JP2008249212A - Waste thermal decomposition gasification method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To take out a thermally-decomposed gas of small moisture content by performing direct contact drying and indirect heating thermal decomposition of waste in one kiln. <P>SOLUTION: A front part at an inlet 2 side of an external heating kiln furnace is applied as a drying zone I, and a rear part at an outlet 3 side of the external heating kiln furnace 1 is applied as a thermal decomposition zone II. In the drying zone I, an outer peripheral portion is composed of a cylindrical perforated plate portion 21, and a combustion exhaust gas 11a after circulating a high-temperature gas 11 in a heating flow channel 10 outside of the thermal decomposition zone II to be used as a heat source in indirect-heating heat exchange, is sucked to the drying zone I from holes 22 of the perforated plate portion 21. The waste is dried by direct contact with the combustion exhaust gas 11a in the drying zone I, and the dry exhaust 11b including much moisture is taken out. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a waste pyrolysis gasification method and apparatus for pyrolyzing and gasifying waste such as municipal waste.

  Conventionally, an incineration system in which waste is burned in an incinerator has been adopted as a waste treatment system. However, there is a problem of dioxin generation in the combustion exhaust gas, and there is a large amount of gas and heat. Problems such as poor energy use efficiency, a large amount of ash, which is difficult to process, and landfill capacity is approaching its limit.

  Therefore, as a next-generation waste treatment system, waste is heated and pyrolyzed in an inert atmosphere, and the generated pyrolysis gas and pyrolysis residue (carbon and ash) are reduced in the combustion / melting furnace. A gasification and melting method has been developed in which the ash content in the waste is taken out as molten slag by burning it at a high temperature. The pyrolysis gasification method is also used for the purpose of converting waste into carbonized fuel. In such a system, an external heat kiln system is adopted in order to thermally decompose and gasify the waste, and the waste is indirectly heated and dried by heat from the outside to be thermally decomposed.

  FIG. 5 shows an outline of an example of a pyrolysis gasification apparatus used for pyrolyzing and gasifying waste as described above, and the outlet 3 side of the other end is more than the inlet 2 side of one end. A screw conveyor 4 is provided at the inlet 2 at one end in the longitudinal direction of the rotary type external heat kiln furnace 1 that is inclined sideways so as to be lowered by 3 degrees, and the waste 6 is input from the input hopper 5. is there. The outlet 3 at the other end in the longitudinal direction of the external heat kiln furnace 1 is provided with a separation chamber 9 for separating the pyrolysis gas 7 and the pyrolysis residue 8, and the external heat kiln furnace 1 is rotated at a low speed. In FIG. 3, while the waste 6 introduced from the inside of the input hopper 5 is gradually supplied into the external heat kiln furnace 1 by the screw conveyor 4, the inside of the outer heating flow path 10 is directed from the outlet 3 side toward the inlet 2 side. By circulating the high temperature gas 11, the waste 6 in the external heat kiln furnace 1 is heated and dried to be thermally decomposed. The pyrolysis gas 7 generated by pyrolysis in the external heat kiln furnace 1 is taken out from the upper part of the separation chamber 9 and sent to the downstream combustion / melting furnace, while the pyrolysis residue 8 is separated from the separation chamber 9. The incombustible material is once taken out from the lower part and collected, and then sent to the downstream combustion / melting furnace.

  In the above pyrolysis gasifier, the pyrolysis residue 8 generated by the pyrolysis in the external heat kiln furnace 1 needs to be once taken out from the lower part of the separation chamber 9 to separate and collect incombustible materials such as aluminum and iron. Therefore, the temperature of the high temperature gas 11 introduced into the heating flow path 10 of the external heat kiln furnace 1 is, for example, about 550 ° C. so as to be equal to or lower than the melting point of aluminum, while the pyrolysis gas 7 is The temperature is set to about 450 ° C. so that it can be sent to a subsequent process.

  However, waste such as municipal waste generally contains about 30 to 40% of water. When these are pyrolyzed and taken out for fuel, they are greatly affected by the moisture concentration.

  That is, first, when the moisture contained in the waste is evaporated by drying in an external heat kiln furnace, a large amount of heat is required to evaporate the moisture, and the amount of heat necessary for evaporation and temperature rise of the moisture is It is large and occupies nearly two-thirds of the amount of heat required for the whole, and the remaining amount of heat raises the solid content and performs thermal decomposition.

