JP2013195052A - Fire grate in stoker-type waste incinerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fire grate capable of enduring long-term use while suppressing thermal damage to the fire grate by efficiently cooling not only a fixed fire grate but also, in particular, a tip wall and a top wall of the fire grate which receive severe thermal damage, in a stoker-type waste incinerator.SOLUTION: In a fire grate of a stoker-type waste incinerator, a movable fire grate 1 is formed in an upside down U-shape, a section 1B thereof includes a front wall 1C having a front face 1a rising from a lower end section, and at least one vent hole 3 longitudinally penetrating through the front wall 1C, is formed.

Description

  The present invention relates to improvement of a grate in a stalker-type waste incinerator.

  Various types of support devices or installation configurations for stalker-type garbage incinerator grate have been proposed. A movable grate and a fixed grate are arranged side by side, and they are arranged in multiple stages. The basic structure is common in that the waste grate is sent forward by sliding the movable grate relative to the fixed grate.

These movable grate and fixed grate have a slidable structure, are severely worn and damaged due to long-term use at high temperatures, and long-term even if they are made of cast steel. In view of the fact that it is difficult to withstand the use of a waste incinerator, a considerable amount of cooling air, for example, an incinerator with a waste treatment capacity of about 2 tons / h is placed below the stalker of the waste incinerator at 10,000 m ³ / h. About 70% of the air flow, and the air temperature is lowered so that the surface temperature of the grate of the stalker can be suppressed to about 400 ° C. to 500 ° C. or less. Note that the air volume of 70% also contributes to combustion by passing through the gap between the grates to the upper combustion space.
The following is mentioned as literature which shows said prior art.

JP 2002-221309. JP-A-2005-214589. JP2003-97807A. Patent 3922993

Problems to be solved by the invention

  Between each grate mentioned above, and especially between each movable grate and fixed grate (usually arranged like a piano black key (movable grate: upper side) and white key (fixed grate: lower side)) The gaps are formed between the grates so that the sliding movement can be smoothly performed, and the cooling air is allowed to escape from the individual gaps to the upper combustion space side (70% described above). The air flow is designed to be able to perform the desired combustion while reducing the flow path resistance and cooling the grate, but in this case, the cooling is mainly in the gap. It was a side wall of the grate, and cooling the tip of the grate was difficult to expect. As a result, thermal damage and wear of the tip of the grate, especially the tip wall of the movable grate and the top wall of the grate, which are heavily loaded when pushing dust, are prone to progress, causing problems for long-term use, It had to be replaced in a relatively short period of time.

In order to avoid or reduce such thermal damage of the grate, means as described in Patent Document 4 cited above has been proposed.
Such an air-cooling nozzle and an additional structure for supplying air to the nozzle have the disadvantage that the entire grate is complicated and the cost is significantly increased.

  The present invention has been devised in view of such a problem, and in a stoker-type waste incinerator, not only the fixed grate but also the tip wall and the upper surface wall of the movable grate which are particularly thermally damaged are efficiently cooled. The goal is to perform well and to withstand long-term use with less thermal damage to the grate.

Means for solving the problem

  In order to achieve the above object, the grate in the stoker-type waste incinerator according to the present invention is configured such that the main body (1A) of the movable grate (1) has a downward U-shape, and the movable grate An inclined wall having a front wall (1C) having a front surface (1a) from which a front end (1B) of the grate (1) rises from a lower end, and an inclined surface (1b) extending rearward and upward from the front wall (1C) (1D) and an upper surface wall (1G) connected to the inclined wall (1D), and the movable grate (1) is configured in the same manner as the movable grate (1) and is vertically Stoker type configured to be slid against the fixed grate (2) arranged so as to overlap, so that the garbage above these grate can be forwarded A grate in a garbage incinerator of the grate (1) Serial to the front wall (1C), and wherein the which had been opened at least one vent hole (3) penetrating in the front-rear direction.

The stoker-type waste incinerator referred to in the present invention refers to all existing types of stoker-type.
Although the present invention has been described in detail with respect to the movable grate, it is not only applicable to both movable and fixed grate (the structure is basically the same), but also the high temperature generation described in the embodiments. It is not limited to a grate in a combustion zone stalker (combustion bed), and can be applied to a grate in a dry zone and a post-combustion zone if necessary. .

