JPH10185142A - Method and device for secondary incineration of flue gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method and device for secondary incineration of flue gas by which toxic materials included in the flue gas generated when waste is incinerated can be substantially completely incinerated, removed or detoxified and only clean flue gas can be exhausted. SOLUTION: Fuel such as waste oil 18 stored in a fuel groove 16 formed on the bottom part of a cylindrical combustion chamber 12 is ignited with the flame of a burner 34, and vaporizing air heated through a fuel vaporizing nozzle 32 is sprayed to the ignited waste oil 18 to generate air flow turning in the combustion chamber 12 so that the vaporization and combustion of the waste oil 18 are accelerated. Combustion air is introduced into the combustion chamber 12 through air discharge holes 28 formed on the vertical part 23 of an air duct 22 to accelerate the combustion of the waste oil 18, and raise and maintain combustion temperature at 1500 to 1600 deg.C. Flue gas to be treated is introduced into the combustion chamber 12 in which the waste oil 18 is burnt to incinerate toxic materials, in the flue gas, to remove or detoxify the incinerated toxic materials and then exhaust the detoxified flue gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to remove or detoxify harmful substances contained in flue gas generated when rubber, plastics and other wastes are incinerated and discharge them.
More particularly, the present invention relates to a method and an apparatus for secondary incineration of flue gas, and more particularly, to a method and an apparatus for incinerators, boilers and other apparatuses equipped with combustion chambers (herein, these are collectively referred to as "incinerators"). , Discarded tires, plastics,
Uses smoke emitted from incineration of various resin products such as paints, other industrial waste, and various types of garbage discharged from general households as fuel, especially for automobiles and other various machinery and equipment. Lubricating oil (hereinafter referred to as “waste oil”) discarded due to replacement of engine oil, transmission oil or the like, introduced into a combustion chamber where high temperature is burned, and incinerated to be colorless, odorless and harmless. The present invention relates to a method and an apparatus for secondary incineration of flue gas for discharging smoke.

[0002]

2. Description of the Related Art When various types of waste are incinerated, dusts such as soot and various cinders, odors, and harmful substances generated by the incineration are mixed with flue gas and released to the atmosphere, which causes pollution. I have.

[0003] In particular, in addition to the above-mentioned dust and odor, carbon monoxide, hydrocarbons, nitrogen oxides, and the like are contained in the smoke emitted when incinerating discarded tires, plastics, paints, and various other resin products. It contains various harmful substances such as sulfur oxides, hydrogen chloride, and dioxin. If the flue gas containing such various harmful substances is directly released to the atmosphere, air pollution and environmental destruction are inevitable. Above all, the emission of particularly toxic harmful substances such as dioxins known as carcinogens causes cancer, causes malformation of animals and plants, and causes polluting diseases. Should. For this reason, methods for removing such harmful substances from flue gas have been conventionally sought.

In order to remove such harmful substances,
By injecting a water stream into the flue gas and supplying a mixture of air and a petroleum fuel such as kerosene or heavy oil into the incinerator, or a device configured to be able to adsorb harmful substances in the flue gas by the water stream. An incinerator having a structure in which waste is burned at a temperature of 700 to 800 ° C. together with waste has been proposed.

[0005] It should be noted that used automobile engine oil,
The flash point of other waste oils such as lubricating oil is 130-300 ° C
And it cannot be used as a fuel itself, so it is either mixed with other waste, or incinerated in an incinerator, etc., and discarded, or mixed with fuel with a low flash point, etc. It has been proposed to use it as a fuel.

[0006]

SUMMARY OF THE INVENTION Among the above conventional devices,
For equipment that injects a stream of water into the flue gas, the type of harmful substances that can be adsorbed and removed by water, even if the flue gas can be made colorless and transparent by removing soot, dust, and odors in the flue gas Is limited and cannot remove all of the harmful substances in flue gas. In addition, it is conceivable to inject an aqueous solution containing various chemicals into flue gas for the purpose of removing various kinds of harmful substances. However, the mixing of expensive chemicals results in an increase in incineration costs of wastes and the like.