  In addition, if moisture (water vapor) evaporated during drying of the waste is contained in the pyrolysis gas, the deterioration of the properties of the pyrolysis gas becomes a low calorie gas. This tendency becomes more remarkable as the moisture concentration is higher.

  Therefore, in the pyrolysis gasification treatment of waste, the amount of heat required for evaporating the moisture contained in the waste is reduced, and the evaporated moisture is not included in the pyrolysis gas as water vapor. Thus, it is required to be able to take out a high calorie pyrolysis gas.

  As a response to such a requirement, there has been proposed a pyrolysis gas that is removed from the outlet side of the external heat kiln furnace by removing moisture in the previous stage and is a high calorie gas with little moisture.

  As an example, FIG. 6 shows an example in which drying and thermal decomposition are performed by external heat in an external heat kiln furnace so that a pyrolysis gas with a small amount of water is taken out from the rear stage. That is, in the external heat kiln furnace (pyrolysis furnace) 1 having one end in the longitudinal direction as the inlet 2 and the other end as the outlet 3, the waste 6 supplied from the inlet 2 is indirectly heated to thermally decompose. In the waste pyrolysis gasifier, the external heat kiln furnace 1 is divided into a front part 1a on the inlet 2 side and a rear part 1b on the outlet 3 side, and the external heat kiln A gas extraction line 12 for taking out the pyrolysis gas 7a generated in the front stage 1a is connected to the inlet 2 part of the furnace 1 and generated in the rear stage 1b at the outlet 3 part of the external heat kiln furnace 1. A gas extraction line 13 for extracting the pyrolysis gas 7b is connected.

  Other configurations are the same as those shown in FIG. 5, and the same components are denoted by the same reference numerals. Thus, most of the pyrolysis gas 7a generated in the front stage 1a in the external heat kiln furnace 1 is prevented from flowing into the rear stage 1b, and the pyrolysis gas 7a having a large amount of moisture generated in the front stage 1a is introduced into the inlet 2. It is possible to take out the pyrolysis gas 7b with less water generated in the rear stage part 1b as a high calorie gas from the outlet 3 part, and take out the high calorie gas as a heat source that requires a high temperature. Can be used widely (see, for example, Patent Document 1).

  FIG. 7 shows another example. The waste 6 supplied to the inside is dried and pyrolyzed using the high temperature gas 11 generated in the hot air generating furnace 14 as a heat source, and the pyrolysis gas 7 and the pyrolysis residue 8 are obtained. A ventilation dryer 15 for drying the waste 6 before being supplied to the external heat kiln furnace 1 is installed on the upstream side of the external heat kiln furnace 1, and the ventilation dryer 15 A combustion exhaust gas line 16 is connected so that the combustion exhaust gas 11a after being used for heating the external heat kiln furnace 1 can be introduced and used as a heat source for the ventilation dryer 15, and the combustion exhaust gas 11a from the external heat kiln furnace 1 is connected. Is introduced into the ventilation dryer 15 so as to be brought into direct contact with the waste 6. In the ventilation dryer 15, the waste 6 is dried to remove moisture of 50% or more, and the waste 6 after drying is supplied into the external heat kiln furnace 1. In the external heat kiln furnace 1, The waste 6 supplied after drying is indirectly heated and pyrolyzed by a high-temperature gas 11 circulated through the heating flow path 10 to generate a pyrolysis gas 7 and a pyrolysis residue 8. As a result, the moisture contained in the waste 6 is dried and blown off by the ventilation dryer 15, and the waste 6 having a low moisture content is pyrolyzed and gasified in the external heat kiln furnace 1. It is supposed that the calorie of the cracked gas 7 can be increased (for example, see Patent Document 2).

JP-A-10-132238 JP 11-141834 A

  In what is described in the above patent document, the pyrolysis gas containing a large amount of moisture generated at the front stage of the external heat kiln furnace can be taken out through the gas extraction line at the inlet, so it was generated at the front stage. Since most of the pyrolysis gas does not flow into the rear stage, it has the advantage of being able to take out the high-calorie pyrolysis gas with less water generated in the rear stage, but drying is also indirectly heated. Therefore, there is no idea or suggestion of drying by a direct contact method in the front part.

