JP2012159263A - Waste melting disposal method and system thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste melting disposal method and a system thereof that can stably operate by resolving biased loading of thermal decomposition residual substance in a thermal decomposition residual substance melting part.SOLUTION: In the waste melting disposal method where waste is charged in a drying shaft part 1 which dries the waste from the top of drying shaft part 1 to form waste packed bed, while drying the waste by passing the gas generated both in a fire grate part 2 which generates a thermal decomposition residual substance and in a thermal decomposition residual substance melting part 3 which melts thermal decomposition residual substance by making coke as a heat source through the waste packed bed formed, the gas passing through the waste packed bed is discharged from the top of drying shaft part 1, then the waste dried in the drying shaft part 1 is decomposed thermally in the fire grate part 2 into thermal decomposition residual substance 19, and finally the thermal decomposition residual substance 19 that has been generated is continuously dropped from the fire grate part 2 to supply into the thermal decomposition residual substance melting part 3 for melting, compressed inert gas is jetted off by Blaster 22 to a thermal decomposition residual substance 19 which drops from the fire grate part 2 to be partially loaded to the thermal decomposition residual substance melting part 3 for resolving partial loading.

Description

  The present invention relates to a waste melting apparatus in which a drying shaft portion and a pyrolysis residue melting portion are connected to each other via a grate portion, and the thermal decomposition residue in the pyrolysis residue melting portion for melting the pyrolysis residue is unevenly distributed. It relates to the technology to be solved.

  In a shaft furnace type waste melting furnace that melts waste, there is a large amount of high-moisture waste such as garbage and volatile matter such as wood in the waste. When the volatile matter is lowered to the lower part of the furnace without being gasified, both moisture and volatile matter lower the ambient temperature. Therefore, in order to maintain the atmospheric temperature high and completely melt the non-combustible material, it is necessary to increase the amount of coke used as a result.

  Therefore, in waste melting treatment, drying and thermal decomposition are performed separately from combustion and melting to remove moisture and volatiles in the waste, and the waste is lowered to the bottom of the furnace without being dried or pyrolyzed. To suppress the consumption of coke used for melting ash by lowering the ambient temperature at the bottom of the furnace, thereby achieving complete melting with the heat of the pyrolysis residue and the heat of a small amount of coke. A waste melting treatment technique that can be used has been proposed (see Patent Document 1).

  As shown in FIG. 4, the waste melting furnace shown in Patent Document 1 thermally decomposes the waste dried by the drying shaft 1 and drying shaft 1 for drying the charged waste. It comprises a melting furnace 6 having a grate part 2 for generating a pyrolysis residue and a pyrolysis residue melting part 3 for burning and melting the pyrolysis residue at the bottom. The drying shaft portion 1 is disposed above the entrance side of the grate portion 2, and the pyrolysis residue melting portion 3 is disposed below the exit side of the grate portion 2, communicated with the crank shape and integrally provided. ing. In addition, the thermal decomposition residue etc. which fell from the grate part 2 are discharged | emitted by the ash conveyance apparatus.

  The pyrolysis residue melting part 3 includes a lower hearth part 4 and a morning glory part 5 connected to the hearth part 4. The hearth part 4 is provided with a lower tuyere 7 for blowing air and oxygen as an oxygen source. An upper tuyere 8 for blowing air into the morning glory portion 5 may be arranged. A coke bed 18 is formed in the pyrolysis residue melting part 3 in the same manner as the bottom of a conventional shaft furnace type waste melting furnace. Auxiliary materials such as coke and limestone are fed from the auxiliary material inlet 15 at the top of the melting furnace 6.

  An exhaust gas outlet 9 and a waste charging inlet 10 are provided at the top of the drying shaft portion 1, and the waste charging inlet 10 is provided with a sealing lid 11 for preventing gas from blowing out during charging. . A waste transfer device 12 such as a pusher is provided below the drying shaft portion 1.

  The grate part 2 includes a grate 13 that moves the waste charged from the drying shaft part 1 to the pyrolysis residue melting part 3 while thermally decomposing the waste. Reference numeral 16 denotes an activation burner, and 17 denotes a tuyere for blowing combustion air into the drying shaft portion.

  In the waste melting apparatus having the above-described configuration, the waste packed bed formed by charging from the waste inlet 10 at the top of the drying shaft portion 1 is generated from the grate portion 2 and the pyrolysis residue melting portion 3. Gas passes through and is efficiently heat exchanged for drying and pyrolysis. The pyrolysis residue 19 generated by pyrolyzing the waste dried in the drying shaft portion 1 in the grate portion 2 falls into the pyrolysis residue melting portion 3 and is burned and melted by the heat source of the coke bed 18. Then, it is discharged from the outlet 14 of the hearth part 4. The exhaust gas passes through the waste of the drying shaft portion 1 and is exhausted from the exhaust gas outlet 9.

