Incinerator stoker structure

Abstract

To provide a stoker structure of an incinerator capable of suppressing vibration of an operating grate with a simple structure at low cost.SOLUTION: A stoker structure of an incinerator comprises a vibration prevention mechanism 10 including a pair of guide rollers 11, 11 that are supported by a fixed grate support member Af and are arranged opposite each other along an axial direction of the fixed grate support member Af and a guide member 15 that is supported by a movable frame Fm and is arranged so as to extend between the pair of guide rollers 11, 11, and configured to support vibration in a width direction of the movable frame Fm when the movable frame Fm is reciprocated.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a stoker structure for an incinerator. [Background technology]

[0002] As shown in Patent Document 1, a stoker structure for an incinerator has been proposed in which fixed grates supported by fixed grate support members hung horizontally along the width direction of a fixed frame and movable grates supported by movable grate support members hung horizontally along the width direction of a movable frame are arranged alternately in the transport direction of the material to be incinerated, and a drive mechanism is provided to move the fixed grates and movable grates relative to each other by driving the movable frame back and forth relative to the fixed frame.

[0003] In the stoker structure of this incinerator, a certain amount of clearance is provided between the fixed frame and the movable frame so that the movable frame can smoothly reciprocate regardless of the effects of thermal expansion, etc. Also, to prevent gaps from being formed between the fire grates arranged in the furnace width direction, side walls are provided on the left and right sides of the furnace width direction, which are pressed toward the center in the width direction by springs. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 09-033016 Summary of the Invention [Problem to be solved by the invention]

[0005] In incinerators that use this type of stoker structure, if the movable frame, which is driven back and forth in the transport direction of the material to be incinerated, swings obliquely across the width of the furnace, ash and other particles can become stuck in the gaps between the grates or between the grates and the side walls, hindering smooth movement.

[0006] Therefore, for example, it was necessary to provide a large-scale and costly anti-vibration mechanism that involves providing a beam between the left and right frames that support the wind box, connecting support parts erected at both ends of the beam with supported parts installed so as to extend to both left and right ends of the movable frame via freely rotatable rollers, and using flanges on both ends of the rollers to prevent the supported parts from vibrating in the furnace width direction relative to the support parts.

[0007] In view of the above-mentioned problems of the conventional art, an object of the present invention is to provide a stoker structure for an incinerator that is simple in structure and inexpensive and can suppress the vibration of a movable fire grate. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the first characteristic configuration of the stoker structure of an incinerator according to the present invention is a stoker structure for an incinerator in which fixed grates supported by fixed grate support members hung horizontally along the width direction of the fixed frame and movable grates supported by movable grate support members hung horizontally along the width direction of the movable frame are arranged alternately in the transport direction of the material to be incinerated, and which is equipped with a drive mechanism that moves the fixed grates and the movable grates relative to each other by driving the movable frame back and forth relative to the fixed frame, and which is equipped with a vibration prevention mechanism that suppresses vibration of the movable frame in the width direction when the movable frame is driven back and forth, including a pair of guide rollers supported by the fixed grate support members and arranged opposite each other along the axial direction of the fixed grate support members, and a guide member supported by the movable frame and arranged to extend between the pair of guide rollers.

[0009] When the movable frame is driven back and forth by the drive mechanism, the guide member supported by the movable frame moves back and forth while sandwiched between a pair of guide rollers supported by the fixed grate support member, and the pair of guide rollers prevents vibration in the furnace width direction. This type of vibration prevention mechanism has a simple structure and can be constructed inexpensively.

[0010] The second characteristic configuration is that, in addition to the first characteristic configuration described above, the guide roller is arranged to be freely rotatable inside a pair of guide plates suspended from the fixed grate support member.

[0011] The guide roller can be supported with a simple structure.

[0012] The third characteristic feature of the present invention is that, in addition to the second characteristic feature described above, a cover member is provided in the gap between the pair of guide plates to prevent ash from falling.

[0013] Ash and other particles that fall through the gaps in the fixed grate supported by the fixed grate support member are received by the cover member, preventing the guide rollers from becoming dirty, eliminating the need for frequent maintenance and enabling stable operation over a long period of time.

