JP2007255816A - Waste supply device and waste treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste supply device capable of supplying waste to a combustion furnace and the like, while reducing fluctuation in the amount of waste, and stably preventing an outflow of gas and an inflow of air through a waste supply passage. <P>SOLUTION: The waste can be easily discharged from a refuse feeding hopper 4 by a pusher-type first refuse feeding device 5 even in a state that the waste is sufficiently stored in the refuse feeding hopper 4, and the gas and air are hardly circulated, and the waste can be stably supplied to the combustion furnace and the like with small fluctuation in the amount of waste by a screw-type second refuse feeding device 6 by performing an operation for securing an adequate amount of waste in a connection chute 6 continued from the refuse feeding hopper. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a waste supply apparatus and a waste supply for constantly supplying waste to a heat treatment furnace using a pyrolysis furnace, an incinerator or the like to treat waste such as municipal waste and industrial waste. The present invention relates to a waste treatment apparatus including the apparatus.

  Waste heat treatment furnaces, such as pyrolysis furnaces and incinerators, that treat waste such as municipal waste, generate heat from the combustion of the waste itself, and maintain combustion at a constant temperature. That is, the waste itself is used as a fuel, and the waste is heat-treated. For this reason, the supply of waste that greatly exceeds the treatment capacity of the treatment furnace raises the temperature in the furnace to a temperature higher than the heat resistance temperature, which is not desirable for durability.

  In addition, the supply of waste that greatly falls below the processing capacity of the processing furnace lowers the temperature in the furnace and prevents the self-combustion action due to the heat of the waste itself, so the temperature at which combustion continues using auxiliary fuel such as heavy oil It is necessary to keep Therefore, once the treatment in the waste heat treatment furnace is started, it is desirable that the supply of waste to the furnace is constantly maintained without fluctuation. In addition, the combustion gas from the combustion furnace is purified in the downstream process and released from the chimney to the atmosphere, but the stable operation in the combustion furnace also contributes to the performance in the downstream process.

  Conventionally, as a device for supplying waste to a combustion furnace, one using a screw type is disclosed in Patent Documents 1 and 2, for example. Moreover, the thing using a pusher type | formula is disclosed by patent document 3 and 4, for example. Patent Document 5 discloses a device using a screw type or pusher type supply device following a paddle type supply device.

Japanese Patent Laid-Open No. 10-19219 JP 2002-181316 A Japanese Patent Laid-Open No. 10-253025 Japanese Patent Laid-Open No. 2003-302018 JP 2001-221419 A

  These supply devices have also achieved the purpose of stable supply of waste to some extent, but are not always sufficient. In addition, since the waste supply path is a path connecting the atmosphere and the combustion furnace, gas from the combustion furnace flows out from the path through which waste is supplied to the combustion furnace, or air flows into the combustion furnace. There is a fear, and such a situation is not preferable for safety and stability of operation. Therefore, an object of the present invention is to enable supply with less fluctuation of the amount of waste and to stably prevent outflow of gas and inflow of air through the waste supply path.

  A waste supply apparatus according to a first aspect of the present invention that solves the above-described problem is provided with a dust supply hopper that has an open inlet for receiving waste at the top and an outlet at the bottom, and the waste collected in the dust hopper In the waste supply device for transferring the waste, a pusher type first dust supply device that has an inlet connected to an outlet of the dust supply hopper and pushes waste in a horizontal direction, and an upper portion is an outlet of the first dust supply device And a screw-type second dust supply device having an inlet connected to a lower portion of the connection chute.

  Even if the waste supply device stores sufficient waste in the dust supply hopper and makes it difficult for gas and air to flow, the push-type first dust supply device can easily supply waste. The amount of waste discharged from the screw-type second dust supply device can be made stable with a small fluctuation by performing an operation to secure an appropriate amount of waste in the connection chute. .

  A waste supply apparatus according to a second invention that solves the above problem is the apparatus according to the first invention, wherein a level sensor that detects the amount of waste accumulated on the connection chute, and a detection level of the level sensor is first. If it is lower than the predetermined level, the first dust supply device starts to transfer the waste to the connection chute. If the detection level is the second predetermined level higher than the first predetermined level, the first dust supply And a control device for stopping the transfer of waste by the device.