  In the waste melting apparatus, the pyrolysis residue 19 is continuously dropped and filled into the pyrolysis residue melting part 3 from the residue outlet at the end of the grate 2, but depending on the filling height, the lower tuyere 7 blown air and the pyrolysis residue 19 are mixed to cause abnormal combustion, the amount of scattering of the pyrolysis residue 19 increases due to fluidization of the pyrolysis residue 19, or the pressure loss in the packed bed increases. If it becomes difficult to continue blowing, or the blowing pressure must be set very high, it becomes difficult to ensure stable melting.

  Therefore, in Patent Document 1, in order to perform stable melting while maintaining the filling height of the pyrolysis residue 19 supplied into the pyrolysis residue melting part 3 at a predetermined level, a micro-arrangement disposed above the melting furnace 6 is used. The filling height of the pyrolysis residue 19 is continuously measured using the wave level meter 20, and from the grate portion 2 to the pyrolysis residue melting portion 3 so that the filling height is maintained at a predetermined level from the measurement result. The thermal decomposition residue supply speed, the blown air amount and the auxiliary material input amount are adjusted.

JP 2010-255890 A

  In Patent Document 1, pyrolysis from the grate part 2 into the pyrolysis residue melting part 3 is performed so that the filling height of the pyrolysis residue 19 in the pyrolysis residue melting part 3 is maintained at a certain level. The residue supply speed, the flow rate of blown air, and the amount of auxiliary material input are adjusted. By these adjustments alone, the residue outlet of the grate part 2 is suspended by the upper part of the pyrolysis residue 19 or the shelf hanging in the grate part 2. The pyrolysis residue 19 falling from the bottom is liable to be piled up on the residue outlet side, and it is difficult to keep the height of the pyrolysis residue 19 uniform.

  Oxygen being blown locally from the lower tuyere to the upper part due to uneven accumulation of pyrolysis residue causes oxidative melting reaction at the upper part of the furnace, causing clinker adhesion, or stable operation cannot be continued, or coke Or hindered the reduction.

  In addition, when the pyrolysis residue is unevenly deposited, coke and limestone charged from the upper part of the pyrolysis residue melting part will also be unevenly accumulated, and if the coke is unevenly distributed, heat will not be distributed evenly to the furnace bottom. An area with a low temperature is locally formed and deposits are formed. In addition, when limestone is unevenly accumulated, local basicity variation occurs and fluidization of the melt deteriorates, and stable operation cannot be performed.

  Accordingly, the present invention eliminates the uneven accumulation of the pyrolysis residue in the pyrolysis residue melting portion in the waste melting apparatus in which the drying shaft portion and the pyrolysis residue melting portion are connected via the grate portion. The present invention provides a waste melting method and apparatus capable of stable operation.

  In the waste melting method of the present invention, the waste is charged into the drying shaft portion from the top of the drying shaft portion for drying the waste to form a waste filling layer, and the formed waste filling layer is Waste gas is dried by passing the gas generated in the grate part that generates the pyrolysis residue and coke as a heat source, and the pyrolysis residue melting part of the melting furnace is passed through, and the waste packed bed is The gas that has passed through is discharged from the top of the drying shaft section, and the waste dried by the drying shaft section is pyrolyzed at the grate section to generate a pyrolysis residue, and the generated pyrolysis residue is continuously from the grate section. In the waste melting treatment method in which it is dropped and supplied to the pyrolysis residue melting part of the melting furnace and melted, it is compressed by a blaster to the pyrolysis residue layer that falls from the grate part to the pyrolysis residue melting part and accumulates Inert gas is ejected and unbalanced Characterized in that it eliminated.

  In the waste treatment apparatus of the present invention, a waste charging inlet and an exhaust gas exhaust outlet are provided at the top, and the grate portion and the heat are added to the waste filling layer formed by charging waste from the waste charging inlet. The waste gas is dried by passing the gas generated in the decomposition residue melting part, and the drying shaft part where the gas that has passed through the waste packed bed is discharged from the exhaust gas exhaust port is connected to the lower part of the drying shaft part. It is connected to the grate part that generates pyrolysis residue by pyrolyzing the waste dried by the drying shaft part, and the pyrolysis residue exit side of the grate part is dropped and supplied from the grate part In the waste treatment equipment in which the pyrolysis residue melting part of the melting furnace is sequentially arranged with the coke as the heat source, the pyrolysis residue is dropped into the pyrolysis residue melting part and becomes an unbalanced pyrolysis residue. Eliminate uneven distribution by jetting compressed inert gas Characterized in that a blaster.

