JP2006241354A - Waste gasifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize the supply of waste etc. by reducing the number of established supply units. <P>SOLUTION: This waste gasification unit comprises a supply means with which the waste is supplied in a vertical gasification furnace having a inlet 33 for the waste introduction at the upper part of the furnace, a gas supplying inlet to supply an oxidizing agent to the packed layer of the waste from downward, a gas outlet to discharge a produced gas from upward, and a discharging means to discharge the produced combustion residue from the bottom of the furnace. The supplying means is for supplying the waste and an additive in the inlet 33, and formed at the other end of the cylindrical casing 31 of which one end is connected to the inlet 33, has a supply inlet 7 through which the waste or additive is supplied, and herical blades 59 and 61 formed extending along the direction of a hollow shaft 37 which is supported in the casing 31 in coaxial direction to rotate freely, a first opening 67 which is formed on the outer surface opposite to the inlet of the hollow shaft 37, and a second opening 65 through which the additive is supplied on the inner side of the shaft 37 which extrudes gas tight from the end of the casing 31. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a waste gasifier that processes waste using a moving bed gasifier.

  Conventionally, as a method of treating municipal waste, industrial waste, sewage sludge, etc. (hereinafter simply referred to as waste), waste is introduced into a gasification furnace to form a packed bed, and an oxidant is supplied from the bottom of the furnace. A moving bed type gasification furnace has been proposed in which waste is gasified by partially burning and forming a combustion zone, a pyrolysis zone, and a drying zone in the furnace height direction (see Patent Document 1).

  In this moving bed type gasifier, in order to ensure the air permeability of the packed bed, it is usually filled with additives such as pumice (for example, non-combustible pellets) together with waste, and non-combustible flowing down through the combustion zone. The pellets are discharged from the lower part of the furnace together with the combustion residue and subjected to a separation process. Here, the waste and the non-combustible pellets are conveyed by different supply devices, for example, a screw conveyor or the like, and are supplied into the furnace from the upper part of the furnace.

Japanese Patent Laid-Open No. 2004-2552

  As described above, a plurality of supply devices are attached to the upper portion of the gasification furnace in accordance with wastes, additives, and the like supplied into the furnace. For this reason, the space for installing these is needed in the upper part of a gasification furnace, for example, there exists a problem that the design freedom of an apparatus is restrict | limited.

  On the other hand, in such a moving bed type gasifier, for example, when processing waste with high moisture content such as sludge, in order to secure a predetermined calorific value, high calorie waste with a large calorific value along with sludge ( For example, wood chips and the like are supplied into the furnace. In this case, for example, sludge and wood chips are conveyed by a screw conveyor or the like in a premixed state and supplied into the furnace.

  However, for example, when wastes having a large specific gravity difference are mixed and transported, such as sludge and wood chips, the wastes may be separated during transport. That is, if the waste is supplied into the furnace in a separated state, for example, there is a difference in the amount of heat generated in the horizontal section of the packed bed, and the temperature of the combustion zone may become uneven, leading to a reduction in gasification efficiency. There is.

  This invention makes it a subject to stabilize supply of waste etc. while reducing the number of installation of a supply apparatus.

  In order to achieve the above object, the present invention provides a vertical gasification furnace having an inlet into which waste is introduced at the top of the furnace, a supply means for supplying waste into the gasification furnace, and a gasification furnace A gas supply port for supplying oxidant from below to the packed bed of waste, a gas discharge port for discharging generated gas from above the gasification furnace, and a combustion residue generated by burning the waste at the bottom of the furnace The waste gasification apparatus having the discharge means for discharging from the waste water is provided with a supply means capable of simultaneously transporting different kinds of waste and the like.

  That is, the supply means of the present invention cuts waste and other wastes or additives to the inlet at the same time, specifically, a cylindrical casing having one end communicating with the inlet, A supply port formed at the other end of the casing for supplying waste or additives, a hollow shaft rotatably supported in a coaxial direction in the casing, and an axial direction on the outer peripheral surface and inner peripheral surface of the hollow shaft And a first opening formed on the outer surface facing the charging port of the hollow shaft, and another disposal on the inner surface side of the shaft protruding airtightly from the end surface of the casing And a second opening for supplying an object or an additive.