  In this regard, what is described in Patent Document 2 is that a direct contact type dryer is placed separately to separate the drying of the waste, and the moisture is evaporated by drying to some extent in advance, and the rest is an indirect heating method. It is one that is pyrolyzed in an external heat kiln furnace, and it is possible to increase the calorie of the pyrolysis gas, which is effective, but requires two units of the external heat kiln furnace 1 and the ventilation dryer 15, The number of facilities including incidental facilities is increasing.

  Therefore, the present invention is similar to that described in Patent Document 2 in one kiln furnace in order to simplify the facility while taking advantage of the advantages described in Patent Document 1 and Patent Document 2 above. It is intended to provide a waste pyrolysis gasification method and apparatus that can perform drying by direct contact method and pyrolysis by indirect heating method at the same time, and can take out dry exhaust gas and pyrolysis gas separately. is there.

  In order to solve the above-mentioned problems, the present invention is designed to thermally decompose waste supplied from the inlet side by indirect heating with a high-temperature gas, with one end side in the longitudinal direction as an inlet and the other end side as an outlet. The exhaust gas after being used as a heat source for indirect heating and pyrolysis is directly blown into the furnace at the front stage on the inlet side of the thermal kiln furnace, and the waste gas is brought into direct contact with the waste exhaust gas and waste. The combustion waste gas containing a lot of moisture is taken out from the inlet side, and then the dried waste is subjected to indirect thermal pyrolysis with high-temperature gas at the rear stage on the outlet side of the external heat kiln furnace. And a waste pyrolysis gasification method characterized in that the generated pyrolyzed gas with less water content is taken out from the outlet side, and one end side in the longitudinal direction is used as an inlet and the other end side is used as an outlet. The external heat kiln furnace, which is designed to thermally decompose waste supplied from the side by indirect heating with a high-temperature gas, is divided into a front part on the inlet side and a rear part on the outlet side, and the front part on the inlet side is A pyrolysis zone in which gas can be blown into the furnace from the outer periphery to dry the waste by direct contact, and the rear stage on the outlet side is thermally decomposed by indirect heating with high-temperature gas The waste dried at the front stage is pyrolyzed at the rear stage so that a gas with a high water content is taken out from the inlet side and a pyrolytic gas with a low water content is taken out from the outlet side. A waste pyrolysis gasifier characterized by

  Further, in the above configuration, the combustion exhaust gas after using the high temperature gas as a heat source for indirect heating pyrolysis at the rear stage part on the outlet side of the external heat kiln furnace has a large number of holes in the front part on the inlet side of the external heat kiln furnace. The waste is blown directly into the furnace from the outer periphery, and the waste is directly contact-dried.

  Further, the gas is blown into the drying zone through a cylindrical perforated plate portion or a cylindrically arranged aeration tube.

  Furthermore, in the above configuration, lifters are provided in the drying zone at a necessary interval in the circumferential direction, or a weir is provided at the boundary between the drying zone and the thermal decomposition zone.