  In the present invention, the height of the pyrolysis residue layer can be leveled by ejecting a compressed inert gas with a blaster to the pyrolysis residue that accumulates in the pyrolysis residue melting portion. As a result, since oxidative melting due to partial escape of oxygen to the upper part due to uneven accumulation is suppressed, adhesion of clinker is prevented and stable operation can be continued.

  In addition, since the pyrolysis residue height is leveled, the uneven distribution of coke and limestone charged from the upper part of the melting furnace is eliminated, and heat is evenly distributed. As a result, no locally low-temperature areas are formed, so that no deposits are formed, and there is no local variation in basicity due to the uneven accumulation of limestone, preventing deterioration of the fluidization of the melt. it can.

  In addition, since the thermal decomposition residue has a low specific gravity, it is possible to easily eliminate the shelf suspension or the like by blowing out the compressed inert gas of the blaster.

It is the schematic of the waste melting furnace of this invention. It is a layout of the blaster of the waste melting furnace of the present invention. It is another arrangement | positioning drawing of the blaster of the waste melting furnace of this invention. It is the schematic of the conventional waste melting furnace.

  In the waste melting apparatus of the present invention shown in FIG. 1, the same components as those of the conventional waste melting furnace shown in FIG.

  In FIG. 1, the waste melting apparatus of the present invention is a drying shaft portion 1 for drying and pyrolyzing the charged waste, and further decomposing the waste dried and pyrolyzed by the drying shaft portion 1. And a pyrolysis residue melting section 3 that burns and melts the pyrolysis residue generated in the grate section 2. The drying shaft portion 1 is disposed above the entrance side of the grate portion 2, and the pyrolysis residue melting portion 3 is disposed below the exit side of the grate portion 2, communicated with the crank shape and integrally connected. Yes.

  A waste charging inlet 10 and an exhaust gas outlet 9 are provided at the top of the drying shaft portion 1. A waste filling layer is formed by the waste charged from the waste loading inlet 10 in the drying shaft portion 1. The gas generated in the grate part 2 and the pyrolysis residue melting part 3 passes through the waste packed bed to dry the waste by heat exchange, and the gas passing through the waste packed bed is discharged from the exhaust gas outlet 9 at the top. Is done.

  The grate part 2 includes a grate 13 that moves the waste dried by the drying shaft part 1 to the thermal decomposition residue melting part 3 while generating a thermal decomposition residue by thermal decomposition. The grate part 2 is formed by combining the movable grate 2a and the fixed grate 2b alternately in a staircase shape or an inclined shape, as in the case of the stoker furnace. The waste on the grate is advanced from the upstream side to the downstream side while being agitated by reciprocating at a constant pitch in the front-rear direction with a driving device such as a cylinder. Air is blown into the grate portion 2 from below. By providing the grate structure, the supply of the pyrolysis residue 19 to the pyrolysis residue melting section 3 is continuous and stable, and the pyrolysis residue melting section 3 ensures stable melting of the pyrolysis residue. Is possible. In addition, the thermal decomposition residue etc. which fell from the grate part 2 are discharged | emitted by the conveyor 21. FIG.

  The pyrolysis residue melting part 3 includes a lower tuyere 7 for blowing air and oxygen as an oxygen source in the hearth part 4, and an upper tuyere 8 for blowing air into the morning glory part 5. In the hearth 4, a coke bed 18 is formed as in the conventional shaft furnace type waste melting furnace, and a hot water outlet 14 for pouring the melt is provided. Auxiliary materials such as coke and limestone are input from the auxiliary material inlet 15 at the top of the melting furnace 6.

  In the waste treatment apparatus having the above-described configuration, the grate portion 2 is formed on the waste filling layer formed by introducing waste into the drying shaft portion 1 from the waste inlet 10 at the top of the drying shaft portion 1. And when the exhaust gas generated in the thermal decomposition residue melting part 3 passes, heat exchange is performed and the waste is efficiently dried. The heat-exchanged gas that has passed through the waste filling layer of the drying shaft portion 1 is exhausted from the exhaust gas outlet 9.

  The waste dried by the drying shaft portion 1 is pyrolyzed by the grate portion 2 to generate a pyrolysis residue 19. The generated pyrolysis residue 19 falls and accumulates in the pyrolysis residue melting part 3 from the residue outlet on the exit side of the grate part 2, and is burned and melted by the heat source of the coke bed 18. The melt is discharged from the outlet 14 of the hearth part 4.

  The pyrolysis residue falls from the grate portion 2 on the coke bed in the pyrolysis residue melting portion 3, but the pyrolysis residue is deposited on the residue outlet side of the falling grate portion 2, Since it does not move uniformly to the opposite side, it becomes an inclined uneven accumulation state that is deposited low.

  In order to eliminate this uneven accumulation, in the present invention, a blaster 22 is arranged to level the thermal decomposition residue 19 unevenly accumulated in the thermal decomposition residue melting part 3.