Effect of the invention

According to the present invention, in the stoker-type garbage incinerator, not only the fixed grate, but also the tip wall and the top wall of the movable grate, which are particularly thermally damaged, are efficiently cooled, so that the heat of the grate It has become possible to suppress damage and withstand long-term use.
Other advantages of the present invention will become apparent from the following description.

  In carrying out the present invention, the ventilation hole (3) is opened in the movable grate (1), and the inside of the U-shape of the main body (1A) is along the longitudinal direction of the movable grate (1). At least one rib (1E) is spaced from the both side walls (1F, 1F) of the U-shaped main body (1A) by a predetermined distance from the rear end (1H) side of the main body (1A). It is preferable to be provided so as to be connected to the front wall (1C), and the ventilation holes (3) are opened at least one by one in the front wall (1C) at both sides of the rib (1E).

  With this configuration, the rib (1E) originally provided to increase the strength of the grate serves as a guide for the cooling airflow, and the cooling airflow is on both sides of the rib (1E) and the main body (1A). By flowing along the walls (1F, 1F), it comes out from the front vent hole (3) to the front of the grate while making contact with the substantially entire inner surface of the U-shaped main body (1A) of the grate. Thus, the cooling efficiency of the tip wall and the top wall of the movable grate can be further improved.

  The rear end (1H) of the movable grate (1) is placed on the movable support (4), and is formed below the rear end (1H) of the movable grate (1). The fitting recess (1e) is pivotally engaged with the movable grate connecting rod (5) located above the movable support (4) from above, and comprises a spring (7). An urging mechanism (6) is located in front of the movable support (4) and the movable grate connecting rod (5) of the movable grate (1) and between the lower part (1d). It is preferable that the tip (1B) of the movable grate (1) is urged downward by the spring (7).

  When configured as described above, the movable grate (1) from the movable grate connecting rod (5) is lifted due to biting of dust or combustion ash from the lower end of the movable grate (1). ), The cooling efficiency of the spring (7) of the urging mechanism (6) is improved by improving the flow of cooling air below the movable grate (1). Thus, the effect of preventing such dropout can be maintained over a long period of time.

The whole perspective view of the principal part of the grate of the refuse incinerator concerning this invention. The schematic front view which shows the drive system of the grate of the refuse incinerator concerning this invention. The top view of the grate concerning the present invention. The bottom view of the grate concerning the present invention. The side view of the grate concerning the present invention. The AA arrow directional cross-sectional view in FIG. 5 of the grate concerning this invention. The front view of the principal part which shows the action state of the grate concerning this invention. The front view of the principal part which shows the action state of the grate concerning this invention. The side view which shows another aspect of the grate concerning this invention. FIG. 10 is a cross-sectional view of the grate according to the present invention taken along line BB in FIG. 9. The front view of the principal part which shows the urging | biasing mechanism of the movable grate concerning this invention.

The grate of the stoker-type waste incinerator according to the present invention will be described in detail below with reference to the drawings.
FIG. 1 is an overall perspective view of the main part of a grate, and a plurality (15 in this case) of fixed grate 2 arranged in a horizontal row are held on a machine base 9 via a lower fixed support 8. Similarly, a plurality of (here, 16) movable grate 1 arranged in a horizontal row are held on the machine base 9 via the lower movable support 4. Here, although the combustion grate is quoted, there is usually a dry grate on the upper side and a post-burning grate on the lower side.

  The fixed support body 8 and the movable support body 4 are, as shown in FIG. 2, a cross beam material 10 that supports the side by side fixed support bodies 8 and a cross beam material 11 that supports the side by side movable support bodies 4. It is composed of a fixed support material and a movable support material for supporting the cross beam members 10 and 11, and the fixed support material is fixed to a part of the machine base 9, and the upper and lower two-stage movable support materials. Are connected to each other, and a drive mechanism 12 to be described later is interlocked with each other, and is supported by a roller support structure (two places in the front-rear direction) of the machine base 9 so as to be movable back and forth.