  With this waste supply device, the amount of waste accumulated in the connection chute is within a predetermined range, so that the screw-type second dust supply device has no waste or is packed too much, resulting in a waste transfer failure. It is possible to reliably stabilize and equalize the amount of waste discharged.

  A waste treatment apparatus according to a third invention for solving the above-described problems is provided with the waste heat treatment furnace in addition to the apparatus of the first or second invention, receiving the waste extruded from the second dust supply apparatus. It comprises a passage for discharging, and a waste heat treatment furnace for receiving and burning waste from the passage.

  By using the first or second invention as a means for supplying waste to the heat treatment furnace as in the configuration of the waste treatment apparatus, the performance of the heat treatment furnace can be exhibited efficiently and sufficiently.

  Waste supply can be in a stable state with little fluctuation in time, air inflow and gas outflow through the waste supply path can be suppressed, and the combustion state of the waste heat treatment furnace And the performance of the waste treatment apparatus can be fully exhibited.

  An outline of the waste treatment facility 1 to which the present invention is applied will be described with reference to FIG. Waste such as municipal waste is loaded on a truck and transported to a place where the waste treatment facility 1 is located. The waste treatment facility 1 has a large concrete pit 2, and the waste transported by a truck is put into the pit 2. The waste is crushed by a large rough crusher if necessary. The crushed waste is gripped / transferred by the large crane 3 and put into the dust supply hopper 4.

  A first dust supply device 5, which is a pusher type transfer means, is provided at the bottom of the dust supply hopper 4. A connection chute 6 is provided at the outlet end of the first dust supply device 5. At the lower end of the connection chute 6, a second dust supply device 7, which is a screw type transfer means, is provided. A passage extends downward from the tip of the second dust supply device 7 and is connected to the gasification furnace 8. In the gasification furnace 8, waste is partially burned, and the gasification furnace corresponds to a waste heat treatment furnace.

  The waste thrown into the dust supply hopper 4 moves to the first dust supply device 5, the connection chute 6, and the second dust supply device 7, and is supplied to the gasification furnace 8. The dust supply hopper 4, the first dust supply device 5, the connection chute 6, and the second dust supply device 7 constitute a waste supply device 24.

  The gasification furnace 8 includes a lower fluidized sand layer 9 and an upper freeboard 10. In order to form this fluidized sand layer 9, the primary combustion air is blown out from below to fluidize the sand as a fluidized medium that is a heat transfer means. In this fluidized sand layer 9, the waste is partially combusted and pyrolyzed while maintaining a high temperature of 550 to 650 ° C. to generate high-temperature combustible gas and solids such as fly ash and char.

  The combustible gas and the minute solid content that accompanies the combustible gas rise to the free board 10 side. Since the gas pipe 11 connects the free board 10 of the gasification furnace 8 and the ash melting furnace 12, the pyrolysis gas generated in the gasification furnace 8 and solid contents such as fly ash, char, etc. are connected to the gas pipe. It flows to the ash melting furnace 12 via.

  The ash melting furnace 12 includes a swirl chamber that swirls the gas from the gas pipe 11 in order to capture solid components such as fly ash. In the swirl chamber of the ash melting furnace 12, solid contents such as fly ash are melted at a high temperature of 1300 to 1500 ° C. by combustion of combustible gas, and the melt is scattered and adhered to the wall surface by centrifugal force due to the swirling of the gas.

  Since the lower part of the ash melting furnace is connected to the granulation pit 13, the melt attached to the wall surface of the swirl chamber falls and reaches the granulation pit 13 that stores water. The melt is solidified by being quenched with water. The solidified material is called slag, but is discharged to the outside by the conveyor 14.

  A secondary combustion chamber 15 is provided above the ash melting furnace 12. The gas rising from the ash melting furnace 12 is combusted in the secondary combustion chamber 15 by supplying secondary combustion air. Here, the heat of the combustion exhaust gas that has reached a high temperature is recovered by the boiler 16 downstream of the secondary combustion chamber 15.

  In the subsequent post-process, the exhaust gas passes through the first exhaust pipe 17 and passes through the temperature reducing tower 18, and the temperature is lowered. Next, slaked lime and activated carbon are sprayed on the exhaust gas in the second exhaust gas pipe 19 after passing through the temperature reducing tower 18, and an acidic gas such as hydrochloric acid or sulfur dioxide is converted into calcium chloride, calcium sulfate, or the like by a neutralization reaction. The dioxins are adsorbed on the activated carbon and collected by the dust collector 20.

