JPH0674433A - Incinerating device for waste refuse - Google Patents

Abstract

PURPOSE:To use a simple structure to feed waste to the central part of a hearth and stabilize the combustion. CONSTITUTION:At an upper part of the body of a device 10 a preheating chamber 30 which extends to the periphery of the body and communicates with a combustion chamber 12 is provided. An air-feeding pipe 33 for feeding air from the combustion into the preheating chamber 30 is provided. A preheating tube 40 extending toward the same direction as the preheating chamber 30 is provided inside the preheating chamber. The forward end of this preheating tube 40 opens into the combustion chamber 12. In the center of the combustion chamber 12 a cylindrical exhaust tube 20 for discharging the exhaust gases from the combustion upward and having the bottom end opening into the lower part of the combustion chamber 12 is provided. Waste to be burnt D' is fed into the combustion chamber 12 through the preheating tube 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste incinerator for municipal solid waste.

[0002]

2. Description of the Related Art At present, the amount of industrial waste in Japan is 292 million tons of industrial waste and 43 million tons of general waste, which is an enormous amount, and the amount tends to increase year by year. . These wastes are treated by landfill, dumping in ocean, incineration, etc., but the types of waste suitable for landfill are limited, and the treatment cost is rising due to depletion of landfill. In addition, most of the waste is currently incinerated for the reason that ocean dumping is not so preferable for environmental protection. At the same time, effective utilization of heat energy by incineration of waste is being reviewed.

Therefore, first, a typical incinerator at present will be described with reference to FIGS. 3 and 4. FIG. 3 is a schematic sectional view showing an example of a fixed bed (stalker type) incinerator. As shown in this figure, the fixed bed incinerator 1a is
The first grate 3a, the second grate 3a ', and the third grate 3 as fixed beds provided on the bottom in a stepwise downward manner
a first combustion chamber 2a having a '' and a charging hopper 4a serving as a dust supply device for charging dust into the combustion chamber 2a
And a second combustion chamber 2a 'following the first combustion chamber 2a.

A dry zone is formed above the first grate 3a, a combustion zone is formed above the second grate 3a ', and a post-combustion zone is formed above the third grate 3a''. Are formed.

Then, the waste is first introduced into the first grate 3a in the first combustion chamber 2a from the charging hopper 4a, is dried by obtaining the reflux of the combustion exhaust gas in the drying zone above it, and is then the second grate. In the upper combustion zone of 3a ', main combustion is performed in full-scale, and the remaining unburned components are completely incinerated in the post combustion zone of the last third grate 3a''. The combustion gas is guided to the second combustion chamber 2a ', where complete combustion is performed.

The ash after burning is the grate 3a, 3a ', 3
It is dropped in each hopper provided at the bottom of a ″. A burner 5a is provided on the side wall of the combustion chamber 2a in order to assist the self-combustion of dust, and an air introduction part 6 is provided above the burner 5a.
a is provided.

In this way, the grate is divided into three stages, and the respective combustion zones on the grate are divided into the functions of drying, combustion, and post-combustion, and the second combustion chamber 2a 'is provided, thereby forming waste. It is designed to handle various combustible materials.

Next, FIG. 4 is a schematic sectional view illustrating a fluidized bed incinerator. As shown in this figure, in the case of the fluidized bed type, the incinerator 1b is a cylindrical freeboard combustion chamber 2b.
And the dust supply device 4b provided on the side wall thereof and the combustion chamber 2b
Basically, a mortar-shaped air diffuser plate 3b having a large number of vent holes provided at the bottom of the air conditioner, and a fluid medium circulation device 7b for circulating sand as a fluid medium from the bottom of the air diffuser plate 3b to the dust supply device 4b. It is configured.

Then, the air introducing portion 6 below the diffuser plate 3b.
When air is introduced from b, the air is supplied to the sand above it through the diffuser plate 3b and the burner 5b is ignited, and dust is supplied from the dust supply device 4b into the combustion chamber 2b in this state, the sand A fluidized bed is formed by the flow of the above, and the waste is well agitated and satisfactorily combusted in this fluidized bed, and the generated combustion exhaust gas is discharged from the upper part of the combustion chamber 2b to the waste heat boiler of the next step. The sand is circulated and used by the fluidized medium circulating device 7b.