  3 to 6 show a plan view, a bottom view, a side view, and a longitudinal side view taken along the line AA in FIG. 5 of one movable grate 1. The fixed grate 2 has substantially the same configuration. Although not shown here, for convenience, only the symbol of the front wall 2C of the fixed grate 2 is placed beside the front wall 1C of the movable grate 1. It is written together. Here, the movable grate 1 is made of cast steel having a total length of about 560 mm, a total width of about 120 mm, and a total height of about 120 mm (weight of about 20 kg). From the bottom view of FIG. 4 and the side view of FIG. As can be seen, two ribs 1E and 1E are formed in the inside along the longitudinal direction. In FIG. 3, reference numeral 13 denotes a positioning hole, which protrudes from a movable grate connecting rod 5 fixed thereon when the movable grate 1 is placed on the movable support 4 from above. The pin 14 is fitted (see FIG. 6). The pin 14 is provided at a position corresponding to each movable grate 6.

A main body 1A of the movable grate 1 is configured to have a U-shaped downward cross-sectional shape, and a front wall 1C having a front surface 1a where a front end portion 1B of the movable grate 1 rises from a lower end portion; An inclined wall 1D having an inclined surface 1b extending rearward and upward from the front wall 1C, and an upper surface wall 1G subsequent thereto are provided.
In this embodiment, the front wall 1C of the movable grate 1 is provided with at least one ventilation hole 3 penetrating in the front-rear direction, in this case, three ventilation holes 3 having a diameter of about 7 mm. . Here, the ventilation hole 3 is formed so that the inner surface side of the front wall 1C has a large diameter and the front surface 1a side has a small diameter cross section.

Further, at least one rib 1E along the longitudinal direction of the movable grate 1 inside the U-shape of the main body 1A, in this case, two ribs 1E and 1E are the U-shaped main body. 1A side walls 1F, 1F are provided so as to be connected to the front wall 1C from the rear end 1H side of the main body 1A at a predetermined interval, and the ventilation holes 3 are arranged at both sides of the rib 1E. At least one each is opened in the front wall 1C.
The total opening area of such ventilation holes 3 is designed to be about 7% to 10% of the cooling air flowing below (about 70% of the entire blower air volume), which will be described later, as a grate for the entire stalker. . Of course, this air volume adjustment can be adjusted by changing the number of perforations when the diameter of the vent hole 3 is changed to 7 mm.

  And the fixed grate 2 and the movable grate 1 can be moved so that the lower surface of the tip 1B of the movable grate 1 can be slidably contacted with the upper surface of the fixed grate 2 on the garbage feed direction side. In a state where the movable grate 1 is positioned on the upper side of the feed direction and the fixed grate 2 is positioned on the lower side, a plurality of steps (here, five steps) are alternately arranged in the direction of waste. Is arranged.

In FIG. 1 and FIG. 2, here, the staircase shape is arranged in the order of the movable grate 1 from the upper side of the garbage feed direction, and the fixed grate 2 below the movable grate 1, and is fixed to the lowest level. A grate 2 is arranged. However, this stepped arrangement may be further multi-staged depending on the size of the waste incinerator.
The movable grate 1 is arranged so as to straddle the side-by-side connecting portions of the lower fixed grate like a black keyboard and a white keyboard of a piano, and is not arranged vertically.

The fixed grate 1 and the movable grate 2 are configured so as to be detachably mounted on the fixed support 8 and the movable support 4 from above.
In this installation structure, the rear end 1H of the movable grate 1 is placed on the movable support 4, and a fitting recess 1e formed below the rear end 1H of the movable grate 1 is provided. The movable grate connecting rod 5 positioned on the upper side of the movable support 2 is pivotally engaged from above. ,

Then, a driving mechanism 12 is interlocked and connected to the movable support 1 so that the movable grate 1 can be slid with respect to the fixed grate 2 so that garbage thrown in from above can be sent forward. It is configured.
In this embodiment, the drive mechanism 12 uses a hydraulic cylinder 12A, and the tip of the piston rod is connected to the movable support 4. The drive mechanism 12 may be replaced with a mechanical system such as a crank using an electric motor that is an existing system.