  According to this, with the rotation of the hollow shaft, for example, the waste is transported by the outer blades in the space between the inner surface of the casing and the outer surface of the shaft from the supply port, while the other waste is The space on the inner surface side of the hollow shaft is conveyed by the inner blade from the two openings. And since the waste conveyed through each space is discharged | emitted through the inlet of the gasification furnace used as a common discharge port, it is supplied in the gasification furnace in the state mixed in the predetermined ratio. . That is, according to the present invention, different types of wastes and additives can be stably supplied into the furnace by one supply device, so that the gasification efficiency of the waste is stabilized and the space is saved. Can be realized.

  ADVANTAGE OF THE INVENTION According to this invention, while reducing the number of installation of a supply apparatus, supply of waste etc. can be stabilized.

  Hereinafter, embodiments to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a block diagram showing a main part of a waste gasifier according to the present invention.

  As shown in FIG. 1, the waste gas apparatus of the present embodiment (hereinafter simply referred to as a gasifier 1) has a supply device 5 for supplying waste attached to the top of a cylindrical vertical furnace 3. Yes. The supply device 5 includes, for example, a first hopper 7 that stores waste in a state in which the waste is appropriately crushed and pulverized, and a second hopper that stores incombustible pellets that are mixed with waste in the furnace 3. A hopper 9 and a screw (described later) for transporting waste and incombustible pellets are provided. Double dampers (not shown) are provided at the inlets of the first hopper 7 and the second hopper 9, respectively. Waste and incombustible pellets are supplied into the furnace 3 by the supply device 5 through the insertion port 10.

  Next, the furnace 3 is formed with a discharge port 11 for discharging a generated gas (pyrolysis gas) on the top side wall, and a combustion oxidant gas (such as air or oxygen) and a water gasifying agent (water vapor) at the bottom. Etc.) is provided. The gasifying agent supply port 13 is formed, for example, at the tip of the rotary shaft of the rotary extractor 15 disposed at the bottom of the gasifier 1. In this case, the oxidant gas and water vapor that flow through the rotary shaft 17 and are supplied into the furnace from the gasifying agent supply port 13 are supplied radially into the gasification furnace 1. The rotary shaft 17 of the rotary extractor 15 is connected to a motor 21. When the rotary shaft 17 rotates, the rotary blade 16 cuts out the combustion residue of the waste in the radial direction and discharges it from the discharge port 19. Yes. The gasifying agent supply port 13 is not limited to the present embodiment as long as the oxidizing agent and water vapor are uniformly supplied in the horizontal cross-sectional direction of the furnace 3.

  A plurality of temperature sensors 23 are attached to the furnace 3 at predetermined intervals in the furnace height direction of the furnace wall. A plurality of level sensors 25 for detecting the height of the packed bed are attached in the furnace height direction to the furnace wall above the temperature sensor 23 arranged at the uppermost stage. Although not shown, a pressure sensor for detecting the pressure in the upper space 27 of the packed bed is attached to the furnace wall above the level sensor 25.

  Next, a detailed configuration of the supply device 5 will be described. 2 is a configuration diagram of a supply device 5 of a waste gasifier to which the present invention is applied. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, and FIG. 4 is a cross-sectional view taken along line BB in FIG. FIG.

  As shown in FIG. 2, the supply device 5 of the present embodiment includes a mixing charging chute 33 connected to a lower portion on one end side of a cylindrical casing 31 and a first hopper 7 connected to an upper portion on the other end side. In the casing 31, a hollow shaft 37 whose axis is coaxial is rotatably supported. At both ends of the casing 31, a head plate 39 is provided on the discharge side (left side in the drawing) of the supply device 5, and an end plate 41 is provided on the supply side, and the holding bracket is coaxially connected to the discharge side end of the shaft 37. 43 is supported by a bearing 45 via a head plate 39. On the other hand, the supply side of the shaft 37 protrudes through the end plate 41, and a holding fitting 47 that is coaxially connected to an end portion of the protruding shaft 37 is supported by a bearing 49. Here, the end of the holding metal fitting 47 protrudes outward from the bearing 49, the sprocket wheel 51 is fixed to the end, and is connected to the rotating shaft of the drive motor 55 via the chain 53. For example, a gland packing or the like is formed in an airtight manner at a boundary portion between the head plate 39 and the holding metal fitting 43, a boundary portion between the end plate 41 and the shaft 37, or the like.

