JP2005273975A - Waste treatment apparatus and waste treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a double damper for throwing wastes from being overheated, a positive pressure at the upper part of a primary combustion chamber from being formed, and a rather large amount of lump inflammable materials from being simultaneously dropped. <P>SOLUTION: This waste treatment apparatus comprises the primary combustion chamber 10 and a secondary combustion chamber 20. The primary combustion chamber forms a vertical in-furnace area allowing wastes W<SB>0</SB>thrown from the upper side to be stacked. A burner device 17 and an air injection device 55 are disposed on the lowermost part of the primary combustion chamber. A plurality of air injection holes 56 are disposed in the wall surface of a furnace, and a vertical flow passage 19 is formed in a waste bridge W<SB>10</SB>. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a waste treatment apparatus and a waste treatment method, and more specifically, an ultra-high temperature field suitable for complete sterilization of infectious waste is formed in a furnace using heat generated from waste. The present invention relates to a waste treatment apparatus and a waste treatment method.

  Waste from medical facilities, various research facilities, food factories, large lodging facilities, large dining facilities (hereinafter referred to as “medical facilities, etc.”) are biological materials, biological discharges, synthetic resins, fibrous materials, inorganic materials It contains various types of wastes such as system materials, metal materials, and animal and plant organs, which are difficult to separate for reasons of hygiene. In particular, the waste of medical facilities or medical-related organizations includes infectious waste that can be a source of infection, unlike normal facility waste, and even non-infectious waste that has no risk of infection is injected. Since it contains a wide variety of waste materials or waste materials such as needles, surgical instruments, bottles, organs, biological tissues, etc., it is virtually impossible to perform manual separation processing. For this reason, it is required to dispose of medical wastes economically and efficiently, without adversely affecting the environment, and for the staff engaged, safely and labor-saving, ideally It is desirable to treat all waste produced from medical facilities etc. within the generation area (in-hospital).

  In addition, in the case of incinerating waste that cannot be separated such that various kinds of waste materials are mixed, not only the waste is completely sterilized, but also various substances that are undesirable from the viewpoint of preventing air pollution, such as dioxin, etc. It is also important to adopt a treatment method that prevents the generation of pollutants as much as possible and does not adversely affect the surrounding environment.

  From this point of view, in recent years, an ultra-high temperature field has been formed in the furnace of an incineration facility by a plasma melting method that uses plasma radiant heat to form an ultra-high temperature field, or by the combustion heat of an oxygen burner. A waste treatment method that sterilizes and melts and discharges slag after volume reduction and solidification has been developed (for example, “melting technology of incineration ash” (by Ishikawajima-Harima Heavy Industries, Ltd., Masayuki Mizuno)). In addition, a system for reforming gasified gas or pyrolysis gas generated in such a gasification and melting process and using it as a fuel for power generation equipment has also been developed (Japanese Patent Laid-Open No. 2001-158885).

  The present inventor has a three-stage combustion chamber, that is, a primary combustion chamber for fragmenting waste, and a secondary for gasifying the fragmented waste as a treatment apparatus for waste that is difficult to separate such as medical waste. A waste treatment apparatus having a combustion chamber and a tertiary combustion chamber for completely burning gasified gas has been proposed (Japanese Patent Application No. 2003-36877).

According to the waste treatment apparatus having such a configuration, the portable container storing infectious waste is dismantled by the combustion reaction in the primary combustion chamber, and the container contents are partially burned. A small piece of content falls into the secondary combustion chamber. Therefore, while omitting preliminary steps such as separation, crushing, and sterilization / volume reduction, infectious waste stored in a portable container is treated at high temperature, and infectious waste is completely sterilized and incinerated. be able to. Moreover, according to this waste treatment apparatus, it is possible to apply a process including an exhaust gas high temperature treatment by the tertiary combustion chamber and a rapid cooling treatment of the high temperature exhaust gas by the cooling device, thereby effectively dioxin resynthesis. Can be prevented.
JP 2001-158885 Japanese Patent Application No. 2003-36877 Specification

However, the following problems were newly recognized in the practical application test of the waste treatment apparatus having the above-described configuration. That is,
(1) When a waste containing a relatively large amount of combustible material (waste plastic, etc.) with a high calorific value is introduced into the primary combustion chamber, the phenomenon that the combustion is transiently or temporarily activated in the upper part of the primary combustion chamber is observed. It is done. When a high-temperature combustion reaction occurs in the upper part of the primary combustion chamber, the waste dumping double damper device disposed at the top of the primary combustion chamber exceeds the heat resistance temperature of the metal constituting the damper, or the operating temperature of the damper device. There is a risk of exposure to high-temperature superheated atmosphere exceeding the limit.
(2) The waste treatment apparatus having the above configuration is intended for operation in which the negative pressure state of the primary combustion chamber is maintained by the exhaust gas induced pressure. On the other hand, the primary combustion chamber also functions as a quantitative buffer zone (buffer zone) that absorbs changes over time in the amount of waste input, so that a relatively large amount of waste is input to the primary combustion chamber, Highly stacked in the combustion chamber. However, when a relatively large amount of waste accumulates in the primary combustion chamber, the vertical gas flow path in the primary combustion chamber is blocked, and the exhaust gas attraction pressure that should act on the primary combustion chamber via the secondary combustion chamber is accumulated. Is blocked by waste. If the combustion reaction in the primary combustion chamber proceeds in this state, the internal pressure in the upper part of the primary combustion chamber is changed to a positive pressure (positive pressure). As a result, there is a concern that the combustion gas in the furnace leaks from the waste inlet to the outside. .
(3) In the practical application test of the above-mentioned waste treatment device, a relatively large amount of massive combustible material simultaneously falls from the primary combustion chamber to the secondary combustion chamber, thereby causing a rapid combustion reaction and a rapid combustion amount. A phenomenon in which an increase or explosive combustion reaction occurs instantaneously in the secondary combustion chamber was observed. When such a phenomenon occurs, the amount of air supplied to the secondary combustion chamber becomes transiently insufficient, and unburned components such as carbon monoxide tend to be excessively generated in the secondary combustion chamber.