  Next, the exhaust gas is discharged from the chimney 23 to the atmosphere after passing through the denitration catalytic reaction tower 21. Since these gas flows are produced by the suction blower 22 provided upstream of the chimney, the pressure from the gasification furnace to the catalytic reaction tower 21 is slightly lower than atmospheric pressure.

  If the waste supply device 24 is used, the supply speed of the waste to be supplied to the gasification furnace 8 is stabilized. Therefore, the operation of the process after the gasification furnace 8 is also stable, and the function of exhaust gas purification is easily exhibited. The exhaust gas to be discharged can be sufficiently purified.

  The waste supply device 24 will be described in more detail. The dust supply hopper 4 will be described with reference to FIGS. 3 and 4. The dust supply hopper 4 includes an upper portion 31 and a lower portion 32, and the height of each portion is about 4 m to 5 m. The upper portion 31 has a rectangular inlet 33 opened to the atmosphere at its upper end, three side surfaces are substantially vertical, and one side surface is an inclined surface of about 45 degrees. A bridge removing device 34 is provided on the side surface facing the inclined surface. The bridge removing device 34 includes a thin rectangular parallelepiped member 35 that moves up and down along the vertical plane by driving a hydraulic cylinder.

  The lower part of the dust supply hopper 4 extends downward while maintaining the space of the square section at the lower end of the upper part 31. The lower portion 32 has a steeper angle than the inclined surface of the upper portion 31, for example, approximately 80 degrees. Level detectors 36 and 37 are respectively installed on opposing wall surfaces at the joint of the upper portion 31 and the lower portion 32. When the level detectors 36 and 37 detect that there is no waste above the position of the level detectors 36 and 37, the crane 33 supplies the waste to the dust supply hopper 4.

  A bridge detector 38 is installed at a position slightly below the joint between the upper portion 31 and the lower portion 32. When the bridge detector 38 does not detect waste and the level detectors 36 and 37 detect waste, the waste bridges in the upper portion 31 of the dust supply hopper 4 and does not fall on the lower portion 32. Often, the bridge removal device 34 is driven to break the bridge and allow the waste to fall into the lower portion 32. The bottom of the dust supply hopper 4 is connected to the inlet 41 of the pusher-type dust supply device 5 through a connection port 39 that forms a rectangular space section.

  Next, the pusher-type dust supply device 5, the connection chute 6, and the screw-type dust supply device 7 will be described with reference to FIGS. The pusher-type dust supply device 5 has a rectangular parallelepiped-shaped feed ram 42 that spreads in the horizontal direction, a hydraulic cylinder 43 that slides the feed ram 42, and a movement of the feed ram 42 so as to support the feed drum 42 from the lower surface side of the feed ram 42. And a fee table 44 extending horizontally in the range. Here, two feed rams 42 and two hydraulic cylinders 43 have the same function in parallel.

  Further, the pusher-type dust supply device 5 includes a casing 45 that covers the feed ram 42 from the upper surface and the side surface. The casing 45 forms an outlet 46 at one end in the sliding direction of the inlet 41 and the feed ram 42 connected to the connection port 39 of the dust supply hopper 4. The upper and lower spaces between the casing 45 and the feed ram 42 have substantially the same size as the sectional space of the lower portion 32 of the dust supply hopper 4.

  A connection chute 6 is provided at the outlet 46 of the pusher dust supply device 5 so as to extend downward. The connection chute 6 includes an upper part 51 and a lower part 52. The upper part 51 forms a rectangular parallelepiped space extending horizontally in the outlet 46 space of the pusher type dust supply device 5.

  The lower part 52 forms a space in which the width direction becomes narrower toward the middle while the depth direction is constant. The lower end of the connection chute 6 is a rectangular outlet 54 that is slightly longer in the width direction than in the depth direction. Here, the depth direction refers to the sliding direction of the feed ram 42, and the width direction refers to a direction perpendicular to the sliding direction.

