JP2009079804A - Grate block for waste incinerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the crack and melting loss of a front wall portion, and crack and welding due to molten metal. <P>SOLUTION: A guide passage 17 is formed on the bottom of a bock body 12 for guiding combustion air from the rear part to the front part, and a nozzle port 20 is formed at the front end of the guide passage 17 passing through the block body 12 and opening to a combustion plane to inject the combustion air upward, On the rear side of the nozzle port 20 of the guide passage 17, a partition portion 21a is protruded to form an introduction passage 18 to the nozzle port 20 between an inclined inner face 13c of the front wall portion 13 and itself. The combustion air to be guided to the guide passage 17 is bypassed downward by the partition portion 21a and then introduced into the introduction passage 18. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a grate block installed on the hearth of a stoker-type waste incinerator.

On the hearth of the stoker-type incinerator, fixed grate rows and movable grate rows are alternately arranged in the front-rear direction, and the movable grate rows are reciprocated back and forth to recycle the waste in the rear of the combustion chamber. Some of them are sent from the drying section through the combustion section to the front rear combustion section. In such a hearth part, after the combustion air supplied from the lower wind box is received by the grate block and the grate block is cooled, from the nozzle opening formed in the front wall part of the grate block, Patent Documents 1 to 3 propose jetting to the front or below the wall.
Japanese Patent Laid-Open No. 11-6613 Japanese Patent No. 3017861 Japanese Patent No. 3601889

  However, as in Patent Documents 1 to 3, when combustion air is sent forward or downward from the front wall portion, the waste is locally burned intensely immediately before the front wall portion. Due to this local combustion, the front wall of the grate block is exposed to high heat and cracks are generated, and further, combustion air is ejected from the cracks and further waste is burned, resulting in melting of the front wall. To do. Also, the metal contained in the waste is melted, and this molten metal flows into the sliding portion between the bottom surface of the front wall portion and the top surface of the grate block adjacent to the front and is welded. There was a problem that cracking occurred due to heat shock.

  An object of the present invention is to provide a grate block for a waste incinerator capable of solving the above-mentioned problems and preventing cracks and melting damage of the front wall portion of the grate block, cracking due to molten metal, and welding. And

  The invention according to claim 1 is a grate block installed in the hearth part, and projects a rear wall part at the rear part in the waste feed direction on the bottom surface of the block main body and projects the front wall at the front part. And a plurality of recesses in the front-rear direction between the front wall portion and the rear wall portion on the bottom surface of the block body, and guide the combustion air from the rear to the front. And a nozzle port is formed through the block body at the front end portion of the guide passage and jets combustion air upward from the top surface, and a nozzle is provided between the front wall portion on the rear side of the nozzle port of the guide passage. A partition portion that forms an introduction passage to the mouth is provided, and the partition portion is configured to guide the combustion air guided forward along the guide passage downward, and then to the introduction passage. is there.

  According to a second aspect of the present invention, in the configuration of the first aspect, the introduction passage is inclined so that the combustion air ejected from the nozzle port is inclined upward in the front portion with respect to the top surface of the block body. is there.

  According to a third aspect of the present invention, in the configuration of the first or second aspect, the grate block includes a fixed grate array alternately arranged in the front-rear direction on the hearth and a movable fire that is reciprocally movable in the front-rear direction. It is installed in each of the grid rows, and the nozzle ports are formed in a slit shape along the front-rear direction.

  According to the first aspect of the present invention, the front wall portion of the grate block is formed from the portion that is locally burned by the combustion air by providing the nozzle port for injecting the combustion air upward on the front top surface of the block body. And the front wall part of the adjacent grate block arrange | positioned adjacent to a rear side can be spaced apart, a front wall part is no longer exposed to the high heat by local combustion, and an overheating can be prevented. Further, the combustion air guided forward from the guide passage is caused to collide with the partition portion to be detoured downward, and further, the combustion air is caused to collide with the inner surface of the front wall portion to be introduced into the introduction passage, and further to the inner surface of the front wall portion. Therefore, the block main body and the front wall can be effectively cooled by increasing the contact area and the contact time between the combustion air and the partition wall and the inner surface of the front wall. Thereby, the crack of the front wall part of a grate block, a melting loss, the crack by a molten metal, and the welding of a sliding contact part can be prevented.