According to the waste pyrolysis gasification method and apparatus of the present invention, the waste supplied from the inlet side is pyrolyzed by indirect heating with a high-temperature gas, with one end side in the longitudinal direction as the inlet and the other end as the outlet. The combustion exhaust gas after being used as a heat source for indirect thermal pyrolysis is directly blown into the furnace at the front stage on the inlet side of the external heat kiln furnace. In order to dry the waste and to remove the flue gas containing a lot of moisture from the inlet side, the dried waste is then indirectly infused with high-temperature gas at the rear stage which is the outlet side of the external heat kiln furnace. A waste pyrolysis gasification method characterized in that pyrolysis gas produced by heating and pyrolysis is extracted from the outlet side with a low moisture content, and one end side in the longitudinal direction is taken as an inlet and the other end side is taken out. The external heat kiln furnace in which waste supplied from the inlet side is thermally decomposed by indirect heating with a high-temperature gas is divided into a front stage part on the inlet side and a rear stage part on the outlet side. The part is made into a drying zone in which gas can be blown from the outer periphery into the furnace to dry the waste by direct contact, and the latter part on the outlet side is thermally decomposed by indirect heating with high-temperature gas. A structure in which a waste gas dried at the front stage is pyrolyzed at the rear stage so that a gas with a high water content is taken out from the inlet side and a pyrolytic gas with a low water content is taken out from the outlet side. In addition, the waste pyrolysis gasifier is characterized in that the combustion exhaust gas after using the high-temperature gas as a heat source for indirect heating pyrolysis at the rear stage of the outlet side of the external heat kiln furnace is used as external heat. Ki The waste is directly contacted and dried by blowing it into the furnace from the outer periphery through a large number of holes at the front part on the inlet side of the furnace, and the cylindrical perforated plate part is blown into the outer periphery of the drying zone. Since this is performed by using an air diffuser or by using an air diffuser, the following excellent effects can be obtained.
(1) Indirect heat pyrolysis and direct contact drying can be carried out in one kiln, and this makes it possible to reduce the size of the entire kiln without increasing the number of equipment.
(2) A gas containing a large amount of water by direct contact drying at the front part of the external heat kiln furnace and a pyrolysis gas having a low water content can be separately taken out from the dried waste by indirect heating pyrolysis at the rear part. It is possible to easily take out a high-calorie pyrolysis gas with little moisture.
(3) A high-temperature combustion gas can be obtained by burning the high-quality (low moisture and high calorie) pyrolysis gas extracted in (2) above. By using this high-temperature combustion gas as a heat source for indirect heating pyrolysis, the heat source for pyrolysis and drying can be supplied by itself.
(4) The pyrolysis gas is good in quality as described above, and can be burned at a low air ratio, so there is little residual oxygen, and because of the combustion gas of the gas component taken out by pyrolysis at low temperature It contains almost no ash containing molten salt. Therefore, the kiln drying stage and the normal combustion inside the kiln can be substantially suppressed. As a result, the high temperature corrosiveness is low compared to ordinary incineration exhaust gas. Therefore, it is necessary to use special steel as the kiln material by setting the temperature of the gas containing a large amount of moisture to be taken out from the drying zone to 150 ° C or higher. Sex can be lost.
(5) By adopting a configuration in which the lifters are arranged in the drying zone at a necessary interval in the circumferential direction, the operation in which the waste is lifted and dropped by the lifter can be repeated, and the contact effect with the combustion exhaust gas is further improved. Can be increased.
(6) By providing the weir near the boundary between the drying zone and the pyrolysis zone, the residence time of the waste in the drying zone can be adjusted, and the waste drying effect can be improved.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  1 (a) and 1 (b) show an embodiment of the present invention. Like the conventional waste pyrolysis gasifier shown in FIG. 5, the outlet at the other end rather than the inlet 2 side at one end. The screw conveyor 4 is provided at the inlet 2 at one end in the longitudinal direction of the rotary type external heat kiln furnace 1 that is inclined sideways so that the 3 side is lowered by about 3 degrees, and the waste 6 is input from the input hopper 5. In addition, a separation chamber 9 for separating the pyrolysis gas 7 (see FIG. 5) and the pyrolysis residue 8 is provided at the outlet 3 at the other longitudinal end of the external heat kiln furnace 1. In the external heat kiln furnace 1 from the inlet 2 by indirect heating by the high temperature gas 11 flowing through the heating flow path 10 so that the high temperature gas 11 is supplied to the heating flow path 10 outside the thermal kiln furnace 1 from the outlet 3 side. In a configuration in which the waste 6 supplied to is thermally decomposed, The external heat kiln furnace 1 is divided into a front part on the inlet 2 side and a rear part on the outlet 3 side. The front part is a drying zone I and the rear part is a pyrolysis zone II. After the indirect heating is finished, the combustion exhaust gas 11a flowing through the heating flow path 10 is brought into direct contact with the waste 6.

  More specifically, the external heat kiln furnace 1 is configured so that the inner cylinder 1a and the outer cylinder 1b are concentrically arranged with a necessary gap therebetween and can be rotated integrally, and is supplied into the inner cylinder 1a. The waste 6 is indirectly heated and thermally decomposed by a high-temperature gas 11 flowing through an annular heating channel 10 formed between the inner cylinder 1a and the outer cylinder 1b, and used for thermal decomposition. The high-temperature exhaust gas 11a is taken out from the gas extraction box 17 on the inlet side. A high temperature gas introduction box 18 is provided at the outlet 3 of the external heat kiln furnace 1, and the high temperature gas 11 obtained by burning a part of the pyrolysis gas in the hot air generation furnace 14 is supplied to the high temperature gas introduction box 18. It is made to supply and distribute | circulate through the said heating flow path 10. For this reason, the external heat kiln furnace 1 rotates between the gas extraction box 17 on the inlet side and the high-temperature gas introduction box 18 on the outlet side via the rotary joint 19 and the rotary seal plate 20.