The present invention has been made in view of such problems, and the object of the present invention is to provide a primary combustion chamber into which waste that is difficult to separate, such as infectious waste or medical waste, can be input, and primary combustion. In a waste treatment apparatus equipped with a secondary combustion chamber that primarily burns in the chamber and gasifies the waste that has fallen from the primary combustion chamber, (1) prevents overheating of the double dumper device for charging waste, (2) The positive pressure formation at the upper part of the primary combustion chamber is reliably prevented, and (3) The amount of air supplied to the secondary combustion chamber is reduced by gravity falling from the primary combustion chamber to the secondary combustion chamber. It is an object of the present invention to provide a waste treatment apparatus capable of avoiding a state where there is a transient shortage.

In order to achieve the above object, the present invention provides a primary combustion chamber in which waste that is difficult to separate can be charged, and a secondary combustion chamber that gasifies waste that has undergone primary combustion in the primary combustion chamber and has fallen due to gravity from the primary combustion chamber. In a waste treatment apparatus equipped with
The primary combustion chamber forms a vertical furnace region in which the waste charged from the upper portion can be accumulated, and a lowermost portion of the primary combustion chamber provided with a drop port communicating with the secondary combustion chamber Are provided with a burner device and an air injection device, and the burner device and the air injection device are configured to reduce the bottom part of the waste accumulated in the furnace area by the fuel and air injected to the lower part of the furnace area. Provided is a waste treatment apparatus characterized by burning.

  According to the above configuration of the present invention, the waste accumulated in the vertical furnace region is actively burnt by the supply of sufficient combustion air at the bottom of the primary combustion chamber, while the upper portion of the accumulated waste Then, the combustion reaction occurs relatively slowly due to the reduction in the amount of combustion air. Since the waste is introduced into the furnace from the upper part of the primary combustion chamber, the waste in the furnace is deposited in layers in the furnace by the fuel injection and air jet at the bottom and crosses the furnace wall. Are formed in the furnace region. Waste is replenished from above onto the uppermost bridge in the combustion atmosphere, but only limited air is supplied to the upper region of the uppermost bridge. For this reason, even if waste containing a relatively large amount of combustible substances (waste plastics, etc.) with a high calorific value that undergoes a rapid combustion reaction is thrown into the primary combustion chamber, It burns only slowly in the presence of and the upper part of the primary combustion chamber remains relatively cool. Therefore, according to the waste treatment apparatus configured as described above, a high-temperature superheated atmosphere exceeding the metal heat resistance temperature of the double dumper apparatus for waste input or exceeding the operating temperature limit of the double damper apparatus is present in the upper part of the primary combustion chamber. It can be prevented from forming and overheating of the double damper device can be prevented.

The present invention also includes a primary combustion chamber capable of inputting waste that is difficult to separate, and a secondary combustion chamber that gasifies waste that has undergone primary combustion in the primary combustion chamber and gravity dropped from the primary combustion chamber. In the processing device,
The primary combustion chamber forms a vertical furnace area in which the waste charged from the upper part can be accumulated,
A plurality of air injection holes opened toward the waste accumulated in the furnace region are arranged in the vertical direction on the wall surface of the furnace, and the upper region of the waste deposited in the furnace region and the secondary combustion chamber Provided is a waste treatment apparatus in which a longitudinal flow path communicating with each other is formed in waste by an air jet flow of the air injection port.

  According to such a configuration of the present invention, the combustion reaction of the waste accumulated in the furnace is locally activated by the air jets of the air injection ports, and the passage extends in the vertical direction corresponding to the arrangement of the air injection ports. Are locally formed in the waste deposited in the furnace. This vertical passage functions as a flow path that interconnects the upper region of the accumulated waste and the secondary combustion chamber, so that negative pressure (negative pressure) acting on the secondary combustion chamber is Acting on the upper part of the primary combustion chamber. Therefore, as long as the exhaust air induced pressure of the exhaust fan acts on the secondary combustion chamber, the upper portion of the primary combustion chamber always maintains a negative pressure state. Thus, according to the present invention, it is possible to avoid the formation of a positive pressure in the upper part of the primary combustion chamber, and to prevent a situation in which a sterilization-incomplete atmosphere or the like leaks from the double damper device to the outside.

  In addition, most of the waste accumulated in the furnace is subjected to dry distillation in the presence of air supplied to the furnace by the air injection device and / or the air injection port. The gas body generated by the dry distillation combustion flows into the secondary combustion chamber from the dropping port. Unburned solids that fall from the accumulated waste into the secondary combustion chamber are mainly composed of porous carbon after dry distillation, so explosive combustion of unburned solids that have fallen into the secondary combustion chamber occurs. hard. Therefore, the supply of air to the secondary combustion chamber is temporarily insufficient due to explosive combustion of unburned solids, which prevents the generation of relatively large amounts of unburned carbon and tar that are difficult to reburn. In addition, it is possible to avoid the phenomenon that dioxins are generated with the production of unburned carbon and tar.

From another point of view, the present invention provides a vertical primary combustion chamber in which waste that is difficult to separate can be input, and secondary combustion that gasifies waste that has undergone primary combustion in the primary combustion chamber and gravity dropped from the primary combustion chamber. In a method for disposing of infectious waste using a waste treatment apparatus equipped with a chamber,
The amount of waste accumulated in the primary combustion chamber is regulated within a range of 0.5 to 2 times the waste treatment amount / time during steady operation of the primary combustion chamber. Waste is thrown into the primary combustion chamber from above,
The lowermost part of the waste is burnt by the fuel supply and the air jet of the burner device and the air injection device arranged at the lowermost part of the primary combustion chamber, and the dry jet combustion of the waste accumulated in the primary combustion chamber is carried out by the air jet The present invention provides a method for disposing of infectious waste, which is characterized by being advanced by air.

From still another aspect, the present invention provides a vertical primary combustion chamber capable of throwing in difficult-to-separate waste, and a secondary that gasifies waste that has undergone primary combustion in the primary combustion chamber and has fallen by gravity from the primary combustion chamber. In a method for disposing of infectious waste using a waste treatment apparatus equipped with a combustion chamber,
The amount of waste accumulated in the primary combustion chamber is regulated within a range of 0.5 to 2 times the waste treatment amount / time during steady operation of the primary combustion chamber. Waste is thrown into the primary combustion chamber from above,
An air flow is jetted from the wall surface of the furnace on the side surface of the waste accumulated in the furnace area, and a combustion reaction between the air flow and the waste is locally advanced, and the upper region of the waste and the secondary Provided is a method for disposing of infectious waste, characterized in that a vertical flow path for communicating with a combustion chamber is formed in the waste.