In FIG. 2, a blaster 22 is installed in the pyrolysis residue volume part on the upper surface of the pyrolysis residue melting part 3 on the grate part 2 side of the pyrolysis residue melting part 3. One or a plurality of blasters 22 are installed according to the size of the pyrolysis residue melting portion 3. The blaster 22 is connected to a compressed inert gas source, for example, a compressed N ₂ gas source, via an on-off valve 23. By opening the on-off valve 23, the compressed inert gas is blown from the blaster 22 to the thermal decomposition residue 19 at once. Since the pyrolysis residue 19 has a small specific gravity and is light, the pyrolysis residue is blown up or blown around by the jetting of the compressed inert gas and is leveled.

  FIG. 3 shows an example in which a blaster 22 is installed on the side surface with respect to the inclination of the pyrolysis residue 19. Since the pyrolysis residue itself has a low specific gravity, it can be leveled even if a compressed inert gas is ejected from the side surface.

  The timing of ejection is monitored by the camera 20 installed in the upper part of the pyrolysis residue melting part, and when the uneven accumulation is observed, the blaster 22 is operated and leveled. Alternatively, before adding the auxiliary material from the auxiliary material inlet 15, the blaster 22 is operated and leveled so that the auxiliary material does not accumulate.

  In addition, by operating the blaster at regular time intervals with a timer, the pyrolysis residue can be blown up or blown out and leveled evenly regardless of the height of the pyrolysis residue layer. The time interval of the timer can be changed according to, for example, the amount of falling pyrolysis residue, that is, the grate speed.

Using each of the three blasters, N ₂ compressed gas having a pressure of 0.3 to 0.7 MPa per time could be simultaneously jetted into the pyrolysis residue to level the pyrolysis residue. The timer interval is adjusted in the range of about 30 seconds to 180 seconds.

1: Drying shaft part 2: Grate part 3: Pyrolysis residue melting part 4: Hearth part 5: Morning glory part 6: Melting furnace 7: Lower tuyere 8: Upper tuyere 9: Exhaust gas outlet 10: Waste equipment Inlet 11: Sealing lid 12: Waste supply device 13: Grate 14: Outlet 15: Secondary material inlet 16: Burner 17: Drying shaft tuyere 18: Coke bed 19: Pyrolysis residue 20: Level meter 21: Conveyor 22: Blaster 23: Open / close valve

Claims (7)

The waste is loaded into the drying shaft from the top of the drying shaft for drying the waste to form a waste filling layer,
Gas generated in the grate part that generates pyrolysis residue and the pyrolysis residue melting part that melts the pyrolysis residue using coke as a heat source is passed through the formed waste packed bed to dry and discard the waste. The gas that has passed through the packed bed is discharged from the top of the drying shaft,
Wastes dried on the drying shaft are pyrolyzed in the grate to produce pyrolysis residues,
In the waste melting treatment method in which the generated pyrolysis residue is continuously dropped from the grate portion and supplied to the pyrolysis residue melting portion of the melting furnace to be melted,
A waste melting method characterized in that a compressed inert gas is ejected by a blaster to a pyrolysis residue layer that has fallen from a grate portion to a pyrolysis residue melting portion and accumulated unevenly, thereby eliminating the uneven accumulation. The waste melting method according to claim 1, wherein the compressed inert gas is ejected by a blaster according to an uneven accumulation state observed by a camera installed at an upper portion of the pyrolysis residue melting portion. The waste melting method according to claim 1, wherein the compressed inert gas is ejected by a blaster before the auxiliary material is introduced into the pyrolysis residue melting part. 2. The waste melting method according to claim 1, wherein compressed air is ejected by a blaster at a constant time interval by a timer. A waste charging inlet and exhaust gas exhaust outlet are provided at the top, and the gas generated in the grate part and pyrolysis residue melting part is passed through the waste filling layer formed by charging waste from the waste charging inlet. And drying the waste, and a drying shaft portion through which the gas passing through the waste filling layer is discharged from the exhaust gas exhaust port,
A grate part that is connected to the lower part of the drying shaft part and pyrolyzes the waste material dried by the drying shaft part to generate a pyrolysis residue;
It is connected to the pyrolysis residue outlet side of the grate part, and the pyrolysis residue falling from the grate part is melted using coke as a heat source, and the pyrolysis residue melting part of the melting furnace is sequentially arranged Waste disposal equipment
A waste treatment apparatus comprising: a blaster that discharges a compressed inert gas to a pyrolysis residue that has fallen and accumulated on the pyrolysis residue melting portion to eliminate the accumulation. 6. The waste treatment apparatus according to claim 5, wherein the blaster is disposed on the grate portion side. 6. The waste treatment apparatus according to claim 5, wherein the waste treatment apparatus is disposed on the inclined side surface of the pyrolysis residue on which the blaster is deposited.

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