The floor side below the movable grate 1 and the fixed grate 2 described above is configured as an air cooling passage, and a large amount of air flows from the rear side to the front side by a blower (not shown). Have been to. Incidentally, an incinerator having a waste treatment capacity of about 2 t / h, such as an embodiment of the present invention, is configured such that a flow rate of about 70% of 10000 m ³ / h flows (the flow rate is about 1 m / sec). .

(Function)
According to the movable grate 1 configured as described above, when the cooling air flows from the rear to the front, the U-shaped due to the presence of the ventilation holes 3 drilled in the front wall 1C of the front end portion 1B. The air flow along the inner side of the main body 1A is easily formed, and as a result, the contact of air with the inner surface of the upper surface wall 1G of the main body 1A is increased, the cooling efficiency of the upper surface wall 1G is improved, and the front surface By passing through the wall 1C, the cooling of the front wall 1C itself proceeds. It has been found that if a ventilation hole is opened in the inclined wall 1D, the cooling effect of the lower end portion of the front wall 1C is deteriorated.
In particular, since the movable grate 1 is moved back and forth, as shown in FIG. 7 and FIG. 8, a gap is generated between the front surface 1a of the front wall 1C and the lump of dust at the moment of retreating after the forward movement, and forward. The discharge resistance is reduced, the flow of cooling air is smooth, and the air cooling effect is enhanced.

Normally, the upper wall 1G and the front wall 1C of the movable grate 1 are heated to about 400 ° C. to 500 ° C. However, as a result of the experiment, the movable grate having the ventilation holes 3 due to the presence of the ventilation holes 3 described above. For 1, compared to a movable grate without ventilation holes 3, the upper wall 1G can see a temperature drop of about 30 to 50 ° C., and the front wall 1C can see a temperature drop of about 50 to 80 ° C., and the temperature drop width is large. Although this is not the case, it was possible to suppress the temperature to around 400 ° C., which is the transition range of the mechanical strength of the metal.
In the temperature detection of this experiment, the temperature sensor of the thermocouple is arranged so that the movable grate 1 with the vent hole 3 and the movable grate without the vent hole 3 are disposed adjacent to each other, and the inner upper wall of the movable grate 1 and The comparison was made by providing it on the inner surface of the front wall.
Thereby, the thermal damage of the movable grate 1 can be significantly reduced, and the life of the grate can be greatly extended, thereby contributing to cost reduction.

(Some variations)
FIG. 9 and FIG. 10 show that the above-mentioned one ventilation hole 3 has a smaller diameter (about 5 m) than the embodiment, and two holes are drilled side by side vertically between the rib 1E and the side wall 1F. Thus, six ventilation holes 3 are formed in the front wall 1C of one movable grate 1, and by forming in this way, the amount of air passing through the ventilation holes 3 does not change, but by making the diameter small Thus, it is possible to prevent air from entering the small lump from the front face 1a and avoid air clogging.
In addition, it is known that by using the plurality of ventilation holes 3, the flow of air going forward is smooth, and the passing speed (1 m / sec) does not decrease.

(Another aspect)
As shown in FIG. 11, of the fixed grate 2 and the movable grate 1, here, a tip portion 1 </ b> B of the movable grate 1 has a predetermined pressure against the upper surface of the fixed grate 2. Each of the urging mechanisms 6 for pressure contact is provided.
Here, the urging mechanism 6 comprises a spring 7 interposed between the movable support 2 and the rear end 1H of the movable grate 6.

  Specifically, the biasing mechanism 6 includes a coil spring 7A interposed between a bracket 6a laid on the rear end portion 11H of the movable grate 1 and a bracket 6b laid on the movable support 2. It consists of a bolt 6c and a nut 6d inserted through both brackets 6a and 6b, so that the distal end portion 1A of the movable grate 1 pivots (fits) the movable grate connecting rod 5 by the spring 11. It is configured to be urged downward as a pivot by play of the joint recess 1c.

The repulsive force of the coil spring 7A is adjusted by adjusting the tightening of the bolt 6c and nut 6d so that an appropriate contact pressure with respect to the fixed grate 2 of the tip 6B of the movable grate 1 is obtained. .
Here, from the verification test, the contact pressure is determined by the weight of the movable grate 1 so as to enable the escape operation in an abnormal situation while suppressing the biting of dust from the tip portion 6A of the movable grate 6. It has been found that the contact pressure by (20 kg) is preferably within a range that increases by 10 to 30%, and a coil spring 7A that generates such a contact pressure is used. However, the object can also be achieved by increasing the contact pressure by about 30% to 50%.