  According to the above configuration of the present invention, the amount of accumulated waste (weight) is limited to a range of 0.5 to 2 times the amount of waste treated (weight) / time in the primary combustion chamber. . For example, the amount of waste accumulated in the primary combustion chamber is limited to a range corresponding to 30 minutes equivalent (0.5Q) to 120 minutes equivalent (2Q) with respect to the waste treatment amount Q per hour in the primary combustion chamber. Is done. Here, the weight and physical properties of the waste container and its contents put into the primary combustion chamber change on a daily basis according to the operation status of the facility, but the formation of the waste bridge in the primary combustion chamber is For waste that changes quantitatively and qualitatively, not only is it advantageous for stable operation of the waste treatment equipment, but it also functions effectively to ensure a high-temperature history of the waste. To do. The function of ensuring a high temperature history is particularly important in a waste treatment apparatus for infectious waste. That is, in the waste treatment apparatus of the present invention, the amount of waste accumulated in the primary combustion chamber is regulated as described above by adjusting the amount of waste input, so that the weight and physical properties of the contents of the waste container are not affected. A desired waste bridge is always formed in the primary combustion chamber, thereby ensuring a sufficient high temperature history of the waste and stably operating the waste treatment apparatus.

  In addition, by burning the bottom surface of the waste bridge with the burner device and the air injection device at the lowermost part of the primary combustion chamber, and promoting the dry distillation combustion of the waste accumulated in the primary combustion chamber, It is possible to prevent a gravity drop from the primary combustion chamber to the secondary combustion chamber.

  Furthermore, the formation of the vertical flow path ensures that the exhaust gas attraction pressure always acts on the upper area of the waste through the secondary combustion chamber and the vertical flow path, so that positive pressure formation at the upper part of the primary combustion chamber is ensured. Can be prevented.

  Preferably, dry distillation combustion of the waste accumulated in the primary combustion chamber proceeds by the air supplied into the furnace.

According to the above configuration of the present invention in which the burner device and the air injection device are arranged at the lowermost part of the primary combustion chamber, the double damper device for throwing in waste is prevented from being overheated and a relatively large amount of massive combustible material is primary. A state in which the amount of air supplied to the secondary combustion chamber is transiently insufficient can be avoided by gravity falling from the combustion chamber to the secondary combustion chamber.

  In addition, according to the above-described configuration of the present invention in which a plurality of air injection ports are arranged in the vertical direction on the inner wall surface of the furnace, positive pressure formation at the upper part of the primary combustion chamber is surely prevented, and a relatively large amount of massive combustibles are primary. A state in which the amount of air supplied to the secondary combustion chamber is transiently insufficient can be avoided by gravity falling from the combustion chamber to the secondary combustion chamber.

  Preferably, the waste treatment apparatus includes three-stage combustion chambers, that is, the primary and secondary combustion chambers, and a tertiary combustion chamber that completely burns the gasified gas in the secondary combustion chamber. More preferably, the unburned solid that has fallen into the secondary combustion chamber is retained in the secondary combustion chamber by a high-speed jet of a high-temperature oxidant, and is stirred and gasified. The gasified gas is completely combusted in the tertiary combustion chamber and exhausted. Of the solids that cannot be incinerated or pyrolyzed, the solids that can be melted remain as molten slag at the bottom of the secondary combustion chamber, and the solids that cannot be melted are embedded in the molten slag. The molten slag at the bottom of the secondary combustion chamber reacts with the high temperature oxidant supplied to the secondary combustion chamber and generates heat, contributing to the maintenance of the high temperature atmosphere in the secondary combustion chamber. The molten slag is cooled and solidified after the waste treatment apparatus is stopped and discharged outside the apparatus, or continuously or intermittently during operation of the waste treatment apparatus.

  Preferably, the tertiary combustion chamber has a combustion air injection device for injecting combustion air into the tertiary combustion chamber, and the combustible portion of the gasification gas flowing into the tertiary combustion chamber is the combustion of the combustion air injection device. It reacts with the working air and burns completely, raising the temperature of the exhaust gas in the tertiary combustion chamber to a high temperature of 1000 ° C. or higher, and the high temperature exhaust gas in the tertiary combustion chamber is supplied to the cooling device. The cooling device rapidly cools the exhaust gas to a temperature of 200 ° C. or less. The process including the high-temperature exhaust gas treatment by the tertiary combustion chamber and the high-temperature exhaust gas quenching treatment by the cooling device effectively prevents dioxin resynthesis and suppresses the generation of dioxins.

  In a preferred embodiment of the present invention, the primary combustion furnace forming the primary combustion chamber is oriented substantially vertically, and the cross section of the primary combustion chamber shrinks stepwise downward, so that the The lower end forms a drop port that communicates with the secondary combustion chamber. More preferably, the lowermost end portion of the primary combustion chamber is reduced in diameter to a conical shape to prevent free fall of the waste charged into the primary combustion chamber. The air injection device and the burner device are arranged in such a conical reduced diameter portion, and inject the air jet and the fuel toward the center of the reduced diameter portion. Preferably, the air injection device includes a plurality of air injection nozzles arranged in the conical diameter reduced portion with a predetermined angular interval (for example, an angular interval of 120 °) in the circumferential direction.

  According to a further preferred embodiment of the present invention, the plurality of air injection ports are arranged on the furnace wall surface at equal intervals in the furnace axis direction. Preferably, the planar position of the air injection port is set at a position facing the burner device, and the level (height) of the air injection port is set above the conical diameter reduced portion.