[0014] The fourth characteristic configuration is a stoker structure for an incinerator in which fixed grates supported by fixed grate support members hung horizontally along the width direction of a fixed frame and movable grates supported by movable grate support members hung horizontally along the width direction of a movable frame are arranged alternately in the transport direction of the material to be incinerated, and which is equipped with a drive mechanism that moves the fixed grates and the movable grates relative to each other by driving the movable frame back and forth relative to the fixed frame, and which is equipped with a vibration prevention mechanism that suppresses vibration of the movable frame in the width direction when the movable frame is driven back and forth, including a pair of guide rollers supported by the movable frame and arranged opposite each other along the axial direction of the movable grate support member, and a guide member supported by the fixed grate support member and arranged to extend between the pair of guide rollers.

[0015] When the movable frame is driven back and forth by the drive mechanism, a pair of guide rollers supported on the movable frame reciprocate while a guide member supported on a fixed grate support member is sandwiched between the pair of guide rollers, thereby preventing vibration in the furnace width direction. This type of vibration prevention mechanism has a simple structure and can be constructed inexpensively.

[0016] The fifth characteristic feature of the present invention is that, in addition to the first or fourth characteristic feature described above, the anti-vibration mechanism is provided at an upstream portion and a downstream portion of the movable frame along the conveying direction.

[0017] By providing a plurality of anti-vibration mechanisms at the upstream and downstream sides along the conveying direction of the movable frame, that is, at intervals along the conveying direction, effective anti-vibration can be achieved.

[0018] The sixth characteristic configuration is that, in addition to the first or fourth characteristic configuration described above, a wind box that supplies combustion air is installed below the fixed frame, and the drive mechanism is installed outside the wind box.

[0019] Even if ash or unburned waste falls into the wind box through gaps in the movable or fixed grate, the drive mechanism is installed outside the wind box, so frequent maintenance is not required and stable operation is possible for a long period of time.

[0020] The incinerator according to the present invention is characterized by a stoker mechanism that transports and incinerates materials that are fed into a garbage hopper and then pushed into a furnace chamber by a dust feeder, and the stoker mechanism A device having any one of the first to fourth characteristic configurations described above. The incinerator is constructed with a stoker structure. [Effects of the Invention]

[0021] As described above, according to the present invention, it is possible to provide a stoker structure for an incinerator that is simple in structure and inexpensive, and that can suppress the vibration of the operating grate. [Brief explanation of the drawings]

[0022] [Figure 1] Schematic explanatory diagram of a plan view of a stoker structure with a fixed frame and a movable frame. [Figure 2] (a) is a front view of the main part of the stoker structure, (b) is a BB cross section of (a), and (c) is a CC cross section of (b). [Figure 3](a) is a plan view of the anti-vibration mechanism, (b) is a front view of the anti-vibration mechanism, and (c) is a DD cross-sectional view of (b). [Figure 4] (a) is a cross-sectional view of the main part of the anti-vibration mechanism, and (b) is an E-E cross-sectional view of (a). [Figure 5] Diagram of a waste incinerator [Figure 6] (a) to (d) are explanatory diagrams of the waste transport operation by the movable grate. DETAILED DESCRIPTION OF THE INVENTION

[0023] The stoker structure of an incinerator according to the present invention will be described below with reference to the drawings. FIG. 5 shows an example of an incinerator 1 incorporating a stoker mechanism that employs the stoker structure of the present invention.

[0024] The incinerator 1 is a municipal waste incinerator that incinerates household waste and other materials collected by waste trucks and accumulated in a waste pit. The waste accumulated in the waste pit is dumped into a waste hopper 3 by a waste crane 2.

[0025] A hydraulically driven dust feeder 4 attached to the bottom of the waste hopper 3 pushes waste into the furnace chamber 5. The furnace chamber 5 comprises a main combustion chamber 5A and a secondary combustion chamber 5B, which completely combusts the flue gas generated in the main combustion chamber 5A in the space above it, with multiple water tubes for a waste heat boiler embedded in the wall of the secondary combustion chamber 5B. The flue gas flows out of the furnace outlet 7 above the secondary combustion chamber 5B into the flue, where it is purified by flue gas treatment equipment such as a temperature reducing tower and dust collector arranged along the flue before being exhausted from the chimney. An induced draft fan is installed in the flue to maintain a negative pressure in the furnace chamber 5.

[0026] The main combustion chamber 5A is equipped with a stoker mechanism S, in which fixed and movable grates are arranged alternately along the direction of waste transport. The stoker mechanism S is divided into three zones from upstream to downstream: a drying zone S1, a combustion zone S2, and a post-combustion zone S3. The movable grates are reciprocated back and forth relative to the fixed grates by hydraulic mechanisms (hydraulic cylinders) h1, h2, and h3, respectively, to agitate the waste and transport it downstream.