In such a fluidized bed type incinerator 1b, the reaction speed is very fast because the waste is agitated in the combustion chamber 2b by the fluidized bed, and the waste is instantly decomposed into gas and burned well. It has superior features for garbage compared to the fixed bed type incinerator 1a.

[0011]

By the way, since combustible waste is a mixture of combustible wastes having different combustion characteristics, its combustion control is extremely difficult, and it is said that various improvements have been made, but there are many problems. Have a point.

[0012] That is, the requirements for an excellent incinerator are to be able to continuously supply the waste evenly, and to appropriately adjust the amount of dust according to the change in the quality of the waste and the combustion condition in the furnace. It is possible to burn, the amount of fly ash is small, the structure is simple and there are few failures, and the amount of water contained in garbage is small and it can be burned easily.

Looking at the conventional fixed bed type incinerator 1a in light of these requirements, it is impossible to adjust the burning rate different depending on the type of waste. Complete combustion has already been performed in the dry zone, and a so-called blow-through phenomenon occurs. In addition, when plastic or the like is heated, it becomes a nodule, and a blow-through phenomenon similar to the above occurs. In addition, the processing capacity is large and the structure is relatively complicated for the processing capacity.
It's hard to say that all of ,,, and are excellent.

On the other hand, a fluidized bed type incinerator 1b
Since the waste is well agitated in the combustion chamber 2b, the combustion instantly occurs and the combustion efficiency is good, but it is necessary to disperse the waste in the combustion chamber as uniformly as possible and to supply the waste. 7b is essential, the structure is complicated, and as a result, the construction cost is increased and the frequency of failures is increased.

In the conventional incinerator, there is no incinerator configured to suppress the amount of fly ash formed by the fine ash particles generated in the combustion process soaring.
If there is a large amount of fly ash, this fly ash adheres to the heat transfer tubes of the boiler that uses the subsequent exhaust gas, blocking the gas passage,
There are many inconveniences such as deterioration of heat transfer efficiency.

The present invention has been made in order to solve the above problems and ensures stable combustion in the combustion equipment, and as a result, the emission of harmful substances can be appropriately suppressed. Moreover, it is an object of the present invention to provide a waste incinerator that can reduce the amount of fly ash, and has a simple structure and can be constructed at low cost.

[0017]

A waste incinerator according to the present invention is provided with a cylindrical vertical incinerator body having a combustion chamber formed therein, and waste is introduced from the upper part of the body. In the incinerator of waste, which is configured so that the input waste is burned in the device body, the combustion exhaust gas is discharged from the upper part of the device body, and the combustion residue is extracted from the lower part of the device body. In the upper part of the apparatus main body, a preheating chamber set so that the direction of the flow path deviates from the center of the combustion chamber is provided in communication with the combustion chamber, and an air introduction pipe for introducing combustion air into the preheating chamber is provided. A preheating pipe is provided in the preheating chamber in a direction in which the preheating chamber extends, the tip of the preheating pipe is opened to face the combustion chamber, and waste is introduced into the combustion chamber through the preheating pipe. It is configured to It is intended to.

[0018]

According to the waste incineration system of the present invention, since the waste is introduced into the combustion chamber through the preheating pipe, the waste is preheated while passing through the preheating pipe. It is preheated by receiving heat from the waste, the waste is dried before being put into the combustion chamber, and a part of it is thermally decomposed and gasified, and is already introduced into the combustion chamber in a state where it is extremely easy to burn.
Stable combustion in the combustion chamber.

Further, the preheating chamber is provided so that the direction of the flow path is deviated from the center of the combustion chamber, and an air introducing pipe for introducing combustion air is arranged in the preheating chamber. Therefore, the air supplied from the air introduction pipe into the combustion chamber makes a circular motion along the inner peripheral wall of the combustion chamber, and the gas in the combustion chamber, including the exhaust gas, undergoes a circular motion as a result of the circular motion. Therefore, the fly ash generated by burning the waste is captured by the inner peripheral wall of the combustion chamber by the cyclone effect due to the centrifugal force and can be prevented from being discharged to the outside of the combustion chamber.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic side sectional view showing an example of a waste combustion apparatus according to the present invention. As shown in this figure, the apparatus body 10 of the combustion apparatus is composed of a vertically long cylindrical body, and a mortar-shaped hearth portion 11 narrowed toward the center is formed in the lower portion thereof. Inside the apparatus main body 10, a cylindrical discharge pipe 20 extending vertically is provided so as to share the center line thereof. The discharge pipe 20 penetrates the ceiling 13 of the apparatus main body 10 and is guided to the outside of the system, and the lower end of the discharge pipe 20 is opened so that the hearth 1
Facing one. A doughnut-shaped combustion chamber 12 in a plan view is formed between the outer peripheral surface of the discharge pipe 20 and the inner peripheral surface of the apparatus body 10.

