JPH0926123A - Step type stoker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide always uniform air distribution irrespective of a refuse layer on a fire bed in a step type stoker which is applicable to a refuse incinerator. SOLUTION: Each of fire grates 2 and 3 comprises a fire grate body 4, a nozzle hole 5, an air guide member 6 and an elastic member 7. Especially, the nozzle hole 5 is formed on the lower end of the front of the fire grate member 4 which is fixed to a fire bed frame 8 and of a box-shape. The air guide member 6, which forms an air passage 15 inside the fire grate member 4 is provided upwardly turnably. The elastic member 7 is provided so as to cause the tip of the air guide member 6 to engage with the upper wall 9 of the fire grate 4 on the front side which is in constant contact therewith.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a step type stoker applied to, for example, a refuse incinerator.

[0002]

2. Description of the Related Art Conventionally, as this type of stepped stoker, for example, those shown in FIGS. 5 to 7 have been known. The stair type stoker 50 has a fixed grate 51 and a movable grate 52 alternately arranged in a stepwise manner. Each grate 5
1, 52 are attached to the fire bed frame 53, and the fire bed frame 53 for the movable grate is the operation frame 5
It is attached to 4. When the reciprocating drive device (not shown) is operated, the operation frame 54 is moved in the front-back direction on the slide 55, the movable grate 52 is reciprocated with respect to the fixed grate 51, and dust is upstream of the fire bed. Will be incinerated while being transferred downstream. An ash discharging hopper 56 for receiving falling ash is provided below the fire bed, and a falling ash conveyor (not shown) for discharging the falling ash is provided below the ash discharging hopper 56. Combustion air A is sent into the ash discharge hopper 56, and the grate 5 is discharged.
The nozzle holes 57 (gap formed between the adjacent upper and lower grate pieces 51, 52) formed at the tips of the nozzles 1, 52 are ejected into the dust layer to burn the dust. The grate body 58 forming each of the grates 51 and 52 is provided with fins 59 for lowering the temperature, and heat is dissipated by the contact of the combustion air A. The dust layer on the stairs stoker 50 is a mixture of miscellaneous substances such as paper, plastic, kitchen waste, bamboo, cans, glass, etc., and the burning of the paper and plastic is fast, and these create a through hole in the dust layer. Combustion air blows through to prevent uniform combustion of the dust layer, causing uneven burning and reducing the amount of ash burned. Therefore, in order to perform complete combustion, a large fire area is required.

[0003]

However, in the conventional one, since the combustion air is simply ejected from the nozzle holes of each grate through the inside of the ashing hopper, it is not possible to determine whether a dust layer on the fire bed is present. However, it was not always possible to achieve a uniform air distribution. The present invention was devised in order to solve this problem in view of the above problems, and the object of the invention is to:
It is to provide a stepped stoker that can always provide a uniform air distribution regardless of the dust layer on the fire bed.

[0004]

The step-type stoker of the present invention is basically a step-type stoker in which fixed grate and movable grate are alternately arranged in the front-rear direction. The grate is a hollow box-shaped grate that is fixed to the grate frame and has open front and bottom sides, and a nozzle hole formed at the lower front side of the grate body. The air guide body, which is provided so as to be able to lift up and down, forms an air passage reaching the nozzle hole from the rear side of the grate body between the upper wall and the front wall of the grate body, and the tip of the air guide body is always adjacent. It is characterized by being composed of an elastic body slidably fitted to the upper wall of the front grate body. Each grate is preferably provided with a predetermined forward elevation angle.