[0027] Four wind boxes W1, W2, W3, and W4 are provided below the stoker mechanism S in this order from upstream to downstream, and primary combustion air is supplied from a forced draft fan. The upstream region corresponding to wind box W1 of the stoker mechanism S is the drying zone S1, the midstream region corresponding to wind boxes W2 and W3 is the combustion zone S2, and the downstream region corresponding to wind box W4 is the post-combustion zone S3.

[0028] Narrowed sections are formed in the front and rear walls of the furnace chamber 5 from the main combustion chamber 5A to the inlet of the secondary combustion chamber 5B, and a gas supply mechanism 6 for secondary combustion is provided in the narrowed sections. The combustion exhaust gas flowing into the secondary combustion chamber 5B is agitated and rectified by the gas supplied from the gas supply mechanism 6, and is completely combusted in the secondary combustion chamber 5B.

[0029] The gas supplied from the gas supply mechanism 6 may be air for secondary combustion, exhaust gas extracted from the main combustion chamber 5A, recirculated exhaust gas branched from the flue downstream of the dust collector, or exhaust gas branched from another exhaust gas flow path, or may be a mixture of air and each of the exhaust gases.

[0030] As shown in Figure 6(a), the base end Rb of each grate R is supported by columnar support shafts Am and Af, and the tip end Rh is supported by the upper surface of the grate R located downstream. Primary combustion air supplied from a wind box located below the grate R is guided into the cavity Rc, and part of it is supplied to the waste above through an opening formed at the tip and part through the gap between the adjacent grates. Note that if the grate R is a water-cooled type, a cooling medium passage is formed inside it, and if it is an air-cooled type, heat dissipation fins are formed on the bottom surface.

[0031] As shown in Figure 6(b), multiple movable grates Rm are arranged in parallel in the furnace width direction along a support axis Am, which is a movable grate support member supported by a movable frame not shown, and multiple fixed grates Rf are arranged in parallel in the furnace width direction along a support axis Af, which is a fixed grate support member supported by a fixed frame not shown.

[0032] The fixed grates Rf and movable grates Rm that make up the stoker mechanism S are arranged alternately in the direction of waste transport, and the movable frame is driven back and forth by hydraulic mechanisms (hydraulic cylinders) h1, h2, h3 (see Figure 5), causing the movable grate Rm to move back and forth between a forward position and a backward position.

[0033] The movable grate Rm moves back and forth while sliding on the top surface of the fixed grate Rf between the forward position shown in Figure 6(c) and the backward position shown in Figure 6(d), so that the refuse on the top surface of each grate R is pushed out by the tip Rh of the upstream grate R, and is stirred and transported. Figure 6(b) shows the movable grate Rm in the intermediate position.

[0034] The stoker structure is described in detail below. FIG. 1 shows a schematic plan view of the stoker structure. A movable frame Fm, also rectangular in plan view, is arranged inside a fixed frame Ff, which is also rectangular in plan view. Cylindrical fixed grate support members Af are laid horizontally on the fixed frame Ff at regular intervals along the direction of waste transport, with each end fixed and supported to the fixed frame Ff by support members M. Cylindrical movable grate support members Am are laid horizontally on the movable frame Fm at regular intervals along the direction of waste transport, with each end fixed and supported by support members M. The fixed grate support members Af and movable grate support members Am are arranged alternately along the direction of waste transport.

[0035] The fixed grate support member Af has a plurality of fixed grates Rf arranged along its axis, and the movable grate support member Am has a plurality of movable grates Rm arranged along its axis, with the tip of the upstream grate resting on the back of the downstream grate. Although not shown in Figure 1, a drive mechanism including a hydraulic cylinder that reciprocates the movable frame Fm relative to the fixed frame Ff is provided on both sides of the fixed frame Ff in the width direction.

[0036] Between the fixed grate support member Af located upstream along the conveying direction and the movable frame Fm located nearby, and between the fixed grate support member Af located downstream along the conveying direction and the movable frame Fm located nearby, there is provided a vibration prevention mechanism 10 that suppresses vibration of the movable frame Fm in the width direction when the movable frame Fm moves back and forth.

[0037] 2(a) and (b) show the drive mechanism 20 that drives the movable frame Fm to reciprocate. The drive mechanism 20 includes a hydraulic mechanism 20A that drives the movable frame Fm to reciprocate in the front-to-rear direction, and a support mechanism 20B that supports the movable frame Fm driven by the hydraulic mechanism 20A.