  If desired, the preheated air is supplied to the air injection device and / or the air injection port. If desired, air or gas with an appropriately adjusted oxygen concentration, air containing water vapor or the like may be supplied to the air injection device and / or the air injection port.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a system flow diagram showing an overall configuration of an infectious waste disposal apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the waste treatment apparatus includes a double damper device, a primary combustion chamber, a secondary combustion chamber, a tertiary combustion chamber, a cooling device, a dust collecting device, and a high-temperature air generating device. Generally, infectious waste is transferred to a waste disposal apparatus in a state of being stored in a transport container. A transport container containing a wide variety of infectious waste is put into the primary combustion chamber via a double damper device. The transfer container is burned or melted in the primary combustion chamber and disassembled. The waste in the container is ignited by the combustion operation of the primary burner device, gasified by the air jets of the air injection device and the air injection port, and the gasified gas flows into the secondary combustion chamber. The primary combustion chamber is a maintenance burner device (shown by a broken line) that raises the furnace temperature of the primary combustion chamber to a temperature of 1000 ° C. or higher in order to incinerate dioxins adhering to the refractory constituting the furnace body. Prepare. The maintenance burner device is activated when no waste is loaded.

  The infectious waste transport container is sequentially introduced into the primary combustion chamber from the upper part of the primary combustion chamber via the double damper device, and the transport container is burned or melted as described above to disassemble and infect the container. Waste is released into the furnace, spread apart or dispersed, and accumulates in the vertical furnace area of the primary combustion chamber. The accumulated waste is actively burned and burnt at the lowermost part of the primary combustion chamber by the primary burner device arranged at the lowermost part and the fuel injection and air jet of the air injection port. On the other hand, a relatively slow combustion reaction proceeds on top of the accumulated waste. Waste in the furnace accumulates in layers in the furnace area, forming a waste bridge that bridges the furnace wall. The infectious waste transport container is sequentially replenished from the top onto the uppermost bridge where oxidation heat is generated.

  The high-temperature air generator heats air at normal temperature (temperature equivalent to atmospheric temperature) to a high temperature of 500 ° C. or higher, preferably 800 ° C., and supplies high-temperature air to the high-temperature air injection device disposed in the main chamber of the secondary combustion chamber. Supply. The secondary combustion chamber includes a sub chamber that follows the main chamber. The high-temperature air jet injected by the high-temperature air injection device prevents the combustion gas, pyrolysis gas, solid or liquid suspended solids, etc. flowing into the main chamber from the primary combustion chamber from being blown into the sub chamber. The material is recirculated into the main chamber along with the container and a small piece of the container contents and stirred in the main chamber. The container and the small pieces of the container contents are oxidized in the main chamber and reduced and burned to generate heat.

  The flow rate of the high-temperature air jet flow is preferably set to 30 m / s or more, and more preferably 50 to 150 m / s. The high-temperature air stream ejected at a high speed is ejected into the main chamber of the secondary combustion chamber, and at the same time, mixed with the combustion gas and the pyrolysis gas in the main chamber to quickly reduce the oxygen concentration to 10% or less and 1000 to 1200. The temperature rises to a temperature higher than or equal to 0 ° C., contacts and mixes with the solid or liquid combustible substance floating in the main chamber, and is reduced and burned. For this reason, an extremely high-temperature spot is not generated in the main chamber, and a uniform flame is formed at a temperature of about 1500 ° C.

  Due to the mixing contact with the high-temperature air jet, the thermally decomposable pieces are thermally decomposed and gasified, and the meltable pieces remain at the bottom of the main chamber as molten slag. The molten slag solidifies after the waste treatment apparatus is stopped and cooled, and is discharged from the main room, or is discharged continuously or intermittently from the outlet of the main room during the operation of the apparatus.

  The gasified gas generated in the main chamber flows into the tertiary combustion chamber via the sub chamber and mixes with the combustion air supplied to the tertiary combustion chamber. Combustible components such as carbon monoxide, methane, and hydrogen contained in the gasification gas react with the combustion air supplied from the combustion air supply port to the tertiary combustion chamber and are completely combusted in the tertiary combustion chamber. The flue gas flowing out from the tertiary combustion chamber to the cooling device has a temperature of about 1000 to 1200 ° C.

  The combustion gas in the tertiary combustion chamber is introduced into a cooling device and rapidly cooled to about 200 ° C. in a time of several seconds. A cooling tower equipped with a cooling water spray facility can be suitably used as the cooling device. The cooled combustion gas is purified by a dust collector such as a bag filter and exhausted outside the system via an exhaust fan and a stack (not shown). The exhaust fan's exhaust attraction pressure acts on the secondary combustion chamber, the tertiary combustion chamber, the purification device, and the dust collector, and the exhaust attraction pressure acts on the entire flow path of the gasification gas generated in the secondary combustion chamber. Therefore, a gas flow from the main chamber toward the exhaust fan is formed throughout the system, and the gas flow path maintains a negative pressure (negative pressure) as a whole. In addition, as the high-temperature air generator, an air supply heating device disclosed in Japanese Patent Application No. 10-189 (Japanese Patent Laid-Open No. 10-246428) by the applicant of the present application can be suitably used. Further, an auxiliary burner device that can supply auxiliary fuel for compensating for the shortage of heat generated by waste to the secondary combustion chamber may be disposed in the secondary combustion chamber.

  The furnace temperature detection means T constituting the control system of the waste treatment apparatus is disposed in each combustion chamber, and the primary burner device and the auxiliary burner device detect the furnace temperature of each combustion chamber under the control of the control unit C / U. Operates in relation to values etc. The control unit C / U operates each burner device so as to maintain the furnace temperature of each combustion chamber at a predetermined temperature (for example, 1000 ° C.) or more at the time of starting or when the waste heat generation is insufficient. The control unit C / U also controls the drive unit D of the high-temperature air generator to variably control the high-temperature air supply amount, the air temperature, and the like.

  FIG. 2 is a longitudinal sectional view showing an embodiment of the waste treatment apparatus, and FIGS. 3A and 3B are sectional views taken along lines AA and BB in FIG.