  The shaft 37 has a spiral inner blade 59 formed in the axial direction of the inner peripheral surface, and a spiral outer blade 61 formed in the axial direction of the outer peripheral surface. And the outer blade | wing 61 is not formed in the shaft 37 which protrudes outside from the end plate 41 of the casing 31, and only the inner blade | wing 59 is formed. The protruding end portion of the shaft 37 is hermetically covered by the second hopper 9, and the outer peripheral surface of the shaft 37 extends in a direction substantially perpendicular to the axis of the shaft 37, that is, in a vertical direction. An opening 65 is formed at a position facing the supply path of the second hopper 9. On the other hand, an opening 67 is formed on the outer peripheral surface of the shaft 37 at a position facing the mixing charging chute 33.

  In the second hopper supply furnace, for example, when handling waste or the like that is unlikely to drop by its own weight, it is preferable to provide a push-in bar 54 having rotating blades 52 around the rotation axis as shown in FIG. . The push bar 54 has a rotating shaft that is rotated by a driving motor (not shown), and can push incombustible pellets supplied from the second hopper 9 toward the opening 65 by the rotary blade 52.

  Next, the operation of this embodiment will be described. First, when the drive motor 55 is driven to rotate the shaft 37 of the supply device 5, waste is cut out from the first hopper 7, and this waste is removed between the outer surface of the shaft 37 and the inner surface of the casing 31. This space is conveyed to the discharge side by the outer blade 61. Further, the non-combustible pellets stored in the second hopper 9 are taken into the shaft 37 when the opening 65 is in a position facing the supply path of the second hopper 9 by the rotation of the shaft 37, that is, upward. It is conveyed to the discharge side by the inner blade 59. Here, when handling waste or the like that cannot be supplied to the opening 65 due to its own weight drop, the pushing bar 54 is used to push the opening 65 into the opening 65 by an external force. Subsequently, the non-combustible pellets transported in the shaft 37 are discharged from the opening 67 when the opening 67 faces the mixing and charging chute 33 by the rotation of the shaft 37, that is, downward.

  As described above, the waste and the non-combustible pellets respectively conveyed by the outer blade 61 and the inner blade 59 are mixed in a predetermined ratio in the mixing and charging chute 33 and supplied into the furnace 3.

  The waste and incombustible pellets supplied into the furnace 3 are uniformly filled into the furnace 3 from the bottom to form a packed bed. Here, the non-combustible pellets are for improving the flowability of an oxidant or the like supplied into the furnace 3, for example.

  In this way, the oxidant is supplied from the gasifying agent supply port 13 to the packed bed filled with waste, and high temperature air (for example, 400 ° C. or more) is blown from the ignition hot air generator 14 to ignite. . Then, the supply amount of the oxidant is adjusted, the waste is partially burned, and a combustion zone is formed in the packed bed. The pyrolysis gas generated by pyrolyzing the waste at the furnace bottom and the upper layer of the furnace bottom by the combustion heat in the combustion zone rises in the furnace 3 through the gap between the waste and is discharged from the discharge port 11. The

In a steady state where the partial combustion and thermal decomposition of the waste are stable, a stable combustion zone 71 is formed in the vicinity of the bottom of the furnace, a thermal decomposition zone 73 is formed in the upper part, and the waste is dried in the upper part. A band 75 is formed. For example, when the waste reaches about 300 ° C. or more, it is thermally decomposed, and therefore, the region of the packed bed of waste exceeding the temperature range becomes the thermal decomposition zone 73. In the pyrolysis zone 73, the waste is pyrolyzed to generate combustible pyrolysis gas and carbon (char). The char generated here flows down to the combustion zone 71 and burns, and the temperature of the combustion zone becomes about 1000 ° C. or higher. Further, a part of the char generated in the thermal decomposition zone 73 reacts with the aqueous gasifying agent supplied from the gasifying agent supply port 13 to generate CO and H ₂ . The flow rates of the oxidizing agent and the water gasifying agent supplied from the gasifying agent supply port 13 are adjusted so that most of the generated char becomes combustion gas and water gas.