[0007] Furthermore, water and various chemical aqueous solutions that adsorb soot, dust, foul odors and some other harmful substances in the flue gas can be drained as they are into rivers and the like, if they are drained into rivers and the like, the water pollution and water quality of the rivers and the like will increase. Since it causes pollution, it cannot be drained as it is, and in order to drain the water or the aqueous solution, equipment for purifying the water or the aqueous solution or neutralizing chemicals in the aqueous solution is required. This necessitates an increase in the size of the device and increases the cost required for operating the device.

On the other hand, in a conventional incinerator that burns waste together with fuel such as kerosene or heavy oil mixed with air,
Since the combustion of the waste is performed at a temperature of about 800 ° C., the chlorine compound contained in the waste is combined with other substances, thereby promoting the generation of dioxin.

In this type of incinerator, a secondary incinerator is provided in the flue or in communication with the incinerator for incinerating the waste, in order to purify the smoke discharged from the incinerator. ,
There is also a device equipped with a burner that uses kerosene, heavy oil, gas, etc. as fuel for introducing smoke into this secondary incineration chamber and heating the smoke in the flue or in the secondary incineration chamber for secondary incineration. However, since the combustion temperature of the burner is about 900 ° C., even if it is possible to burn some harmful substances such as carbon monoxide, hydrocarbons, soot, and foul odor to make the exhaust gas colorless and odorless, It is not possible to detoxify highly toxic harmful substances, such as dioxins, that are decomposed for the first time by high temperatures of over ℃.

[0010] As described above, in the above-described apparatus in which an auxiliary fuel such as kerosene, heavy oil, or gas is used when burning waste, and smoke is burned by a burner, kerosene, heavy oil, etc. In addition, the cost for incineration of waste increases in that fuel such as gas is used, but the above-mentioned waste oil has a high flash point, and therefore cannot be used alone as a fuel to replace the kerosene or heavy oil.

Therefore, an object of the present invention is to provide an incinerator capable of burning almost all harmful substances contained in flue gas from 1500 to 1500.
It is an object of the present invention to provide a method and an apparatus for secondary incineration of flue gas which can generate a combustion temperature as high as 600 ° C.
By generating a waste oil, which has been discarded without being used as a fuel alone, as a fuel at a high combustion temperature of 500 to 1600 ° C., the cost of secondary combustion of flue gas is reduced as much as possible. The purpose is to reduce.

[0012]

In order to achieve the above object, the secondary incineration method of smoke exhaust according to the present invention is directed to a method for incinerating various resin products such as discarded tires, plastics and paints, and other wastes. In the method of secondary incineration of smoke generated at the time of incineration and incineration of harmful substances in the smoke exhaust, in the case of petroleum fuel such as heavy oil supplied to the combustion space, preferably waste oil such as engine oil of discarded automobiles The fuel is ignited, and vaporized air is sprayed on the ignited fuel to promote the vaporization and combustion of the fuel. Further, the combustion air is introduced into the combustion space, and the fuel is injected into the combustion space. Is burned at a combustion temperature of 1500 to 1600 ° C., and the flue gas to be subjected to secondary incineration is introduced into the combustion space, and the harmful substances in the flue gas are incinerated by burning the fuel. Is discharged.

[0013] More preferably, the air blown to the ignited fuel is blown at an angle to the surface of the fuel to create an airflow swirling in the combustion space.

[0014] More preferably, the air blown against the fuel is heated in the combustion space before spraying the fuel.