  As shown in FIG. 2, the waste treatment apparatus includes a primary combustion furnace 1, a secondary combustion furnace 2, and a tertiary combustion furnace 3, and the primary combustion chamber 10, the secondary combustion chamber 20, and the tertiary combustion chamber 30 are provided for each furnace 1. Formed in a few furnaces. The furnace body 11 of the primary combustion furnace 1 has its furnace axis oriented vertically, and the furnace axis of the furnace body 11 is orthogonal to the furnace axis of the secondary combustion furnace 2. The secondary combustion chamber 20 of the secondary combustion furnace 2 includes a vertical vertical main chamber 21 and a horizontal horizontal sub-chamber 22, and the entire furnace body 23 has a horizontal furnace shaft. The furnace body 31 of the tertiary combustion furnace 30 has its furnace axis oriented vertically. The bottom of the tertiary combustion chamber 30 communicates with the sub chamber 22 via the communication passage 33, and the top of the tertiary combustion chamber 30 is connected to the exhaust gas duct 39.

The primary combustion furnace 1 includes a double damper device 12 and a primary burner device 17 (17a, 17b). The double damper device 12 includes a pair of movable dampers 13 and 14 that are prohibited from being simultaneously opened, and an intermediate chamber 15 between the dampers 13 and 14. The double damper device 12 opens and closes the movable dampers 13 and 14 in a sliding manner by a driving device such as a fluid pressure operated cylinder device. The waste container W ₀ containing infectious waste is introduced into the intermediate chamber 15 from a supply device (not shown) such as a lifter in connection with the opening / closing control of the dampers 13 and 14, and passes through the intermediate chamber 15. Charged into the primary combustion chamber 10. The burner device 17 is combusted by supplying fuel such as LPG and combustion air, heats the waste container W ₀ in the primary combustion chamber 10, incinerates or dismantles / divides the container, and the contents of the container Encourage smaller pieces. A small piece drop port 18 is formed in the lower part of the primary combustion chamber 10, and a small piece W ₁ of the container and the container contents falls into the main chamber 21 of the secondary combustion chamber 20 from the drop port 18. By appropriately designing the shape and opening area of the drop opening 18, a small piece W ₁ having an appropriate size is gravity dropped from the primary combustion chamber 10 to the main chamber 21.

  A maintenance burner device 70 (shown by a broken line) is disposed on the top wall of the primary combustion chamber 10. This burner device 70 is operated only during maintenance to incinerate dioxins adhering to the refractory constituting the furnace body. The furnace temperature of the primary combustion furnace 1 rose to a high temperature of 1000 ° C. or more in an empty state by operating the burner device 70 when waste was not charged (during maintenance), and adhered to the wall surface in the furnace. Dioxins are incinerated. The combustion exhaust gas in the primary combustion chamber 10 is exhausted outside the system through the secondary combustion chamber 20 and the tertiary combustion chamber 30.

  The main chamber 21 of the secondary combustion furnace 2 has an elliptical cross section whose major axis is directed in the furnace axis direction of the secondary combustion furnace 2 as shown in FIG. The opening 25 of the sub chamber 22 is arranged at the upper part and the long axis end of the main chamber 21 and faces the main chamber 21. The hot metal pot 24 is detachably connected to the furnace body 23 by a connecting means 27 that can be separated and connected. The connecting means 27 has, for example, a flange structure that can be fastened and disassembled with bolts and nuts. The in-pot region constitutes a main chamber lower portion continuous with the main chamber upper portion in the furnace body 23. In the main chamber 21, an auxiliary burner device 7 (indicated by a virtual line) capable of supplying auxiliary fuel into the main chamber 21 is disposed at a predetermined position. The control unit C / U (FIG. 1) operates the auxiliary burner device 7 in association with the furnace temperature of the main chamber 21 detected by the furnace temperature detection means T (FIG. 1). For example, when the calorific value of the waste is insufficient, the auxiliary burner device 7 injects fuel into the main chamber 21 to compensate for the deficiency of the calorific value in the main chamber 21.

  The injection port 40 of the high-temperature air injection device 4 opens in the top wall of the main chamber 21 in the vicinity of the opening 25. The injection device 4 injects a high-speed jet of high-temperature air downward so that airflow and floating substances that are about to flow out from the main chamber 21 to the sub-chamber 22 are directed to the lower portion of the main chamber. Preferably, the tip of the injection port 40 is designed to have an appropriate opening area and size so as to speed up the high-temperature air injection flow to 50 to 150 m / s, and has an orifice or a reduced diameter portion as desired.

The hot air has a temperature of 500 ° C. or higher, preferably 800 ° C. or higher, more preferably 1000 ° C. or higher. Piece W ₁ dropped from the drop port 18 in the main chamber 21, and oxidized in contact with the high velocity jet of hot air, thermal decomposition and for volume reduction. Residue of small pieces W ₁ is deposited on the bottom of the main chamber 21 as a molten slag S. Solid particles, mist-like substances, soot particles, heavy metals and pyrolysis gas that have flowed into the main chamber 21 through the drop port 18, and pyrolysis gas and combustion gas generated in the main chamber 21 cross the opening 25. Alternatively, it is attracted to a high-speed jet of high-temperature air that traverses, forcibly circulates in the main chamber 21, and is stirred by the kinetic energy of the high-speed jet. The high-speed jet is in contact with the molten slag S at the bottom of the main chamber and promotes combustion of unburned content in the slag S.

Due to the heat generation of the small piece W ₁ , the molten slag S, the solid particles, the mist-like substance and the pyrolysis gas, the temperature in the main chamber 21 reaches about 1500 ° C., and the volume reduction and melting of the small piece W ₁ are promoted. The molten slag S is cooled and solidified by the suspension of the waste treatment apparatus. The pot 24 is removed by releasing the connecting means 27, and the solidified material in the pot 24 is taken out from the pot 24 and discarded. In addition, an unmelted metal piece etc. are discarded in the state embedded in the slag solidified material.

  The gasified gas in the main chamber 21 flows into the sub chamber 22 from the opening 25 under the exhaust attraction pressure of the exhaust fan (FIG. 1), and flows into the tertiary combustion chamber 30 from the sub chamber 22 through the communication path 33. . In the sub chamber 22, an auxiliary burner device 6 (shown by phantom lines) capable of supplying auxiliary fuel into the sub chamber 22 is disposed at a predetermined position, for example, at the end of the sub chamber 22. The control unit C / U (FIG. 1) is connected to temperature detection means (FIG. 1) for detecting the gas temperature in the tertiary combustion chamber 30, and the auxiliary burner device 6 in the sub chamber 22 controls the control unit C / U. It operates in relation to the gas temperature of the tertiary combustion chamber 30 below. Since the auxiliary burner device 6 injects fuel into the sub chamber 22 when the gas temperature in the tertiary combustion chamber 30 is lowered, the temperature of the gasification gas flowing into the tertiary combustion chamber 30 is stabilized.