When the movable grate is reciprocated in the front-back direction with respect to the fixed grate by the reciprocating drive device, the refuse is incinerated while being transferred from the upstream side to the downstream side of the fire bed. The combustion air is
From the rear side of each grate body, it passes through the air passage formed by the air guide body and is jetted from the nozzle hole. Therefore, the combustion air supplied into the ash discharge hopper is ejected at a high speed from the nozzle holes formed on the front side of each grate body and at the same amount of discharged air. As a result, a uniform air distribution can always be obtained regardless of the dust layer on the fire bed. This time,
The combustion air cools the upper wall and the front wall of each grate body.
Therefore, burning of the grate can be prevented. The air guide body is provided so that it can be lifted up and down on each grate body, and the tip of the air guide body is always slidably fitted to the upper wall of the front side grate body that is adjacent to the grate body, so that it passes through the air passage. The air does not leak from here, and the incineration ash or the like that has entered through the nozzle holes can be extruded and blown into the dust layer by the jet air. Since the tip end of the air guide body is forcedly engaged by the elastic body, the sealing action and the pushing action are surely performed.
When each grate is tilted by a predetermined forward elevation angle, the stirring action of the dust is improved.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional side view showing an outline of a stepped stoker according to the present invention. FIG. 2 is a cross-sectional view of FIG.
It is a front view which shows each arrow of A, BB, CC, DD, and EE. In the staircase stoker 1, a fixed grate 2 and a movable grate 3 are alternately arranged in the front-rear direction (trash feed direction, left-right direction in FIG. 1), and each grate 2, 3 is a grate body. 4, a nozzle hole 5, an air guide body 6, and an elastic body 7. The grate body 4 is fixed to the fire bed frame 8 and has a hollow box shape in which the lower half and the rear half are open.
In this example, the upper wall 9 and the front wall 1 connected to the front side of the upper wall 9
0, left and right side walls 11 provided on both sides of these, a lower wall 12 connecting these rear lower parts, a vertical wall extending across the upper wall 9 and the front wall 10 in the longitudinal direction. It is composed of a plurality of (three) fins 13 provided. The corners of the upper wall 9 and the front wall 10 are inclined. The lower wall 11 of each grate body 4 is attached by bolts 14 to a fire bed frame 8 having a substantially H-shaped cross section. The nozzle hole 5 is formed at the lower front side of the grate body 4, and in this example,
The lower end of the front wall 10 of the grate body 4 is cut off and formed between the upper wall 9 of the adjacent grate body 4 on the front side. The air guide body 6 is provided in the grate body 4 so that it can be lifted up and down around the horizontal axis, and between the upper wall 9 and the front wall 10 of the grate body 4 from the rear side of the grate body 4 to the nozzle hole 5. It forms an air passage 15 that reaches, and in this example, it has a substantially L-shaped side face provided with a horizontal wall 16 and a vertical wall 17 extending downward from the front side thereof, and the middle of the horizontal wall 16 is the horizontal axis 18. Therefore, the side wall 11 of the grate body 4
It is pivoted so that it can be lifted up and the shoe 1 is attached to the bottom of the vertical wall 17.
9 are attached. An air passage 15 is formed between the horizontal wall 16 and the upper wall 9 and between the vertical wall 17 and the front wall 10 to reach the nozzle hole 5 from the rear side of the grate body 4. The space between the vertical wall 17 and the front wall 10 is made narrower than the space between the horizontal wall 16 and the upper wall 9 to increase the air pressure loss. The shoe 19 is made of a metal having a high sealing property,
The vertical wall 17 is detachably attached by means of dovetails and dovetail grooves. The elastic body 7 slidably engages the tip end of the air guide body 6 with the upper wall 9 of the adjacent front grate body 4, and in this example, the horizontal mounting piece 20 and the rear mounting piece 20 are provided. It is composed of a tongue piece 21 which is continuous obliquely upward from the end and whose tip is bent, and has a triangular shape lacking one corner.
Is attached to the lower wall 12 of the grate body 4 using bolts 14, and the upper end of the tongue piece 21 is a horizontal wall 16 rearward of the horizontal axis 18.
I am urged to constantly increase this when I am hit by.

FIG. 3 is a vertical cross-sectional side view showing a stair stoker in which the grate of FIG. In the stairs stoker 1, the fire bed frame 8 for the fixed grate 2 is attached to the fixed side, and the fire bed frame 8 for the movable grate 3 is attached to the operation frame 22. The operation frame 22 is supported by a roller 23 rotatably provided around the horizontal axis on the fixed side so as to be movable back and forth.
It is designed to reciprocate in the front-back direction depending on No. 4. Although not shown, an ash discharging hopper for receiving the fall ash is provided under the fire bed, and a fall ash conveyor for discharging the fall ash is provided under the hopper. Thus, the stairs stoker 1 is installed on the fixed side so that the grates 2 and 3 are inclined by a predetermined forward elevation angle θ (θ = 35 °). The forward tilt angle θ is, for example, 50 ° beyond the horizontal, preferably 10 to 40.
°, particularly preferably 20 to 30 °. If it is smaller than this range, the efficiency of stirring the dust tends to be poor, and if it is larger than this range, the efficiency of conveying the dust tends to be poor.