  A waste level sensor 53 is provided on the upper surface of the connection chute 6. When the level sensor 53 detects that the height of the waste in the connection chute 6 becomes a first predetermined level, for example, 1,000 mm or less, the pusher type dust supply device 5 is driven and the feed ram 42 is advanced. The waste accumulated in the dust supply hopper 4 is pushed out to the connection chute 6 side.

  When the waste level sensor 53 detects that the height of the waste in the connection chute 6 becomes a second predetermined level higher than the predetermined level, for example, 1700 mm, the feed ram 42 is retracted and discarded to the connection chute 6 side. Stop pushing things out. These processes are automatically controlled by a process control device.

  It is preferable to employ an ultrasonic method for the level sensor 53 because it can measure without contact with waste. Since many non-contact level sensors such as an ultrasonic type are sensitive to high temperatures, it is preferable to supply cooling air to the sensors.

  For this air, compressed air for instrumentation is suitable. The compressed air for instrumentation is usually about the same as room temperature, and is sufficiently lower than the heat resistance temperature of the level sensor 53. When the heat resistance temperature of the level sensor 53 is 80 ° C., a gas of 80 ° C. or more is present in the level sensor 53. In addition to preventing contact, it is also possible to expect an effect of cooling the rise of the temperature of the level sensor 53 due to radiant heat. Furthermore, since the lightly-compressed compressed air does not include foreign substances, the possibility of physical adverse effects on the level sensor 53 is low.

  The predetermined level of waste in the connection chute 6 has a meaning that the supply of waste to the second dust supply device 7 is not interrupted, and the high-temperature gas from the gasifier side is fed to the waste level sensor 53. It is preferable to set in consideration of the significance of making it difficult to reach.

  Based on the information of the waste level sensor 53, the driving degree of the pusher-type dust supply device 5 and the screw-type dust supply device 7 to be described below can be used without adopting means for automatically controlling the pusher-type dust supply device 5. By appropriately adjusting the transfer speed, waste can be deposited on the connection chute 6 within a predetermined range. However, the control based on the level sensor 53 is more reliable.

  Further, if the connecting chute 6 is filled with a large amount of waste, the compacted waste is supplied to the next process, and the screw-type dust supply device 7 to be described below also applies the pushing force of the screw. However, it is preferable to set the range of the amount of waste to be deposited on the connection chute 6 in consideration of this point as well.

  The outlet 54 at the lower part of the connection chute 6 is connected to the inlet 61 of the screw dust supply device. The screw-type dust supply device 7 includes two supply screws 62 arranged below the inlet 61 so that the axes are parallel to each other. The supply screw 62 is attached to the outer periphery of the rod or cylinder so as to wind a belt-like body in a spiral.

  A rod-type paddle 63 is provided between the supply screws 62. The rod-type paddle 63 is formed by projecting a plurality of rods along the circumferential direction at a constant pitch on the outer periphery of a rod-shaped or cylindrical shaft. The rod-type paddle 63 and the supply screw 62 are arranged so that their axes are parallel to each other.

  By means of a continuously variable transmission, a roller chain, a sprocket, etc., the rotation of the drive motor 64 is transmitted to the supply screw 62 and the rod-type paddle 63 while changing the rotation direction and rotation speed, and these are rotated. The supply screw 62 rotates toward each other, and the rod-type paddle 63 repeats forward and reverse rotation.

  Furthermore, the screw dust supply device 7 includes a casing 65. The casing 65 has an inlet 61 that covers both the supply screw 62 and the rod-type paddle 63 and is connected to the outlet 54 of the connection chute 6, and an outlet 66 at the tip of both the supply screw 62 and the rod-type paddle 63. Form.

  In steady operation, since a predetermined amount of waste is deposited on the connection chute 6 as described above, waste is always supplied to the inlet 61 of the screw dust supply device 7. This waste is wound into the screw groove of the supply screw 7 and sent to the outlet 66 side. In addition, large waste is shredded and transferred by crushing or tearing action by forward and reverse rotation of the rod-type paddle 7. As a result, the amount of discharge from the outlet of the solid matter containing large waste conveyed by the supply screw 62 becomes uniform, and the occurrence of fluctuations in the amount of discharge is alleviated.