  The tertiary combustion furnace 3 includes combustion air injection devices 35 and 36 that are arranged vertically at a predetermined interval. The gas flowing into the tertiary combustion chamber 30 from the sub chamber 22 contains a relatively large amount of carbon monoxide and the like, and the combustible component in the gas reacts with the combustion air injected from the injection devices 35 and 36, Burn completely. The temperature in the furnace of the tertiary combustion chamber 30 partially reaches a temperature of 1500 ° C. or higher, and the exhaust gas at the top outlet 32 maintains a gas temperature of 1000 to 1200 ° C.

  The exhaust gas in the tertiary combustion chamber 30 is supplied to the cooling device (FIG. 1) through the exhaust gas duct 39, and after being rapidly cooled to about 200 ° C. within a time of several seconds in the cooling device, a dust collector such as a bag filter ( The dust is removed by FIG. 1) and discharged to the atmosphere through an exhaust fan (FIG. 1) and a stack (not shown). The process in which the exhaust gas is heated to a high temperature by the tertiary combustion chamber 30 and the high temperature gas is rapidly cooled by the cooling device prevents the recombination of dioxins, so that the generation of dioxins in the waste treatment device is suppressed.

  4 is an enlarged longitudinal sectional view showing the structure of the primary combustion furnace 1, and FIGS. 5A to 5C are sectional views taken along lines CC, DD and EE in FIG. It is. FIG. 6 is a schematic longitudinal sectional view showing an outline of a waste bridge formed in the primary combustion chamber 10.

  The primary combustion chamber 10 in the primary combustion furnace 1 has a circular cross section around the furnace shaft 50 of the furnace body 11 over the entire height, and the uppermost diameter is set to the maximum diameter D. The furnace inner wall surface 51 of the furnace body 11 includes conical diameter-reduced portions 52 and 53 that gradually reduce the in-furnace region, and the lower end opening of the lower diameter-reduced portion 53 forms the small piece drop port 18. The distance H between the upper end of the drop port 18 and the furnace top wall is appropriately set according to the processing amount of the waste treatment apparatus.

  The primary burner device 17 includes first and second burner units 17a and 17b. The first burner unit 17a is disposed slightly above the reduced diameter portion 53, and is inclined downward at a predetermined angle with respect to the furnace shaft 50. The second burner unit 17b is disposed at the reduced diameter portion 53, and Oriented in a direction perpendicular to the axis 50 (horizontal direction). Each burner unit 17a, 17b is arranged at a position aligned vertically, and is arranged so as to inject fuel and combustion air toward the central region of the reduced diameter portion 53.

  The primary combustion furnace 1 also includes a first air injection device 55. As shown in FIG. 5C, the first air injection device 55 includes a plurality of air injection nozzles 55a, 55b, and 55c provided in the reduced diameter portion 53. Each nozzle is substantially the same as the burner unit 17b. At the same level, they are arranged at a predetermined angular interval (in this example, a central angle of 120 ° around the furnace axis). The air injection nozzle 55b is arranged at an angular position facing the burner unit 17b, and the air injection nozzles 55a and 55c are arranged symmetrically on both sides of the burner unit 17b. Each air injection nozzle 55a, 55b, 55c is oriented so as to inject an air jet horizontally toward the center of the reduced diameter portion 53.

  The primary combustion furnace 1 further includes a second air injection device 56 (air injection nozzles 56a, 56b, 56c, 56d) that forms an air injection port (FIG. 1). The air injection nozzles 56a to 56d are arranged in the furnace body 11 with a predetermined interval (equal interval in this example) between the reduced diameter portions 52 and 53 in the vertical direction. As shown in FIG. 5B, each of the air injection nozzles 56a to 56d is arranged at an angular position facing the burner unit 17a, and is aligned in the vertical direction.

  Air supply pipes 57 and 58 are connected to the air injection nozzles 55a to 55c and 56a to 56d, and a control valve 59 is interposed in each of the air supply pipes 57 and 58. The control valve 59 and the burner units 17a and 17b are connected to the control unit C / U (FIG. 1) via a control signal line, and the air injection amounts of the air injection nozzles 55a to 55c and 56a to 56d and the burner units 17a and 17b. Is controlled by the control unit C / U in association with the furnace temperature detected by the furnace temperature detection means T (FIG. 1).

The waste container W ₀ introduced into the uppermost portion of the primary combustion chamber 10 via the double damper device 12 is ignited by the combustion operation of the first and second burner units 17a and 17b, and is initially burned or melted. And then dismantle. The container contents are also initially burned or melted by the combustion heat of the burner units 17a, 17b, and the relatively large size contents decompose. The container W ₀ and its contents are dismantled due to the gradual reduction of the region in the furnace of the primary combustion chamber 10, the restriction of the opening area of the drop port 18, the action of the burner units 17 a and 17 b and the air injection nozzles 55 a to 55 c. Or, it is accumulated in the primary combustion chamber ₁₀ as decomposed waste W _{10, and} as shown in FIG. 6A, a waste bridge having a substantially three-layer structure composed of an upper layer W ₁₁ , an intermediate layer W ₁₂ , and a lower layer W _{13 is} formed in a furnace. Form in. The waste bridge crosses the inside of the furnace so as to bridge the furnace wall surface except for the longitudinal flow path 19 (FIG. 6B) formed locally.