A combustion residue discharge mechanism 70 is provided at the bottom of the apparatus body 10. The discharge mechanism 70 is composed of a discharge pipe 71 having an opening 72 in the upper portion, and a third pusher 73 that closely reciprocates on the inner wall surface of the discharge pipe 71. The pusher 73 is driven by a driving mechanism (not shown), and the reciprocating motion causes the device body 1 to move.
The combustion residue accumulated in the bottom portion of 0 is led out to the outside through the discharge pipe 71.

A predetermined number of nozzles 14 for introducing secondary air are provided on the inner wall surface of the hearth part 11.
An air introduction pipe 15 arranged on the outer peripheral portion of the hearth 11 is connected to the nozzle 14.

As shown in FIG. 2, a preheating chamber 30 is provided on the upper side of the apparatus main body 10 in such a state that the direction of the flow path is deviated from the center of the combustion chamber 12. In particular,
The preheating chamber 3 is extended so as to extend tangentially to the outer periphery of the apparatus body 10.
0 is provided, and the preheating chamber 30 communicates with the combustion chamber 12. And, the ceiling portion 31 of the preheating chamber 30 is provided with an appropriate number of nozzles 32 for supplying combustion air,
Air introduction pipe 3 for introducing combustion air into these nozzles 32
3 is arranged outside the preheating chamber 30. A predetermined number of nozzles 32 are also provided on the ceiling 13 of the combustion chamber 12. From these nozzles 32, primary air for burning the waste that has been introduced into the combustion chamber 12 is introduced.

A burner 35 is provided on the lower wall surface 34 of the preheating chamber 30. By igniting the burner 35, the burner 35 is used for initial combustion of the waste introduced into the combustion chamber 12 and used for controlling the temperature in the combustion chamber 12 when the combustion reaches a steady state.

A preheating tube 40 is provided in the preheating chamber 30 in the direction in which it extends. This preheating tube 40
Has a rectangular cross section, and the length of one side of this rectangle is set to at least 1 m or more in this embodiment.
Further, the front end portion of the preheating pipe 40 is opened toward the combustion chamber 12, and a waste input port 41 is formed by this opening.

A projecting portion 42 projecting outward from the preheating chamber 30 is formed at the base end portion of the preheating tube 40, and an opening 51 is provided in the upper wall portion of the projecting portion 42.
A waste communication path 50 is connected to the opening 51.

Inside the protrusion 42, a first pusher 60 is provided which is in close contact with the inner wall surface of the protrusion 42 so as to have a sealing effect and reciprocates in the protrusion 42 at least within the size range of the opening 51. Has been. The pusher 60 is configured to perform the above-mentioned reciprocating movement by driving a driving device (not shown).

The communication passage 50 has a horizontal portion 54 formed by rising slightly vertically from the protrusion 42 and then horizontally bending. An opening 52 is also provided on the upper surface of the horizontal portion 54, and a hopper 53 for storing waste is provided above the opening 52 so as to communicate with the opening 52. A second pusher 55 that reciprocates in close contact with the inner wall surface so as to have a sealing effect is also provided in the horizontal portion 54.
Is also driven by a driving device (not shown).

Since the waste combustor of this embodiment is constructed as described above, when the second pusher 55 is reciprocated, when the pusher 55 is retracted and the opening 52 of the hopper 53 is opened, the hopper is opened. The waste D stored in 53 falls into the horizontal portion 54 of the communication passage 50, and when the pusher 55 advances, the fallen waste D is pushed by this and advances. At this time, if the drive of the first pusher 60 is synchronized with the drive of the second pusher 55 so as to move in the opposite directions, the waste D that has moved forward in the horizontal portion 54 will have an opening at the bottom of the communication passage 50. It falls into the protrusion 42 of the preheating pipe 40 via 51.