Next, the operation will be described based on such a configuration. When the reciprocating drive device 24 is actuated, the actuating frame 22 is moved in the front-back direction on the roller 23, the movable grate 3 is reciprocated with respect to the fixed grate 2, and dust is transferred from upstream to downstream of the fire bed. While being incinerated. Combustion air A
Is pressed into the air passage 15 from the rear side of the grate body 4 through the inside of the ashing hopper, and the upper wall 9 and the front wall 10 of the grate body 4 are
Is ejected from the nozzle hole 5 at the tip while cooling the back surface of the.
At this time, the combustion air A flows between the fins 13,
As the heat dissipation area increases, the air velocity also increases and the heat transfer rate can be increased. In the grate body 4, the front side of the air passage 15 is squeezed into a nozzle shape and the combustion air A is ejected at a high speed. Therefore, the combustion ash is blown away, the air velocity of the tip portion where the heat consumption is large is increased, and the cooling effect is achieved. The air resistance can be added at the same time. As a result, the amount of air discharged from each grate 2, 3 can be made equal, and a uniform air distribution can always be obtained regardless of the dust layer on the fire bed. At this time, the combustion air A is supplied to the upper wall 9 and the front wall 10 of each grate body 4.
And to cool. Therefore, even if the radiant heat from the dust layer is received, the burnout of the grate 2 or 3 can be prevented. Since the air guide body 6 is provided so as to be lifted up on each grate body 4 and is slidably fitted to the upper wall 9 of the front side grate body 4 whose tip is always adjacent by the elastic body 7, The combustion air A passing through the air passage 15 does not leak from here, and the incineration ash or the like that has entered from the nozzle holes 5 can be extruded and blown into the dust layer by the jet air. Since the tip end of the air guide body 6 is forcibly engaged by the elastic body 7, the sealing action and the pushing action are surely performed. Since the air guide body 6 has a function of forming the air passage 15, a function of preventing leakage of the combustion air A passing through the air passage 15, and a function of pushing out incineration ash or the like that has entered from the nozzle hole 5. , Very reasonable. Since the elastic body 7 uses the bolt 14,
Since it is rational and located outside the air passage 15, it does not interfere with the flow of the combustion air A. As shown in FIG. 3, when the grates 2 and 3 are inclined by a predetermined forward elevation angle θ, the effect of feeding and lifting the dust is enhanced, and the stirring action of the dust is improved. Therefore, it is possible to efficiently burn even low-calorie waste.

FIG. 4 is a schematic vertical sectional side view showing an example in which the stairs stoker of FIG. 3 is applied to a refuse incinerator. The waste incinerator 25 includes a waste hopper 26, a dust feeding device 27, a drying stoker 28, a combustion stoker 29, an ash discharging hopper 30, a falling ash conveyor 31, an auxiliary combustion burner 32, an ash discharging flight conveyor 33, and the like. The dry stoker 28 and the combustion stoker 29 are installed on the fixed side so that the respective grates 2 and 3 are inclined by a predetermined forward elevation angle θ (θ = 20 °). Such a thing can solve all the conditions of the ideal grate shown below. Air supply (compartmentalization) …… The amount of supplied air can be finely controlled in the direction of waste flow. The structure should allow the air supply to be compartmentalized. Pressure drop in the grate: The air pressure loss in the grate should be increased so that air can be supplied uniformly from above the grate. Ridling: A structure that does not allow dust, molten aluminum, or plastics to fall from the gap in the grate. Grate cooling rate: A large grate cooling rate should be used to prevent burnout. Grate burning rate: A structure that has a large dust agitation effect and a large grate burning rate. Grate with low furnace height (horizontal grate) .... A structure that can reduce the furnace height by eliminating the steps between grate and using horizontal grate. Maintenance (easy) …… A structure that facilitates maintenance. Grate drive method (step control) ........ A structure that allows the stroke of the grate to be adjusted for each combustion process.

