. The link 26 has a long hole 25.
Slides upward along the side surface of the slider 34 at the tip of the rod 16a, and relatively moves obliquely upward.

Further, the link 3 which is connected to the other ends of the upper link 31 and the lower link 35 and which is engaged with the drive rod 18 via a connecting fitting 28 provided at the rear end of the drive rod 18.
0 means that the long hole 29 slides downward along the peripheral surface of the pin 27 of the connecting metal fitting 28 while the upper link 31 and the lower link 35 rotate, and relatively moves obliquely downward. To do.

Along with the parallel movement of the link 30, the drive rod 18 connected to the link 30 via a connecting fitting 28.
The concentration adjustment ring 14 (see FIG. 6) connected to the burner inner cylinder 6 moves to the rear end side of the inner burner cylinder 6 along the inner burner cylinder 6.

On the other hand, when the air cylinder 16 is operated in the direction in which the rod 16a extends, the links 26, 30, 31, 35 forming the four-bar rotation mechanism 36 operate in the direction opposite to the above-mentioned operation, The concentration adjusting ring 14 is the burner inner cylinder 6
The burner inner cylinder 6 is moved to the front end side along.

According to the above, the rod 16a of the air cylinder 16 and the drive rod 18 are connected by the four-bar rotation mechanism 36, so that the connecting fitting 2 is attached to the rear end of the drive rod 18.
Since the link 30 engaged via 8 is formed so that it can be translated in the direction orthogonal to the axis of the drive rod 18, the link 30 can be moved in the direction orthogonal to the axis of the drive rod 18 with respect to the drive rod 18. Since almost no component force acts, the drive rod 18 operates smoothly and the operation of the concentration adjusting ring 14 can be always maintained smoothly.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0034]

According to the pulverized coal burner of the present invention, the rod of the fluid pressure cylinder and the drive rod are connected by a four-bar rotation mechanism, and the link engaging the rear end of the drive rod is connected to the drive rod. Since it is formed so that it can be translated in the direction orthogonal to the axis, almost no component force acts on the drive rod in the direction orthogonal to the axis of the drive rod, so that the drive rod operates smoothly. An excellent effect that the operation of the concentration adjusting ring can be always maintained smoothly can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing an embodiment of a pulverized coal burner of the first invention.

FIG. 2 is a perspective view showing a portion II of FIG.

FIG. 3 is a view taken in the direction of arrows III-III in FIG. 1;

FIG. 4 is a sectional view schematically showing an embodiment of a pulverized coal burner of the second invention.

5 is a view taken along the line VV of FIG.

FIG. 6 is a cross-sectional view schematically showing an example of a conventional pulverized coal burner.

FIG. 7 is a view on arrow VII-VII in FIG.

FIG. 8 is a view on arrow VIII-VIII in FIG.

[Explanation of symbols]

 6 Burner Inner Cylinder 8 Burner Outer Cylinder 14 Concentration Adjustment Ring 16 Air Cylinder (Fluid Pressure Cylinder) 16a Rod 18 Drive Rod 19 Groove 25 Long Hole 26 Link (One Side Side Link) 29 Long Hole 30 Link (One Side Side Link) 31 Upper link (other opposite side link) 32 Lower link (other opposite side link) 33 Four-bar rotation mechanism 35 Lower link (other opposite side link) 36 Four-bar rotation mechanism

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Keiji Makino 3-2-16 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Co., Ltd. Toyosu General Office

Claims (2)

[Claims] 1. A burner inner cylinder having a substantially cylindrical shape and having a groove extending in the longitudinal direction on the outer periphery, which is disposed in the central portion, and a burner inner cylinder concentrically disposed on the outer periphery of the burner inner cylinder. A burner outer cylinder forming a pulverized coal passage, a concentration adjusting ring fitted onto the burner inner cylinder and movable by being guided by the groove, and a burner outer cylinder connected to the concentration adjusting ring along the groove. In a pulverized coal burner equipped with a drive rod extending to the outside of the rear end and a fluid pressure cylinder having a rod capable of expanding and contracting in a direction parallel to the drive rod, one side of a four-node rotating mechanism whose opposite sides are parallel to each other. A long hole extending in the longitudinal direction is provided substantially in the center of each link in the longitudinal direction, and a four-bar rotation mechanism is arranged so that the link provided with the long hole extends in a direction orthogonal to the rod of the fluid pressure cylinder and the drive rod. In addition, The long hole of one of the links is movably engaged with the tip of the rod of the fluid pressure cylinder, and the long hole of the other link is movably engaged with the rear end of the drive rod. Each of the links on the opposite side is rotatably supported at a substantially central portion in the longitudinal direction, and as the rod of the fluid pressure cylinder expands and contracts, the links on the pair of sides are orthogonal to the rod and the drive rod of the fluid pressure cylinder. A pulverized coal burner characterized by being formed so as to be movable while maintaining the state. 2. A burner inner cylinder, which is disposed in the central portion and has a substantially cylindrical shape and has a groove extending in the longitudinal direction on the outer circumference, and a burner inner cylinder which is concentrically disposed on the outer circumference of the burner inner cylinder. A burner outer cylinder forming a pulverized coal passage, a concentration adjusting ring which is fitted onto the burner inner cylinder and is movable by being guided by the groove, and a burner outer cylinder connected to the concentration adjusting ring along the groove. In a pulverized coal burner including a drive rod extending to the outside of the rear end of a cylinder and a fluid pressure cylinder having a rod that can expand and contract in a direction parallel to the drive rod, a pair of sides of a four-node rotating mechanism whose opposite sides are parallel to each other. A long hole extending in the longitudinal direction is provided substantially in the center in the longitudinal direction of each side link, and a four-bar rotation mechanism is provided so that the link provided with the long hole extends in the direction orthogonal to the rod of the fluid pressure cylinder and the drive rod. With the placement
The elongated hole of one of the links on the side of the pair is engaged with the rod tip of the fluid pressure cylinder so as to be movable in a direction orthogonal to the rod, and the elongated hole of the other link is formed in the rod of the drive rod. The rear end portion is movably engaged, and at least one of the other opposite-side links of the four-bar rotation mechanism is rotatably supported at a substantially central portion in the longitudinal direction. As the rod of the fluid pressure cylinder expands and contracts. A pulverized coal burner characterized in that each link on the side of the pair of sides is formed so as to be movable while maintaining a state orthogonal to the rod and the drive rod of the fluid pressure cylinder.