  The generated gas obtained by mixing the pyrolysis gas and the water gas generated in this manner passes through the drying zone 75 and dries the waste in the process of flowing through the gap between the wastes in the upper layer. The product gas is reduced in temperature (for example, about 200 ° C.) by drying the waste, and is discharged from the discharge port 11 through the upper space 27 formed at the top of the furnace 3. In addition, even if fly ash generated in the combustion zone 71 is accompanied by the product gas, the waste layer filled in the dry zone 75 is collected as a filter and the fly ash flowing out from the discharge port 11 is collected. The amount can be reduced. The generated gas discharged from the discharge port 11 is cleaned by various treatments such as desalting and dust removal on the downstream side, and then stored in a gas holder (not shown) or the like, for example, as a fuel for a gas engine or the like. Used as

  On the other hand, the waste dried in the drying zone 75 gradually moves to the thermal decomposition zone 73 and undergoes thermal decomposition treatment, and then moves to the combustion zone 71 to be pyrolyzed and burned to become ash. These flow down the cooling zone 77 formed in the lower layer of the combustion zone 71, and are cut out to the discharge port 19 by the rotation of the rotary extractor 15 and discharged outside the furnace. Ashes, incombustibles, incombustible pellets, etc. discharged outside the furnace are separated, and the incombustible pellets are reused.

  As described above, according to the present embodiment, the waste and the non-combustible pellets are transported through separate paths by the inner blade 59 and the outer blade 61 formed on the shaft 37 of the supply device 5, and are mixed and charged in common. Since it is supplied into the furnace 3 through the chute 33, it is supplied into the furnace 3 in a state of being mixed at a predetermined ratio and is uniformly filled in the packed bed. Therefore, in the gasifier 1, for example, the gasification efficiency of waste can be stabilized, and space saving can be realized by reducing the number of installed supply devices 5.

  Moreover, although this embodiment demonstrated the example which supplies a waste material and an incombustible pellet with the supply apparatus 5, it is not limited to this, For example, wood waste and sludge, general waste and sludge, general waste and wood waste, etc. It can also be applied to combinations of different types of waste. And according to the supply apparatus 5, when supplying wastes with such a large specific gravity difference, for example, since it is not necessary to mix in advance, a mixing apparatus etc. can be abbreviate | omitted. Moreover, since separation at the time of conveying such a mixture of wastes can be avoided, wastes can be supplied stably.

  Needless to say, the supply device 5 of the present embodiment is not limited to a moving bed type gasifier, and can be applied to other waste treatment devices and the like.

It is a block diagram which shows the principal part of the waste gasification apparatus which concerns on this invention. It is a block diagram of the supply apparatus of the waste gasification apparatus which concerns on this invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gasifier 3 Furnace 5 Supply apparatus 7 1st hopper 9 2nd hopper 10 Input port 11 Discharge port 13 Gasification agent supply port 19 Discharge port 31 Casing 33 Mixing input chute 37 Shaft 59 Inner blade 61 Outer blade 65, 67 opening

Claims (1)

A vertical gasification furnace having an inlet into which waste is introduced at the top of the furnace, supply means for supplying the waste into the gasification furnace, and a packed bed of the waste in the gasification furnace A gas supply port for supplying an oxidant from below, a gas discharge port for discharging generated gas from above the gasification furnace, and discharge means for discharging combustion residues generated by burning the waste from the bottom of the furnace In a waste gasifier equipped with
The supply means supplies the waste and other wastes or additives to the input port, and is formed at a cylindrical casing having one end communicating with the input port and the other end of the casing. A supply port for supplying the waste or the additive, a hollow shaft rotatably supported in the casing in the coaxial direction, and an axially extending outer peripheral surface and an inner peripheral surface of the hollow shaft A spiral blade formed as a result, a first opening formed on the outer surface of the hollow shaft facing the charging port, and the other inner surface of the shaft projecting airtightly from an end surface of the casing. A waste gasifier having a second opening for supplying waste or the additive.

Images