The dropped waste D is then pushed out into the preheating pipe 40 by the advance of the first pusher 60, and the waste already inserted in the preheating pipe 40 is pushed in a bead type to discard the tip thereof. The material is dropped into the holder from the material input port 41 and used for combustion. As described above, the second pusher 55 and the first pusher 60 alternately reciprocate, so that the waste D in the hopper 53 eventually pulsates in sequence through the preheating pipe 40 to the combustion chamber of the apparatus body 10. 12 will be supplied. In this case, since the pushers 55 and 60 having the sealing effect alternately reciprocate, the so-called blow-through phenomenon in which the inside of the combustion chamber 12 and the inside of the hopper 53 are in communication does not occur.

The hopper 53, the communication passage 50, the second pusher 55, the protruding portion 42 of the preheating pipe 40, and the first pusher 60 constitute a waste insertion mechanism for inserting waste into the preheating pipe. ing.

The inside of the preheating pipe 40 has been heated by the burner 35 and the heat from the inside of the combustion chamber 12 has been reached to reach a considerably high temperature. Due to this high temperature, a decomposition zone of the waste D inserted into the preheating pipe 40. Are formed. Therefore, the waste D moving sequentially in this decomposition zone is heated, and as the drying progresses, a part of the waste D becomes gasified and is in a state suitable for combustion.
Falls into the hearth 11 at the bottom of the and burns.

In this embodiment, the temperature of the decomposition zone is set to 300 ° C to 500 ° C. Regarding how much waste D is treated in this decomposition zone,
In addition to the temperature of the decomposition zone, it is affected by the moving speed of the waste D in the preheating pipe 40. Usually, the decomposition zone is treated so that gasification is started. In addition,
Waste D usually gives an oily product at 500 ° C. to 550 ° C., and when it reaches 900 ° C., combustion is completed, but in the decomposition zone, no further processing is performed. The temperature of the decomposition zone can be controlled by adjusting the amount of primary air supplied to the preheating chamber 30 from the nozzle 32 provided in the ceiling portion 31.

The partially gasified waste D'falls from the waste input port 41 and reaches the hearth portion 11 of the combustion chamber 12, where it is burned in earnest. At this time, the preheating chamber 30 Since the primary air is supplied from the nozzles 32 provided in the ceiling portion 31, an air flow that rotates clockwise in FIG. 2 is generated in the combustion chamber 12, and the fine fly ash generated by the combustion is a circle of this air flow. A centrifugal force is applied by the motion, and the centrifugal force is applied to the inner wall surface of the combustion chamber 12 by the so-called cyclone effect. Therefore, the combustion exhaust gas is discharged to the outside of the system through the exhaust pipe 20, but the amount of fly ash in this exhaust gas is considerably suppressed. In this example, the amount of fly ash contained in the exhaust gas at the outlet of the discharge pipe 20 could be reduced by about 80% as compared with the conventional incinerator.

The nozzle 14 provided in the hearth 11
Since the secondary air is supplied from the above, the waste D ″ thrown into the combustion chamber 12 can be more completely burned more effectively, and the amount of fly ash generated by the supply of the secondary air. However, as described above, since an air current that makes a circular motion is generated in the combustion chamber 12, the fly ash is effectively captured by the centrifugal force of the air current.

The combustion residue accumulated in the hearth 11 can be discharged to the outside of the system by appropriately reciprocating the third pusher 73 in the discharge pipe 71.

Although only the waste is normally loaded in the hopper 53, if the waste is extremely difficult to burn or if it is desired to positively control the temperature in the combustion chamber 12 to be constant. May mix coal in the waste D. Combustion in the combustion chamber 12 can be stabilized by adjusting the mixing amount of this coal.
In the present example, the lump coal crushed to 50 mm or less was appropriately mixed, but it was possible to solve the problem of preventing the fluctuation of the calorific value and supplementing the calorific value without any problem.

As described above, in the combustion apparatus of the present invention, the preheating chamber 30 is attached to the apparatus main body 10, the preheating tube 40 is arranged in the preheating chamber 30, and the apparatus main body 1 is inserted through the preheating tube 40.
Since the waste is introduced into the combustion chamber 12 of No. 0, the waste is first preheated and dried in the preheating pipe 40, and a part of the waste is gasified to be suitable for combustion. It is introduced into 12 and can burn very efficiently therein.