  A passage 71 to the gasification furnace 8 is connected to the outlet of the screw dust supply device 7. Further, a slide gate 72 is provided on the outlet 66 side of the screw type dust supply device 7. When the waste supply device is stopped and waste gas from the gasifier is not supplied, the slide gate 72 is closed to cover the outlet. When waste is supplied, the slide gate 72 is opened and the outlet is opened. The screw-type dust supply device 7 is operated to supply waste to the gasification furnace.

  In order to prevent the inflow of combustible gas generated in the gasification furnace 8 from the dust supply hopper 4 and the inflow of air from the dust supply hopper 4 to the gasification furnace 8, a large amount of waste is deposited on the dust supply hopper 4. Yes. The pusher-type dust supply device 5 driven by the hydraulic cylinder 43 has a simple structure in which a large force can be easily exerted and troubles such as waste biting are unlikely to occur. Even waste generated can be easily discharged from the dust supply hopper 4.

  In the pusher type dust supply device 5, since the discharge of the waste is intermittent, a temporal fluctuation of the discharge amount occurs. Next, in a certain connection chute 6, a predetermined amount of waste is accumulated and the waste is supplied to the screw-type supply device 7, so that quantitative discharge with little temporal variation is possible.

  Further, by limiting the waste accumulated in the connection chute 6 to a predetermined range, the screw-type dust supply device 7 does not accumulate a large amount of waste, and the waste is excessively consolidated in the screw type dust supply device 7. It is possible to stabilize the discharge of waste so that no trouble occurs.

  In this way, by making the supply of waste to the gasification furnace 8 in a stable state with little temporal fluctuation, the combustion state of the gasification furnace 8 and further the exhaust gas treatment state as a subsequent process can be stabilized. , Sufficient performance can be exhibited.

Side cross-sectional schematic diagram of an embodiment of the present invention Front side cross-sectional schematic diagram of an embodiment of the present invention Side cross-sectional schematic diagram of an embodiment of the present invention Front side cross-sectional schematic diagram of an embodiment of the present invention Device configuration diagram of an embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Waste disposal equipment 2 Pit 3 Crane 4 Dust supply hopper 5 First dust supply device 6 Connection chute 7 Second dust supply device 8 Gasification furnace 9 Fluidized sand layer 10 Free board 11 Gas pipe 12 Ash melting furnace 13 Granulation pit 14 Conveyor 15 Secondary combustion chamber 16 Boiler 17 First exhaust gas pipe 18 Temperature reducing tower 19 Second exhaust gas pipe 20 Dust collector 21 Denitration catalyst reaction tower 22 Suction blower 23 Chimney 24 Waste supply device 25 Waste treatment device 31 Upper part 32 Lower part 33 Inlet 34 Bridge removing device 35 Rectangular member 36 Level detector 37 Level detector 38 Bridge detector 39 Connection port 41 Inlet 42 Feed ram 43 Hydraulic cylinder 44 Fee table 45 Casing 46 Outlet 51 Upper part 52 Lower part 53 Waste level Sensor 54 Outlet 61 Inlet 62 Supply screw 63 Rod type paddle 64 Drive Ta 65 casing 66 outlet 71 passage 72 sliding gate

Claims (3)

Connected to the outlet of the dust supply hopper in the waste supply apparatus that includes a dust supply hopper having an inlet opening for receiving waste at the top and having an outlet at the bottom, and transferring the waste accumulated in the dust supply hopper A pusher-type first dust supply device that has a formed inlet and pushes waste in a horizontal direction, a connection chute that has an upper portion connected to an outlet of the first dust supply device and that extends vertically, and the connection chute And a screw-type second dust supply device having an inlet connected to the lower part of the waste supply device. 2. The waste supply apparatus according to claim 1, wherein a level sensor that detects an accumulation amount of waste on the connection chute and a first dust supply if a detection level of the level sensor is lower than a first predetermined level. A control device for starting the transfer of the waste to the connection chute by the device and stopping the transfer of the waste by the first dust supply device if the detection level is a second predetermined level higher than the first predetermined level. A waste supply apparatus characterized by that. A waste processing apparatus comprising the waste supply apparatus according to claim 1 or 2, wherein a path for receiving waste pushed out from the second dust supply apparatus and discharging it to the waste heat treatment furnace, and the path A waste treatment apparatus comprising a waste heat treatment furnace for receiving and combusting wastes.

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