  According to the second aspect of the invention, the combustion air is jetted upward from the nozzle opening to shift the local combustion site forward and further away from the front wall portion of the adjacent grate block. Overheating of the wall portion can be prevented more effectively. Moreover, durability can be improved by inclining the inner surface of the front wall part which forms an introduction channel | path, and forming the lower part of a front wall part thickly.

  According to the invention described in claim 3, by forming the nozzle port in a slit shape along the front-rear direction, it is possible to prevent the intrusion of waste, and to the nozzle port by the reciprocating motion of the grate block of the movable grate array. The invading waste can be effectively dropped, and clogging of the nozzle opening can be prevented.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
As shown in FIG. 6, the grate block 11 of the waste incinerator according to the present invention is installed in the hearth part 1 of the stoker type incinerator, and is not shown in the combustion chamber 2 of the incinerator. From the waste input at the end to the ash discharge at the front end, a drying section, a combustion section, and a post-combustion section are formed on the hearth section 1, and combustion air is sent from the wind box disposed below to the hearth section 1 It is comprised so that it may supply to the combustion chamber 2 via.

  In the hearth part 1, a fixed grate row 3 in which a plurality of grate blocks 11 are arranged in the width direction and a movable grate row 4 in which a plurality of grate blocks 11 are arranged in the width direction are alternately arranged in the front-rear direction. It is provided that the grate block 11 of the movable grate array 4 is reciprocated at a predetermined stroke L (FIG. 5) by the feed driving device 5 so that the waste is sequentially conveyed from the drying unit to the combustion unit and the post-combustion unit. It is configured.

The grate block 11 according to the present invention is, for example, installed in the drying unit excluding the post-combustion unit and the fixed grate row 3 and the movable grate row 4 of the combustion unit.
That is, as shown in FIGS. 1 to 4, the grate block 11 includes an adjacent grate block 11 disposed adjacent to the rear side, a block main body 12 having a rectangular shape in plan view for supporting waste from below, and a block main body. The front wall portion 13 is suspended downward from the front end portion of the block 12 over the entire width, the rear wall portion 14 is suspended downward from the rear portion side of the block body 12 over the entire width, and is projected rearward from the rear wall portion 14. The bracket part 15 which forms the fitting space 15a of the support shaft 22 (or drive shaft) is comprised.

  The front wall portion 13 has a front surface portion 13b that hangs downward from a front end of the top surface of the block main body 12 through a chamfered portion 13a, and an inclined inner surface 13c that is inclined upward at the rear portion by an inclination angle (same as a jet angle described later) θ. The thickness T of the lower end portion in the front-rear direction is about 3 to 4 times the thickness t of the block main body 12, and the lower end side is formed in a thicker shape, thereby increasing durability. Further, an engagement groove 13d having an inverted trapezoidal cross section (a dovetail groove shape) is formed on the lower end surface of the front wall portion 13 over the entire width direction, and a slide piece 19 is detachably attached to the engagement groove 13d.

  The rear wall portion 14 is formed to have substantially the same length as the front wall portion 13 and is formed longer than the bracket portion 15 and protrudes downward. A plurality of screw holes 14a for mounting the mounting plate 23 through the screws 23a are formed in the lower end surface, and the support shaft 22 (or drive shaft) fitted in the fitting space 15a is prevented from being detached by the mounting plate 23. .

  At the rear of the top surface of the block body 12, a front sliding surface 12a is formed in which the slide piece 19 of the adjacent grate block 11 arranged adjacent to the rear side is slidably contacted within the range of the stroke L (FIG. 5). A combustion surface 12b that is formed below the sliding surface 12a and burns waste is formed in the front portion of the top surface, and the sliding surface 12a and the combustion surface 12b are connected by an inclined surface 12c.

  A pair of left and right outer vertical ribs 16A along the left and right side surfaces protrudes downward between the front wall portion 13 and the rear wall portion 14 on the bottom surface of the block body 12, and between the outer vertical ribs 16A, the outer vertical ribs Three inner longitudinal ribs 16B parallel to 16A project downward and are integrally formed. The four recesses formed between the outer and inner vertical ribs 16A and 16B are formed in a guide passage 17 that guides the combustion air blown from the wind box forward from the rear.