  The external heat kiln furnace 1 has a front stage on the inlet 2 side as a drying zone I and a rear stage on the outlet 3 side in a pyrolysis zone II, and is directly contacted by high-temperature combustion exhaust gas 11a in one kiln furnace. Drying and indirect heating pyrolysis with the hot gas 11 can be performed simultaneously.

  The drying zone I on the inlet 2 side of the external heat kiln furnace 1 has a part of the inner cylinder 1a, that is, a region in a range of a required length closer to the center from the end of the inner cylinder 1a on the inlet 2 side. A cylindrical perforated plate portion 21 having perforations is formed, and the flue gas 11a is directly introduced (injected) from the outside to the inside through each hole 22 of the perforated plate portion 21, that is, into the external heat kiln furnace 1. The waste 6 supplied to the drying zone I is brought into direct contact with the waste 6 so that the waste 6 can be dried by direct contact between the waste 6 and the combustion exhaust gas 11a.

  The combustion exhaust gas 11a used for drying the waste 6 in direct contact with the waste 6 in the drying zone I is used as a dry exhaust 11b between the inlet 2 side end of the inner cylinder 1a and the inner cylinder 1a and the outer cylinder 1b. As shown by the arrows from the end portion on the inlet 2 side, the gas extraction box 17 is reached, from which it can be extracted through the gas extraction line 17a.

  On the other hand, the thermal decomposition zone II at the rear stage on the outlet 3 side of the external heat kiln furnace 1 is indirectly heated and thermally decomposed by the high-temperature gas 11 circulated through the outer heating channel 10 from the outlet 3 side to the inlet 2 side. The action is performed, and the waste 6 after being dried in the drying zone I is thermally decomposed so that a pyrolysis gas 7A with less moisture is generated.

  In addition, the dry exhaust 11b which dries the waste 6 in the drying zone I and is taken out from the gas take-out box 17 through the gas take-out line 17a needs to be taken out at 150 ° C. or higher where low-temperature corrosion does not occur. Accordingly, the size of the drying zone I, the residence time of the waste 6 and the like are directly contacted with the waste gas 6 from the combustion exhaust gas 11a which has been used as a heat source for indirect heating and pyrolysis in the thermal decomposition zone II and becomes about 350 ° C. It is determined that it can be taken out at 150 ° C. or higher after being dried and the waste 6 can be efficiently dried.

  Reference numeral 23 is an induction fan provided in the gas extraction line 17a, 24 is a pyrolysis gas extraction line, and other configurations are the same as those in the waste pyrolysis gasification apparatus shown in FIGS. Are given the same reference numerals.

  In addition, the treatment of the pyrolysis gas 7A and the pyrolysis residue 8 generated in the pyrolysis zone II is the same as that shown in FIG.

  Because of the above configuration, the waste 6 in the charging hopper 5 is supplied to the drying zone I of the external heat kiln furnace 1 by the screw conveyor 4 and is supplied to the high temperature gas introduction box 18 on the outlet 3 side of the external heat kiln furnace 1. For example, when the high-temperature gas 11 at about 550 ° C. is introduced and circulated in the heating channel 10 from the outlet 3 side to the inlet 2 side, the waste pyrolysis gasification apparatus of the present invention is operated. In the state where the waste 6 has not yet reached the outlet 3 side of the external heat kiln furnace 1 at the beginning of operation, the pyrolysis of the waste 6 in the pyrolysis zone II is not performed, but the heating channel 10 When the high-temperature gas that has been passed through the interior to the inlet 2 side and passed through the pyrolysis zone II reaches the drying zone I, the inner cylinder 1a has a large number of holes 22 in the perforated plate portion 21 as indicated by arrows. Inside, that is, blown into the furnace Thus, the waste 6 is directly contacted.