  According to the grate configured as described above, the tip 1A of the movable grate 1 is in pressure contact with the upper surface of the lower fixed grate 2 with a predetermined pressing force by the spring 7 of the urging mechanism 6. Then, it is moved back and forth by the drive mechanism 12. Accordingly, even if dust lump or foreign matter comes into contact with the tip 1B of the movable grate 1 and the traveling resistance increases, it does not rise easily. As a result, it is possible to avoid the accident of dropping the movable grate 1 from the movable support 4 and the movable grate connecting rod 5 due to the entire floating of the movable grate 1 due to the biting of dust or the like.

  In addition, the resistance of the movable grate 1 and the fixed grate 2 is locked so that the movement of the movable grate 1 and the fixed grate 2 is locked due to a great load on the movable grate 1, an abnormal vibration of the entire apparatus, an unexpected situation of the drive mechanism 12, and the like. Is applied to the movable grate 1, the spring 7 of the urging mechanism 6 acts to allow a slight upward escape of the movable grate 1 at the front end 1 </ b> B. The operation of the grate 1 can be continued to avoid a situation where the operation of the incinerator is stopped, and an opportunity for natural restoration can be obtained.

  The function of the movable grate 1 by the urging mechanism 6 is achieved by the spring 7 as described above. However, the vent hole 3 is formed in the front wall 1C of the movable grate 1 as in the present invention. Thus, the flow of the cooling air on the lower side of the movable grate 1 is improved. As a result, the spring 7 is also cooled, and the fluctuation of the elastic coefficient of the spring due to heat is reduced. It is easy to maintain the urging function of the front end portion 1B sufficiently over a long period of time.

  Since the grate of the refuse incinerator according to the present invention can be applied to any type of stalker, its application range is wide.

1: movable grate 1A: main body 1B: tip 1C: front wall 1D: inclined wall 1E: rib 1F: side wall 1G: top wall 1H: rear end 1a: front 1b: inclined surface 1c: fitting recess 1d: down Side part 2: Fixed grate 3: Ventilation hole 4: Movable support 5: Movable grate connecting rod 6: Energizing mechanism 7: Spring

Claims (3)

The main body (1A) of the movable grate (1) is configured to have a downward U-shape, and the front end (1B) of the movable grate (1) has a front surface (1a) rising from the lower end. A front wall (1C), an inclined wall (1D) having an inclined surface (1b) extending rearward and upward from the front wall (1C), and an upper surface wall (1G) connected to the inclined wall (1D), and The movable grate (1) is configured in the same manner as the movable grate (1) and is configured to be slid with respect to the fixed grate (2) arranged so as to overlap each other. Therefore, a grate in a stoker-type garbage incinerator configured to be able to send the garbage above these grate forward,
At least one ventilation hole (3) penetrating in the front-rear direction is opened in the front wall (1C, 2C) of the grate (1, 2).
A grate in a stoker-type waste incinerator characterized by that. The ventilation hole (3) is opened in the movable grate (1),
Inside the U-shape of the main body (1A), at least one rib (1E) along the longitudinal direction of the movable grate (1) is provided on both side walls (1A) of the U-shaped body (1A). 1F, 1F) at a predetermined distance from the rear end (1H) side of the main body (1A) so as to be connected to the front wall (1C),
The ventilation holes (3) are opened at least one by one in the front wall (1C) at both sides of the rib (1E),
A grate in a stoker-type waste incinerator according to claim 1. The rear end (1H) of the movable grate (1) is placed on the movable support (4),
A fitting recess (1e) formed on the lower side of the rear end (1H) of the movable grate (1) has a movable grate connecting rod (5) positioned on the upper side of the movable support (4). ) Is pivotally engaged from above,
An urging mechanism (6) comprising a spring (7) is located on the front side of the movable support (4) and the movable grate connection rod (5) of the movable grate (1), and a lower portion thereof. (1d), and is configured such that the tip (1B) of the movable grate (1) is biased downward by the spring (7).
A grate in a stoker-type waste incinerator according to claim 2.

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