  At the front end of each guide passage 17, a nozzle port 20 that penetrates the block body 12 and opens to the combustion surface 12 b is formed. In addition, a partition portion 21 a that partitions a part of the guide passage 17 and forms an introduction passage 18 to the nozzle port 20 is provided at the lower portion of the nozzle port 20. This partition portion 21a is formed by a partition member 21 having an L-shaped cross section in which a substrate portion 21c is attached to a thick portion 12d of the block body 12 via a mounting bolt 21b. The partition part 21a may be formed integrally with the block body 12 by casting.

  The partition portion 21a is formed in a plate shape, and the inner surface thereof is inclined at an inclination angle θ parallel to the inclined inner surface 13c of the opposed front wall portion 13, and the inner surface of the partition portion 21a and the introduction passage 18 are inclined to the inclined inner surface 13c. Thus, the introduction passage 18 is inclined upward in the front part. Thereby, the combustion air ejected from the nozzle port 20 can be inclined at the ejection angle θ upward in the front part.

  Here, by giving the combustion air from the nozzle port 20 an ejection angle θ, the local combustion site of the waste on the combustion surface 12b is shifted forward, and the local combustion site is moved to the front end of the sliding surface 12a. It is separated from the front wall part 13 of the adjacent grate block 11 to be moved so that the front wall part 13 is not exposed to high heat due to local combustion. In the drawing, the ejection angle θ of the combustion air is shown as 10 °, but this ejection angle θ is preferably in the range of 5 ° or more and 30 °, and if the ejection angle θ is less than 5 °, the front of the local combustion section This is because the amount of displacement is small, and when the ejection angle θ exceeds 30 °, the front wall 13 becomes too thick at the lower end and the weight increases excessively.

  Then, the combustion air guided forward from the rear portion along the guide passage 17 is caused to collide by the partition portion 21a, and once bypassed and cooled, it is further caused to collide with the inclined inner surface 13c of the front wall portion 13 to be introduced into the introduction passage. 18, the block main body 12 is cooled via the partition portion 21 a, and the contact area and the contact time between the combustion air and the inclined inner surface 13 c are sufficiently ensured to make the front wall portion 13 more effective. It is configured to cool down.

  The nozzle port 20 is formed in a slit shape that is long in the front-rear direction corresponding to the moving direction of the movable grate array 4. This is to prevent the intrusion of the waste and to drop the waste that has entered due to the reciprocating movement of the movable grate array 4 in a short time to prevent clogging of the waste.

  In the above configuration, as shown in FIG. 5, the combustion air a from the wind box is blown to the bottom surface of the hearth part 1, and is inclined upward in the front part by the fixed grate row 3 and the movable grate row 4, respectively. The grate block 11 is received at the rear bottom of the grate block 11. The combustion air a is guided forward along the guide passage 17 to cool the block body 12 from the bottom surface side. Further, after the combustion air a collides with the partition portion 21a and is detoured downward, it collides with the inclined inner surface 13c of the front wall portion 13 and is introduced into the introduction passage 18. At this time, the combustion air a is separated into the partition portion 21a. And the contact area and the contact time between the combustion air a and the grate block 11 are increased, and the block main body 12 and the front wall 13 are effectively cooled. Is done. Further, the combustion air a is blown from the nozzle port 20 into the combustion chamber 2 at an inclination angle θ, and the waste is combusted on the combustion surface 12b.

  According to the above-described embodiment, the front of the adjacent grate block 11 disposed adjacent to the rear side is formed by forming the nozzle port 20 for injecting combustion air upward from the combustion surface 12b at the front front portion of the block body 12. The waste can be locally burned at the wall 13 and the part away from the front wall 13 of the grate block, and the front wall 13 can be prevented from being exposed to high heat due to local combustion. . Further, the combustion air a flowing into the introduction passage 18 from the guide passage 17 is once detoured downward by the partition portion 21a, and further introduced into the introduction passage 18 through the inclined inner surface 13c of the front wall portion 13, whereby the combustion air a Can be effectively cooled by sufficiently contacting the partitioning portion 21a and the inclined inner surface 13c of the front wall portion 13 respectively. Thereby, it is possible to effectively prevent the front wall portion 13 of the grate block 11 from being cracked or melted, and to prevent the molten metal from entering the sliding surface 12a and being fixed or cracking. be able to.