  The waste 6 in the drying zone I contains moisture, but it is lifted in the rotating direction by the perforated plate portion 21 of the drying zone I along with the rotation of the external heat kiln furnace 1 and then dropped beyond the angle of repose. By repeating the above, it is uniformly brought into contact with a high-temperature gas, and water is gradually evaporated and dried to some extent. Since the external heat kiln furnace 1 is placed horizontally such that the outlet 3 side is lower than the inlet 2 side, the waste 6 dried to some extent in the drying zone I is agitated by the rotation of the external heat kiln furnace 1. While being moved, it is moved to the outlet 3 side and gradually moved from the drying zone I into the thermal decomposition zone II.

  The dried waste 6 transferred to the pyrolysis zone II of the external heat kiln furnace 1 is circulated through the heating channel 10 outside the pyrolysis zone II from the outlet 3 side to the inlet 2 side. Is heated indirectly by the hot gas 11. Thereby, the waste 6 in the thermal decomposition zone II is thermally decomposed by external heat, and the pyrolysis gas 7A and the thermal decomposition residue 8 are produced | generated. Since pyrolysis gas 7A has less moisture in waste 6 supplied to pyrolysis zone II, the amount of moisture evaporated during the pyrolysis process is small. As from the pyrolysis gas take-out line 24 at 400 to 450 ° C.

  After being used for indirect heating to the waste 6 in the pyrolysis zone II, the combustion exhaust gas 11a cooled to 350 ° C. is blown into the inner cylinder 1a through the holes 22 of the porous plate portion 21 in the drying zone I, As described above, the waste 6 is brought into direct contact with the waste 6 to be dried.

  The dry exhaust 11b after directly contacting the waste 6 in the drying zone I and used for drying the waste 6 contains a large amount of moisture in the drying of the waste 6, and is in the middle of the gas extraction line 17a. By being drawn by the provided induction fan 23, it is taken out from the drying zone I to the gas take-out box 17 as indicated by an arrow, and further taken out from here through the gas take-out line 17a. The dry exhaust gas 11b containing a large amount of water taken out from the gas extraction line 17a is led to an exhaust gas outlet of a combustion / melting furnace similar to that shown in FIG. When mixed with molten exhaust gas, it is decomposed at high temperature and discharged as a gas at 800 ° C. or higher.

  Further, the high-temperature gas 11 of about 550 ° C. used as a heat source for indirect heating pyrolysis in the pyrolysis zone II and direct contact drying in the drying zone I is used for the moisture generated by the pyrolysis in the pyrolysis zone II. A small amount of high-calorie pyrolysis gas 7A is branched from a pyrolysis gas take-out line 24 that leads to a combustion / melting furnace (not shown) on the downstream side, and a part of the pyrolysis gas 7A is recovered. It is used for combustion with properties close to an inert gas of 5% or less of residual oxygen burned in the generator 14 at an air ratio of 1.3 or less. Thereby, the thermal decomposition of the waste by self-heating and the drying of the waste can be enabled.

  In the above, in the case of waste such as municipal waste, the properties of the object to be treated vary depending on the amount of water contained, but this property change is basically handled by adjusting the amount of gas supplied. However, it is possible to adjust the supply amount of the processing object or adjust the temperature.

  Next, a lifter having a required height is attached in the drying zone I of the external heat kiln furnace 1 at a required interval in the circumferential direction so as to enhance the stirring effect of the waste 6 in the drying zone I. be able to.

  That is, as shown by a two-dot chain line in FIG. 1B, a plurality of, for example, four lifters 25 as shown in the figure are provided on the inner surface of the porous plate portion 21 in the drying zone I. And are attached radially at substantially equal intervals in the circumferential direction so as to project the required amount inward.

  According to this embodiment, when the external heat kiln furnace 1 rotates, the waste 6 supplied to the drying zone I is received by the lifter 25 by the rotation of the lifter 25 and the lifted waste 6 is lifted. As a result, the waste is agitated sequentially by the lifters 25.

  This makes it possible to improve the efficiency of direct contact with the combustion exhaust gas 11a at 350 ° C. after being used as a heat source for indirect heating pyrolysis of the waste 6 in the thermal decomposition zone II, and more due to more efficient drying. The water can be taken out.