[0038] The relative movement of the fixed grate Rf and the movable grate Rm creates gaps between the grates or between the grates and the side wall SW, and to prevent garbage and ash from falling or clogging, both ends of the fixed grate Rf and the movable grate Rm, which are arranged in the furnace width direction, are pressed by the side wall SW, which is pressed by the pressing mechanism SP.

[0039] A pair of brackets 23 extend downward from two positions along the front-to-rear direction of the movable frame Fm, i.e., along the direction in which the waste is transported, and a support shaft 22 is fixed to each bracket 23. Support mechanisms 20B are provided at both ends of the two support shafts 22, and hydraulic mechanisms 20A are provided at both ends of one support shaft 22.

[0040] The hydraulic mechanism 20A comprises a pair of hydraulic cylinders 21 installed on the base frame F of the incinerator 1, and the pistons of each hydraulic cylinder 21 are fixed to the respective ends of a single support shaft 22. When the pistons are driven forward, the movable frame Fm is moved forward obliquely upward and forward via the support shaft 22, and when the pistons are driven backward, the movable frame Fm is moved backward obliquely downward.

[0041] The support mechanism 20B includes an inclined guide plate 24 installed on the base frame F of the incinerator 1 and rollers 25 fixed to both ends of the support shaft 22. As the hydraulic cylinder 21 reciprocates, the rollers 25 rolling on the upper surface of the inclined guide plate 24 smoothly reciprocate the movable frame Fm via the support shaft 22.

[0042] The anti-vibration mechanism 10 is shown in FIG. 2(c), FIGS. 3(a) to (c), and FIGS. 4(a) and (b). The anti-sway mechanism 10 includes a pair of guide rollers 11 supported by the fixed grate support member Af and arranged opposite each other along the axial direction of the fixed grate support member Af, and a flat guide member 15 supported by the movable frame Fm and arranged to extend between the pair of guide rollers 11, and is a mechanism that suppresses vibration in the width direction of the movable frame Fm when the movable frame Fm is driven back and forth.

[0043] The guide roller 11 is arranged to rotate freely inside a pair of guide plates 12 that hang down from the axial center of the fixed grate support member Af. One end of the pair of guide plates 12 is welded to the fixed grate support member Af, and a pair of holding plates 13 that hold the guide roller 11 extend from each of the opposing surfaces of the pair of guide plates 12. The guide roller 11 is arranged between the pair of holding plates 13, and a pin P is fitted and fixed between the holding plates 13 and the guide roller 11 in a manner that prevents it from coming out.

[0044] The guide member 15 is fixed by bolts via mounting members 16 to the widthwise center of the movable frame Fm located near the fixed fire grate support member Af on which the guide rollers 11 are provided.

[0045] The inclination angle θ of the inclined guide plate 24 relative to the horizontal plane (see Figure 2(a)), the inclination angle θ of the guide member 15, and the inclination angle φ of the guide roller 11 relative to the vertical plane (see Figure 3(c)) are set to be equal values. The guide member 15 attached to the movable frame Fm, which is driven back and forth by the drive mechanism 20, is clamped between a pair of guide rollers 11 attached to the fixed grate support member Af, thereby preventing it from vibrating in the width direction, thereby enabling smooth reciprocating movement.In addition, the formation of gaps in the fixed grates Rf and movable grates Rm, which are arranged in the furnace width direction, that could allow garbage or ash to fall or become clogged, is minimized.

[0046] Furthermore, as shown in Figure 3(c), even if ash or the like falls toward the fixed fire grate support member Af, a cover member 30 is provided in the gap between the pair of guide plates 12 to prevent the ash or the like from falling, so that the guide roller 11 is not contaminated by falling ash or the like. As a result, frequent maintenance is not required, and stable operation is possible over a long period of time.

[0047] By providing two or more anti-sway mechanisms 10 at upstream and downstream portions along the transport direction of the movable frame, that is, at a distance apart along the transport direction, effective anti-sway can be achieved. In the above example, the anti-sway mechanism 10 is installed in the center in the width direction, that is, in the center in the longitudinal direction of the fixed grate support member Af. However, the installation position of the anti-sway mechanism 10 is not limited to the center in the width direction, and it may also be installed in a position offset to either the left or right side of the center. However, all installation positions of the two or more anti-sway mechanisms 10 must be the same offset position.