Here, the waste to be introduced into the primary combustion chamber 10, the amount of such small pieces W ₁ dropping from the chute 18 into the main chamber 21 equilibrium during operation of the waste processing apparatus, for steady state. Therefore, the amount of waste that can be input during steady operation in which the amount of waste input and the amount of fall are balanced can be defined as the rated processing amount Q (waste processing amount per hour) of the primary combustion furnace 1. In order to ensure a high temperature history for complete sterilization of infectious waste, the amount of waste accumulated in the primary combustion chamber 10 is in the range of 0.2 to 2.5 times the rated treatment amount Q of the primary combustion chamber 10. (Range of 12 minute equivalent (0.2Q) to 150 minute equivalent (2.5Q)), preferably 0.5 times to 2.0 times the rated processing amount Q of the primary combustion chamber 10 (30 It is desirable to maintain or limit the minute equivalent (0.5Q) to 120 minutes equivalent (2Q). By introducing an appropriate amount of waste, a waste bridge effective in preventing overheating of the double damper device 12 is formed in the primary combustion chamber 10. The waste container W ₀ does not necessarily have to be input to the primary combustion furnace 1 at equal input intervals or regular time intervals, and may be input to the primary combustion furnace 1 intermittently or irregularly. Disposal in which the waste container W ₀ is not put into the primary combustion furnace 1 until the amount of waste accumulation is reduced to 0.5Q by the operation of the primary combustion furnace 1 after the accumulation of the waste quantity 2Q is formed in the primary combustion chamber 10. An article input method may be adopted.

Waste lower W _13, the first and second burner units 17a, is ignited by the combustion operation of 17b, and burning every combustion state, waste W ₁₀ deposited in the furnace, the air injection nozzles 55a to 55c, Dry distillation combustion is performed by combustion air injected from 56a to 56d. Gas bodies generated by dry distillation flow into the main chamber 21 from the drop port 18, and whisker-like solids peel off from the dome-shaped lower surface of the bridge-like lower layer W ₁₃ as small pieces W ₁ and enter the main chamber 21. Fall.

The burner units 17a and 17b are arranged at the lowermost part of the primary combustion chamber 10 so that the air injection nozzles 55a to 55c and 56a to 56d supply a relatively large amount of combustion air to the lower part of the primary combustion chamber 10. because are arranged, the upper layer W ₁₁ is relatively small amount of combustion air is merely supplied. For this reason, even when a waste material containing a relatively large amount of waste plastic or the like having a rapid combustion reaction is mixed into the primary combustion chamber 10, the waste W ₁₀ is separated into the upper layer W ₁₁ and the intermediate layer. W ₁₂ burns relatively slowly. Therefore, the temperature of the upper layer W ₁₁ and the intermediate layer W ₁₂ is relatively lower than the temperature of the lower layer W ₁₃ , and the primary combustion of the waste containing a relatively large amount of high calorific combustible material (waste plastic, etc.). even when placed in a room, furnace temperature rise in the region above the upper W ₁₁ is suppressed, it is possible to prevent overheating of the double damper device 12.

In addition, a locally active combustion reaction occurs in the vicinity of the air injection ports of the air injection nozzles 56a to 56d by the air jets of the air injection nozzles 56a to 56d arranged in a vertical line in the primary combustion chamber 10. In this zone, waste W ₁₀ is relatively early spalled as pieces W _1, since the fall in the main chamber 21, the longitudinal direction of the channel 19 is formed along the air injection nozzles 56a to 56d. Since the flow path 19 allows the upper area of the upper layer W ₁₁ and the main chamber 21 to communicate with each other, the exhaust attraction pressure of the exhaust fan (FIG. 1) acts on the upper area of the upper layer W ₁₁ via the flow path 19. Therefore, as long as the main chamber 21 maintains a negative pressure (negative pressure) state based on the atmospheric pressure, the upper region of the upper layer W ₁₁ maintains a negative pressure state. That is, the positive pressure (positive pressure) that releases the combustion gas in the primary combustion chamber 10 to the atmosphere from the clearance formed in the movable part of the double damper device 12 is the uppermost portion (upper layer W ₁₁ ) of the primary combustion chamber 10. It is not formed in the upper region).

Furthermore, most of the waste W ₁₀ deposited in the furnace, the air injection nozzles 55a to 55c, 56a to 56d are carbonization combustion by the air supplied to the furnace. The gas body generated by the dry distillation combustion flows into the main chamber 21 through the drop port 18. The unburned solids that drop from the accumulated waste W ₁₀ into the main chamber 21 by gravity are mainly composed of porous carbon after dry distillation, so explosive combustion of the unburned solids that have fallen into the secondary combustion chamber occurs. It is hard to do. Accordingly, the amount of air supplied to the main chamber 21 temporarily becomes short due to the explosive combustion of the unburned solids, and as a result, a relatively large amount of unburned carbon and tar that are difficult to reburn are generated in the main chamber 21. In addition, it is possible to avoid a situation in which dioxins are generated with the production of unburned carbon and tar.

  FIG. 7 is a schematic cross-sectional view showing a modified example regarding the arrangement of the air injection nozzles 56a to 56d and the burner units 17a and 17b.

  As shown in FIG. 7A, the air injection nozzles 56 a to 56 d are alternately arranged at an angle α (for example, an angle of 30 °), and the inner wall surface of the furnace has a zigzag arrangement as viewed from the center of the primary combustion chamber 10. 51 may be positioned.

  Further, as shown in FIG. 7B, the burner units 17a and 17b may be arranged on the furnace inner wall surface 51 with an angle β (for example, an angle of 30 °).

  Further, as shown in FIG. 7C, a pair of air injection nozzles 56a to 56d with an angle interval of an angle γ (for example, an angle of 60 °) can be disposed at each level of the furnace inner wall surface 51. is there.

  The preferred embodiments and examples of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments and examples, and is within the scope of the present invention described in the claims. Various modifications or changes are possible, and it goes without saying that these modifications or modifications are also included in the scope of the present invention.

  For example, in the above embodiment, the furnace shaft of the primary incinerator 1 is vertically oriented, but the furnace shaft can be slightly inclined.

  The number and arrangement of the burner units 17a and 17b and the air injection nozzles 55a to 55c and 56a to 56d can be appropriately changed in design according to the operating conditions, size, capacity, and the like of the furnace.

Furthermore, although the primary combustion furnace 1 has a structure including the double damper device 12, the present invention is similarly applied to a primary combustion furnace including a waste input unit having another structure. To get.
Alternatively, the maintenance burner device 70 may not be permanently installed in the primary combustion furnace 1, but the double damper device 12 may be temporarily removed during maintenance to attach the burner device 70 to the primary combustion furnace 1.