In the above example, the corners of the upper wall 9 and the front wall 10 of the grate body 4 are inclined, but the invention is not limited to this.
For example, an arc shape may be used. In the previous example, the operation frame 22 was supported by the roller 23, but the present invention is not limited to this.
For example, as in the conventional case, it may be slidably supported by a slide.

[0011]

As described above, according to the present invention, as described above,
The following excellent effects can be obtained. (1) Each grate is composed of a grate body, a nozzle hole, an air guide body, and an elastic body, and in particular, a nozzle hole is formed at the lower front side of the grate body which is fixed to the fire bed frame and has a hollow box shape. However, since an air guide body that forms an air passage is provided in the grate body so that the air guide body can be lifted up, and an elastic body that constantly engages the tip of the air guide body with the upper wall of the adjacent front grate body is provided, Regardless of the dust layer, it is possible to always obtain a uniform air distribution. (2) Since the air guide body is provided in the grate body so that it can be elevated, and the tip of the air guide body is slidably fitted to the upper wall of the adjacent front grate body by the elastic body, the nozzle is It is possible to extrude incineration ash that has entered through the holes and prevent it from falling below the stoker. (3) Since the air passage is formed by the air guide body, it is possible to prevent the tip portion of each grate from being burnt out. (4) When each grate is inclined by a predetermined forward elevation angle, it is possible to enhance the stirring effect of the dust layer and to make a stoker with good combustion efficiency.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view showing an outline of a stepped stoker according to the present invention.

2 is A-A, B-B, C-C, D-D, E- of FIG.
The front view which shows each arrow of E.

FIG. 3 is a vertical cross-sectional side view showing a stair-type stoker in which the grate of FIG. 1 is installed with an inclination.

FIG. 4 is a schematic vertical sectional side view showing an example in which the stairs stoker shown in FIG. 3 is applied to a refuse incinerator.

FIG. 5 is a perspective view showing the structure of a conventional stair type stoker for incinerating refuse.

FIG. 6 is an operation diagram showing a retracted state of the movable grate.

FIG. 7 is a similar view showing a forward state of the movable grate.

[Explanation of symbols]

1,50 ... Stair stoker, 2,51 ... Fixed grate,
3, 52 ... Movable grate, 4, 58 ... Grate body, 5, 57
... Nozzle hole, 6 ... Air guide, 7 ... Elastic body, 8, 53 ...
Fire bed frame, 9 ... upper wall, 10 ... front wall, 11 ... side wall, 1
2 ... Lower wall, 13, 59 ... Fin, 14 ... Bolt, 15 ...
Air passage, 16 ... Horizontal wall, 17 ... Vertical wall, 18 ... Horizontal axis,
19 ... Shoe, 20 ... Mounting piece, 21 ... Tongue piece, 22 ... Actuating frame, 23 ... Roller, 24 ... Reciprocating drive device, 25 ...
Garbage incinerator, 26 ... Garbage hopper, 27 ... Dust feeder, 2
8 ... Dry stoker, 29 ... Combustion stoker, 30, 56 ...
Ash discharge hopper, 31 ... Falling ash conveyor, 32 ... Burning burner, 33 ... Ash discharge flight conveyor, 55 ... Slide, A ...
Combustion air, θ ... Forward elevation angle.

Claims (2)

[Claims] 1. A stepped stoker in which a fixed grate and a movable grate are alternately arranged in the front-rear direction, and each of the grate is fixed to a fire bed frame to open the lower half and the rear half of the first half. A hollow box-shaped grate body, a nozzle hole formed at the front lower end of the grate body, and an upper wall and a front wall of the grate body which are provided so as to be able to rise and fall around the horizontal axis. Between the air grate and the air guide that forms an air passage from the rear side of the grate to the nozzle hole, and the elasticity that always slidably engages the tip of the air guide with the upper wall of the adjacent front grate. A staircase stoker characterized by being composed of a body and a body. 2. The stairs-type stoker according to claim 1, wherein each grate is provided so as to be inclined by a predetermined forward elevation angle.