  FIG. 2 shows another embodiment of the present invention. FIG. 2 (a) shows a large number of porous plate portions 21 formed in the embodiment shown in FIGS. 1 (a) and (b). Instead of the hole 22, a nozzle-type blowing port 26 that protrudes inward is used. 2 (b), a lid 27 is integrally attached to the tip end side of the inlet 26 as shown in FIG. 2 (a), and the combustion exhaust gas 11a is refracted by the lid 27 after being blown from the inlet 26 and dried. It is designed to be blown into zone I.

  In the case of the embodiment as shown in FIG. 2 (a), when the external heat kiln furnace 1 is rotated, the waste 6 can be agitated by the respective blowing ports 26 protruding to the inside of the perforated plate portion 21, It is possible to enhance the direct contact effect with the combustion exhaust gas 11a.

  In addition, in the case of the embodiment as shown in FIG. 2B, in addition to the above-described effects, it is possible to prevent the possibility that the air inlets 26 are blocked by the waste 6 in advance.

  FIG. 3 shows another embodiment of the present invention. In the same configuration as shown in FIGS. 1 (a) and (b) and FIGS. 2 (a) and (b), the inlet 2 side end of the pyrolysis zone II is shown. Or a weir 28 of a required height is attached to the inner surface of the inner cylinder 1a in the vicinity of the outlet 3 side end of the drying zone I. When the waste 6 in the drying zone I moves to the pyrolysis zone II, the weir 28 And the residence time of the waste 6 in the drying zone I is adjusted by the height of the weir 28.

  Other configurations are the same as those shown in FIGS. 1A and 1B, and the same components are denoted by the same reference numerals.

  According to this embodiment, the waste 6 can be retained in the drying zone I, and the residence time of the waste can be adjusted by using the weirs 28 having different heights. It becomes possible to adjust the evaporation of moisture from the waste 6. In addition, it is necessary to take out the combustion exhaust gas 11a which has become about 350 ° C. as a heat source for indirect heating pyrolysis in the thermal decomposition zone II from the gas extraction line 17a at 150 ° C. or higher where low temperature corrosion does not occur. By appropriately adjusting the waste residence time in the drying zone I by the weir 28, the dry exhaust gas 11b containing a large amount of moisture can be taken out at 150 ° C. or higher.

  Further, FIGS. 4 (a), (b), and (c) show still another embodiment of the present invention. In the embodiment shown in FIGS. 1 to the porous plate portion 21 in the configuration in which the combustion exhaust gas 11a is blown from the porous holes 22 of the porous plate portion 21 to directly contact the waste 6. Instead, a diffuser tube 29 having a large number of blowing holes 30 is arranged in a circumferential direction and combined in a cylindrical shape, and a header 31 is attached to the heating flow path 10 outside the pyrolysis zone II, and one end of the header 31 is attached. The other ends of the many connected diffuser tubes 29 are attached to a ring plate 32 provided at the inlet 2 side end of the drying zone I. Further, the diffuser tubes 29 adjacent to each other in the circumferential direction are connected to each other by a connecting plate 33 to form a cylindrical shape, and the inside of the cylindrical shape is used as a drying zone so that gas is blown from each diffuser tube 29 to the drying zone I. It is. Other configurations are the same as those shown in FIG. 1A, and the same components are denoted by the same reference numerals.

  According to this embodiment, the combustion exhaust gas 11a after being used as a heat source for indirect heating pyrolysis in the pyrolysis zone II is distributed and distributed from the header 31 into each air diffuser 29, and is distributed to each air diffuser 29. The air is blown from the blow holes 30 that are opened. As a result, in the drying zone I, the waste 6 can be dried by the direct contact method in the same manner as in the above-described embodiments. Moreover, you may make it add the structure which provides the weir 28 as shown in FIG. 3 to this embodiment.