  The present invention includes a primary combustion chamber in which waste that is difficult to separate, such as infectious waste, can be input, a secondary combustion chamber that performs primary combustion in the primary combustion chamber and gasifies waste that has fallen by gravity from the primary combustion chamber, It is applied to a waste treatment apparatus equipped with

  In particular, the present invention is preferably applied to a waste treatment apparatus that completely sterilizes infectious waste containing materials that are difficult to crush and melt, such as metal pieces, in an ultra-high temperature field.

It is a system flowchart which shows the whole structure of the infectious waste processing apparatus which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows the Example of a waste disposal apparatus. It is sectional drawing in the AA line and BB line of FIG. It is an expanded longitudinal cross-sectional view which shows the structure of a primary combustion furnace. It is sectional drawing in CC line of FIG. 4, DD line, and EE line. It is a schematic longitudinal cross-sectional view which shows the outline | summary of the waste bridge formed in a primary combustion chamber. It is a schematic cross section which shows the modification regarding arrangement | positioning of an air injection nozzle and a burner unit.

Explanation of symbols

1: primary combustion furnace 2: secondary combustion furnace 3: tertiary combustion furnace 4: high-temperature air injection device 10: primary combustion chamber 12: double damper device 17: primary burner device 19: longitudinal flow path 20: secondary combustion chamber 21: Main chamber 22: Sub chamber 30: Tertiary combustion chamber 55: First air injection device (air injection device)
55a to 55c: Air injection nozzle 56: Second air injection device (air injection port)
56a to 56d: air injection nozzle W _0: waste container W _1: piece W _10: layered waste W _11: upper W _12: intermediate layer W _13: lower layer

Claims (13)

In a waste treatment apparatus comprising a primary combustion chamber capable of charging waste that is difficult to separate, and a secondary combustion chamber that gasifies waste that has undergone primary combustion in the primary combustion chamber and dropped from the primary combustion chamber,
The primary combustion chamber forms a vertical furnace region in which the waste charged from the upper portion can be accumulated, and a lowermost portion of the primary combustion chamber provided with a drop port communicating with the secondary combustion chamber Are provided with a burner device and an air injection device, and the burner device and the air injection device are configured to reduce the bottom part of the waste accumulated in the furnace area by the fuel and air injected to the lower part of the furnace area. A waste treatment apparatus characterized by burning. In a waste treatment apparatus comprising a primary combustion chamber capable of charging waste that is difficult to separate, and a secondary combustion chamber that gasifies waste that has undergone primary combustion in the primary combustion chamber and dropped from the primary combustion chamber,
The primary combustion chamber forms a vertical furnace area in which the waste charged from the upper part can be accumulated,
A plurality of air injection holes opened toward the waste accumulated in the furnace region are arranged in the vertical direction on the wall surface of the furnace, and the upper region of the waste deposited in the furnace region and the secondary combustion chamber A waste treatment apparatus characterized in that a longitudinal flow path communicating with each other is formed in waste by an air jet flow of the air injection port.   The waste treatment apparatus according to claim 1 or 2, further comprising a tertiary combustion chamber for completely burning the gasified gas generated in the secondary combustion chamber.   The furnace axis of the primary combustion furnace forming the primary combustion chamber is oriented substantially vertically, the cross section of the primary combustion chamber is gradually reduced downward, and the lowermost end of the primary combustion chamber is the secondary combustion chamber The waste disposal apparatus according to any one of claims 1 to 3, wherein the dropping port communicating with a combustion chamber is formed.   2. The waste treatment apparatus according to claim 1, wherein the lowermost end portion of the primary combustion chamber is reduced in diameter to a conical shape so as to prevent free fall of the waste charged into the primary combustion chamber.   The waste treatment apparatus according to claim 5, wherein the air injection device and the burner device are arranged in the conical reduced diameter portion and inject an air jet and fuel toward the center of the reduced diameter portion.   The waste treatment apparatus according to claim 5 or 6, wherein the air injection device includes a plurality of air injection nozzles arranged at predetermined angular intervals in a circumferential direction of the primary combustion chamber.   The waste treatment apparatus according to claim 2, wherein the air injection ports are arranged on the furnace wall surface at equal intervals in the furnace axis direction.   The waste disposal apparatus according to claim 8, wherein a planar position of the air injection port is set to a position facing the burner apparatus.   The maintenance burner device that operates when the waste is not charged and raises the furnace temperature of the primary combustion chamber to a temperature of 1000 ° C. or more is disposed in the primary combustion chamber. The waste disposal apparatus according to any one of 1 to 9. A waste treatment apparatus comprising a vertical primary combustion chamber capable of throwing in difficult-to-separate waste, and a secondary combustion chamber for primary combustion in the primary combustion chamber and gasification of the waste that falls from the primary combustion chamber. In the disposal method of infectious waste using
The amount of waste accumulated in the primary combustion chamber is regulated within a range of 0.5 to 2 times the waste treatment amount / time during steady operation of the primary combustion chamber. Waste is thrown into the primary combustion chamber from above,
The lowermost part of the waste is burnt by the fuel supply and the air jet of the burner device and the air injection device arranged at the lowermost part of the primary combustion chamber, and the dry jet combustion of the waste accumulated in the primary combustion chamber is carried out by the air jet A method for disposing of infectious waste, which is caused to proceed by air. A waste treatment apparatus comprising a vertical primary combustion chamber capable of throwing in difficult-to-separate waste, and a secondary combustion chamber for primary combustion in the primary combustion chamber and gasification of the waste that falls from the primary combustion chamber. In the disposal method of infectious waste using
The amount of waste accumulated in the primary combustion chamber is regulated within a range of 0.5 to 2 times the waste treatment amount / time during steady operation of the primary combustion chamber. Waste is thrown into the primary combustion chamber from above,
An air flow is jetted from the wall surface of the furnace on the side surface of the waste accumulated in the furnace area, and a combustion reaction between the air flow and the waste is locally advanced, and the upper region of the waste and the secondary A method for disposing of infectious waste, characterized in that a longitudinal flow path that communicates with the combustion chamber is formed in the waste. The waste treatment method according to claim 12, wherein dry distillation combustion of the waste accumulated in the primary combustion chamber is advanced by air of the air flow.

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