  Moreover, since the ejection angle θ is provided in the combustion air ejected from the nozzle port 20, the local combustion site can be shifted forward and further separated from the front wall portion 13 of the adjacent grate block 11 on the sliding surface 12a. The overheating of the front wall portion 13 can be effectively prevented. Further, by inclining the inclined inner surface 13c of the introduction passage 18 in parallel with the ejection angle θ in order to form the ejection angle θ, the lower portion of the front wall portion 13 can be formed sufficiently thick and the durability is improved. be able to.

  Furthermore, since the slide piece 19 is detachably attached to the lower end surface of the front wall portion 13 through the engagement groove 13d, the slide piece 19 can be easily replaced and wear measures can be easily taken.

  In addition, the nozzle opening 20 is formed in a slit shape that is long in the front-rear direction, which is the moving direction of the movable grate train (the moving direction of the waste), thereby preventing the intrusion of the waste and promptly removing the invading waste. The nozzle port 20 can be prevented from being clogged.

  FIG. 7 is a diagram illustrating an analysis result of the surface temperature distribution during use of the grate block 11 of the embodiment. FIG. 8 is a comparative example, and is a diagram showing the analysis result of the surface temperature distribution during use of the conventional grate block of Patent Document 3. From this analysis result, it was found that the surface temperature of the front wall portion 13 can be reduced by about 30 ° C. compared to the comparative example. Moreover, it turned out that the surface temperature of the sliding surface 12a can be reduced about 40 degreeC compared with a comparative example. As a result, it has been found that a sufficient cooling effect can be obtained.

It is a longitudinal cross-sectional view which shows embodiment of the grate block of the waste incinerator which concerns on this invention. It is a bottom side perspective view of a grate block. It is a top surface side perspective view of a grate block. It is an enlarged vertical sectional view of an introduction passage. It is a partial longitudinal cross-sectional view of a hearth part. It is a perspective view which shows a hearth part. It is a perspective view which shows the surface temperature distribution of a grate block. It is a perspective view which shows the surface temperature distribution of the conventional grate block. It is a longitudinal cross-sectional view which shows other embodiment of a grate block.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hearth part 3 Fixed grate row | line | column 4 Movable grate row | line | column 11 Grate block 12 Block main body 12a Sliding surface 12b Combustion surface 13 Front wall part 13c Inclined inner surface 13d Engaging groove 14 Rear wall part 15 Bracket part 15a Fitting space 16A Outer vertical rib 16B Inner vertical rib 17 Guide passage 18 Introduction passage 19 Slide piece 20 Nozzle port 21 Partition member 21a Partition portion 22 Support shaft (drive shaft)
23 Mounting plate

Claims (3)

A grate block installed in the hearth,
At the bottom of the block main body, the rear wall part protrudes downward at the rear part in the waste feed direction, and the front wall part protrudes downward at the front part,
A plurality of concave portions in the front-rear direction are formed between the front wall portion and the rear wall portion on the bottom surface of the block main body, and these concave portions serve as guide passages for guiding combustion air forward from the rear portion,
Forming a nozzle port through the block body at the front end portion of the guide passage and ejecting combustion air upward from the top surface;
On the rear side of the nozzle opening of the guide passage, a partition part is provided that forms an introduction passage to the nozzle opening between the front wall part,
A grate block for a waste incinerator characterized in that the partitioning portion causes the combustion air guided forward along the guide passage to be detoured downward and then led to the introduction passage. The grate block of the waste incinerator according to claim 1, wherein the introduction passage is inclined so that the combustion air ejected from the nozzle port is inclined upward in the front part with respect to the top surface of the block body. . Grate blocks are installed in fixed grate rows arranged alternately in the front-rear direction on the hearth and movable grate rows that can reciprocate in the front-rear direction,
The grate block of the waste incinerator according to claim 1, wherein the nozzle port is formed in a slit shape along the front-rear direction.

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