  In addition, this invention is not limited only to above-described embodiment, For example, as shown to FIG. 1 (A) etc., the drying zone formed in the front | former stage part by the side of the inlet 2 of the external heat kiln furnace 1 is shown. I allows the waste 6 to be dried so that the combustion exhaust gas 11a of about 350 ° C. after being used as a heat source for indirect heating pyrolysis in the thermal decomposition zone II can be discharged to the gas extraction box 17 at 150 ° C. or higher. The size of the drying zone I is not limited to the one shown in the figure, and the external heat kiln furnace 1 shown in the figure is outlined for easy understanding of the configuration. Of course, the present invention is not limited to the illustrated shape, and various modifications can be made without departing from the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS One Embodiment of the waste pyrolysis gasification method and apparatus of this invention is shown, (A) is a general | schematic cutting side view, (B) is an AA arrow expanded sectional view of (A). FIG. 2 shows another example of the perforated plate portion forming the drying zone shown in FIG. 1, (a) is an enlarged partial view when the hole is a nozzle-type blowing port, and (b) is a lid attached to the blowing port. FIG. It is a general | schematic cutting side view which shows the other form of implementation of this invention. The further another form of implementation of this invention is shown, (A) is a schematic cut | disconnection side view, (B) is an BB arrow expanded sectional view of (A). (C) is an enlarged cross-sectional view of a diffuser tube. It is a schematic diagram which shows an example of the conventional waste pyrolysis gasification apparatus. FIG. 2 is a schematic diagram showing an example of a waste pyrolysis gasification apparatus in which a conventional external heat kiln furnace is divided into a front stage part on the inlet side and a rear stage part on the outlet side and a pyrolysis gas containing a large amount of moisture is taken out from the front stage part. is there. It is the schematic which shows an example of the waste pyrolysis gasification apparatus of the structure which separately installed the dryer which dries waste by the direct contact system with combustion exhaust gas in the upstream of the conventional external heat kiln furnace.

Explanation of symbols

I Drying zone
II Pyrolysis Zone 1 External Heat Kiln Furnace 2 Inlet 3 Outlet 6 Waste 7A Pyrolysis Gas 10 Heating Channel 11 High Temperature Gas 11a Combustion Exhaust 11b Dry Exhaust 17a Gas Extraction Line 21 Perforated Plate 22 Holes 25 Lifter 28 Weir 29 Aeration Pipe

Claims (7)

  In the front stage which becomes the inlet side of the external heat kiln furnace in which one end side in the longitudinal direction is the inlet and the other end side is the outlet, and the waste supplied from the inlet side is thermally decomposed by indirect heating with high-temperature gas, Combustion exhaust gas after being used as a heat source for indirect thermal pyrolysis is directly blown into the furnace, and the waste is dried by direct contact between the exhaust flue gas to be injected and waste, and the combustion is rich in moisture. The exhaust gas is taken out from the inlet side, and then the dried waste is subjected to indirect heating and pyrolysis with high-temperature gas at the rear stage on the outlet side of the external heat kiln furnace, and the generated pyrolysis gas with less moisture is discharged to the outlet. A waste pyrolysis gasification method characterized by being taken out from the side.   Combustion exhaust gas after using high-temperature gas as a heat source for indirect heating and pyrolysis at the rear stage on the outlet side of the external heat kiln furnace is passed through the many holes in the front part on the inlet side of the external heat kiln furnace, and enters the furnace from the outer periphery. The waste pyrolysis gasification method according to claim 1, wherein the waste pyrolysis gasification method is performed.   An external heat kiln furnace in which one end side in the longitudinal direction is an inlet and the other end side is an outlet, and waste supplied from the inlet side is thermally decomposed by indirect heating with a high-temperature gas is connected to a front stage portion and an outlet on the inlet side. The rear stage part on the inlet side is a drying zone for drying waste by direct contact so that gas can be blown from the outer periphery into the furnace, and the rear stage part on the outlet side is , A pyrolysis zone that thermally decomposes waste by indirect heating with high-temperature gas, and waste that has been dried at the front stage is pyrolyzed at the rear stage so that a gas with a large amount of water is taken out from the inlet side, and the outlet side A waste pyrolysis gasifier having a structure in which pyrolysis gas with a small amount of water is taken out from the waste water.   4. The waste gas is directly contact-dried by directly injecting the flue gas having lowered temperature into the furnace in the drying zone after using the hot gas as a heat source for indirect heating pyrolysis in the pyrolysis zone. Waste pyrolysis gasifier.   The waste pyrolysis gasifier according to claim 3 or 4, wherein the gas is blown into the drying zone through a cylindrical perforated plate portion or a cylindrically arranged aeration tube.   The waste pyrolysis gasifier according to claim 3, 4 or 5, wherein lifters are provided at a predetermined interval in the circumferential direction inside the drying zone.   The waste pyrolysis gasification apparatus according to claim 3, 4, 5, or 6, wherein a weir for restricting the flow of waste is provided near a boundary between the drying zone and the pyrolysis zone.

Images