[0048] As described above, it is preferable that the drive mechanism 20 is installed outside the wind box W that supplies combustion air and is installed below the fixed frame Ff. Even if ash or unburned material falls from the fire grate, the drive mechanism 20 will not be contaminated. Frequent maintenance is no longer necessary, and stable operation is possible over a long period of time.

[0049] In the above-described embodiment, an example was described in which the anti-sway mechanism 10 is constructed by attaching a pair of guide rollers 11 to the fixed grate support member Af and attaching a guide member arranged to extend between the pair of guide rollers 11 to the movable frame.However, the anti-sway mechanism 10 may also be constructed by including a pair of guide rollers supported by the movable frame Fm and arranged opposite each other along the axial direction of the movable grate support member Am, and a guide member supported by the fixed grate support member Af and arranged to extend between the pair of guide rollers, thereby suppressing the widthwise vibration of the movable frame Fm when the movable frame Fm is driven back and forth. Even in this case, it goes without saying that if a cover member is provided above the guide roller 11 on the guide plate 12 over the range of reciprocating movement of the movable frame Fm, the guide roller can be prevented from being contaminated by falling debris such as ash.

[0050] The above-described embodiment is merely an example of the present invention, and the technical scope of the present invention is not limited by the description. Furthermore, it goes without saying that the specific structure, materials, size, installation mode, etc. of each part can be appropriately modified and designed within the scope of the effects of the present invention. [Explanation of symbols]

[0051] 1: Incinerator 10: Vibration prevention mechanism 11: Guide roller 12: Guide plate 13: Holding plate 15: Guide member 16: Mounting material 20: Drive mechanism 20A: Hydraulic mechanism 20B: Support mechanism 30: Cover material Af: Fixed grate support member Am: Movable grate support member Ff: Fixed frame Fm: Movable frame Rf: Fixed grate Rm: Movable grate S: Stoker mechanism SW: Side wall

Claims

1. A stoker structure for an incinerator in which fixed grates supported by fixed grate support members laid horizontally along the width direction of a fixed frame and movable grates supported by movable grate support members laid horizontally along the width direction of a movable frame are arranged alternately in the transport direction of the material to be incinerated, and a drive mechanism is provided to move the fixed grates and the movable grates relative to each other by reciprocating the movable frame relative to the fixed frame, A stoker structure for an incinerator equipped with a vibration-prevention mechanism that suppresses vibration in the width direction of the movable frame when the movable frame is reciprocated, the vibration-prevention mechanism including a pair of guide rollers supported by the fixed grate support member and arranged opposite each other along the axial direction of the fixed grate support member, and a guide member supported by the movable frame and arranged to extend between the pair of guide rollers.

2. 2. The incinerator stoker structure according to claim 1, wherein the guide rollers are arranged freely rotatably inside a pair of guide plates suspended from the fixed grate support member.

3. 3. The stoker structure for an incinerator according to claim 2, further comprising a cover member for preventing ash from falling into the gap between the pair of guide plates.

4. A stoker structure for an incinerator in which fixed grates supported by fixed grate support members laid horizontally along the width direction of a fixed frame and movable grates supported by movable grate support members laid horizontally along the width direction of a movable frame are arranged alternately in the transport direction of the material to be incinerated, and a drive mechanism is provided to move the fixed grates and the movable grates relative to each other by reciprocating the movable frame relative to the fixed frame, A stoker structure for an incinerator equipped with a vibration prevention mechanism that suppresses vibration of the movable frame in the width direction when the movable frame is reciprocated, the vibration prevention mechanism including a pair of guide rollers supported by the movable frame and arranged opposite each other along the axial direction of the movable grate support member, and a guide member supported by the fixed grate support member and arranged to extend between the pair of guide rollers.

5. 5. The incinerator stoker structure according to claim 1, wherein the anti-vibration mechanism is provided at an upstream portion and a downstream portion of the movable frame along the conveying direction.

6. 5. The stoker structure for an incinerator according to claim 1, wherein a wind box for supplying combustion air is installed below said fixed frame, and said drive mechanism is installed outside said wind box.

7. An incinerator equipped with a stoker mechanism that transports and incinerates materials that are thrown into a garbage hopper and then pushed into the furnace chamber by a dust feeder. An incinerator, wherein the stoker mechanism is constructed by the stoker structure of an incinerator according to any one of claims 1 to 4.

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