Moreover, since fly ash is captured on the inner peripheral wall of the combustion chamber 12 by the cyclone effect, the fly ash discharged along with the exhaust gas is extremely small, and the fly ash to the heat transfer tube of the subsequent boiler is reduced. Adhesion is drastically reduced and corrosion of the heat transfer tube is effectively suppressed.

Furthermore, the operation of the above-mentioned waste insertion mechanism is appropriately performed to control the amount of the waste D'charged into the combustion chamber 12,
Primary air supplied from the air introduction pipe 33 or the air introduction pipe 1
It is possible to properly control the temperature in the combustion chamber 12 by adjusting the amount of secondary air supplied from No. 5, and a very stable combustion state is realized.

From the above, by adopting the incinerator of the present invention, it is possible to realize the extremely difficult burning treatment of municipal solid waste, which is originally extremely difficult.
Combustion control is performed under conditions where no harmful substances are generated, and it can be easily and completely performed under thorough control, which is extremely beneficial for environmental protection.

[0042]

As described above, since the waste incinerator of the present invention is configured to introduce the waste into the combustion chamber through the preheating pipe in the preheating chamber continuing to the combustion chamber, the waste is incinerated. Is preheated by receiving heat from the preheating chamber while passing through the preheating tube, and the waste is dried and partly pyrolyzed and gasified before being put into the combustion chamber, which is extremely easy to burn. It is suitable for being introduced into the combustion chamber in such a state that it stably burns in the combustion chamber and performing combustion management.

Further, the preheating chamber is provided so that the direction of the flow path is deviated from the center of the combustion chamber, and an air introducing pipe for introducing combustion air is arranged in the preheating chamber. Therefore, the air supplied from the air introduction pipe into the combustion chamber makes a circular motion along the inner peripheral wall of the combustion chamber, and the gas in the combustion chamber, including the exhaust gas, undergoes a circular motion as a result of the circular motion. Therefore, the fly ash generated by burning the waste is captured by the cyclone effect of the centrifugal force on the inner peripheral wall of the combustion chamber and can be prevented from being discharged to the outside of the combustion chamber. Can be effectively prevented.

If a waste insertion mechanism for inserting waste into the preheating pipe is provided, it is possible to properly operate this insertion mechanism to adjust the amount of waste supplied to the combustion chamber, It is convenient that the above-mentioned adjustment is performed according to the type of waste to appropriately control the combustion state of the waste in the combustion chamber.

Furthermore, if coal is mixed with the waste, the calorific value due to combustion in the combustion chamber can be controlled by adjusting the amount of coal mixed according to the type of waste, Temperature control becomes easy.

In addition, since the structure is simple, it can be constructed at a relatively low cost and is economically advantageous.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional side view showing an example of a waste combustion apparatus according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a schematic cross-sectional view showing an example of a conventional fixed bed type refuse incinerator.

FIG. 4 is a schematic cross-sectional view showing an example of a conventional fluidized bed waste incinerator.

[Explanation of symbols]

 10 Device Main Body 11 Furnace Floor 12 Combustion Chamber 13, 31 Ceiling 14, 32 Nozzle 15 Secondary Air Introducing Pipe 20 Exhaust Pipe 30 Preheating Chamber 33 Primary Air Introducing Pipe 34 Lower Wall 35 Burner 40 Preheating Pipe 41 Waste Inlet 42 Projection portion 50 Communication passage 53 Hopper 55 Second pusher 60 First pusher 70 Discharge mechanism 73 Third pusher

Claims (1)

[Claims] 1. A cylindrical vertical incinerator body having a combustion chamber formed therein is provided, waste is thrown in from the upper part of the apparatus body, and the thrown waste is burned in the apparatus body. , The combustion exhaust gas is discharged from the upper part of the device body,
In a waste incinerator configured such that the combustion residue is extracted from the lower part of the device body, a preheating chamber set so that the direction of the flow path deviates from the center of the combustion chamber in the upper part of the device body. Provided in communication with the combustion chamber, an air introduction pipe for introducing combustion air is arranged in the preheating chamber,
A preheating pipe is provided in the preheating chamber in a direction in which the preheating chamber extends, a tip portion of the preheating pipe is opened so as to face the combustion chamber, and waste is introduced into the combustion chamber through the preheating pipe. Incinerator for waste, which is characterized by being