Further, the secondary smoke incineration apparatus of the present invention introduces the smoke exhaust generated during the incineration of waste into a combustion chamber formed inside, and the introduced smoke is subjected to secondary incineration. In a device to be discharged later, a combustion chamber 12 formed by covering upper and lower openings of a cylindrical side wall with a wall body, and a combustion chamber 1
And a vertical section 23 disposed on the center line of the second section 2, a blower pipe 22 having a large number of air discharge holes 28 formed on a peripheral side surface of the vertical section 23, and connected to the blower pipe 22 so that the inside of the combustion chamber 12 An air supply means such as a blower 24 for supplying combustion air; and a combustion chamber 12 formed on a bottom wall surface in the combustion chamber 12.
Fuel groove 1 for storing fuel such as waste oil 18 supplied from outside
6, a fuel ignition means such as a burner 34 disposed on the fuel stored in the fuel groove 16 with the front end thereof facing the fuel, and discharges vaporized air toward the fuel 18 stored in the fuel groove 16. And a flue 14 for introducing flue gas which has one end communicating with the combustion chamber 12 and the other end communicating with an incinerator 50 for incinerating waste.

In the secondary smoke incinerator, the tip 33 of the fuel vaporizing nozzle 32 may be arranged to be inclined in the circumferential direction of the combustion chamber 12. Is connected to the blower tube 22 so that air introduced through the blower tube 22 is
Can be applied.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the overall configuration of an incinerator in which a secondary smoke incinerator according to the present invention is attached to an incinerator 50, and 10 shows a secondary smoke incinerator according to the present invention. . As shown in FIG. 2, the secondary incinerator 10 for smoke exhaust includes a combustion chamber 12 formed by closing upper and lower openings of a cylindrical wall with a disk-shaped wall. A flue 14 having one end communicating with the combustion chamber 12 and the other end communicating with the incinerator 50 is provided, and the smoke generated when the waste is incinerated by the incinerator 50 is discharged from the flue. It is configured to be able to be introduced into the combustion chamber 12 of the secondary incinerator 10 of the above-mentioned exhaust gas via the exhaust pipe 14. The flue 14 can be connected to the outer periphery of the cylindrical side wall of the combustion chamber 12 so as to communicate with the combustion chamber 12, but in the present embodiment, the combustion is performed by penetrating the bottom wall of the combustion chamber 12. A configuration in which one open end protrudes into the chamber 12 so that the smoke exhaust introduced into the combustion chamber 12 can be suitably diffused into the combustion chamber 12 by an air flow described later swirling in the combustion chamber 12. doing.

The flue 14 is formed in a cylindrical shape having a diameter of preferably about half the bottom shape of the combustion chamber 12, and in the present embodiment, the flue 1 formed in a cylindrical shape is used.
4 is slightly projected into the combustion chamber 12 so that the projection 15
An endless annular groove 16 is formed by the bottom wall of the combustion chamber 12, the protrusion 15 of the flue, and the side wall of the combustion chamber 12, and the fuel burning in the combustion chamber 12 is formed in the groove 16. It is configured so that it can be stored.

As this fuel, various liquid fuels such as kerosene, light oil, heavy oil and the like can be used. However, among the fuels having a relatively low flash point such as the above-mentioned kerosene and light oil, a large amount of fuel having a high combustion rate is used. It is preferable to use heavy oil in the fuel because it is consumed. In the present embodiment, furthermore, in order to reduce the cost of the secondary combustion of the flue gas as much as possible, the engine oil, the transmission oil, and the like of the automobile, which are discarded by the replacement which is itself a waste. Waste oil obtained by collecting lubricating oil such as machine oil is used as fuel.

On the side wall of the combustion chamber 12 formed in a cylindrical shape, there is provided a chimney 20 which communicates with the combustion chamber 12 and discharges to the atmosphere exhausted smoke which is burned and detoxified in the combustion chamber 12.
In this embodiment, the mobile phone protrudes in a direction orthogonal to the wall surface, and then extends upward.

Further, the combustion chamber 1 has a combustion chamber 1 therein.
An air blower pipe 22 for introducing combustion air is inserted into the inside 2, and in the present embodiment, the blower air is blown from the upper outer periphery of the cylindrical wall surface to the center of the combustion chamber 12 at right angles to the wall surface. The pipe 22 is inserted, and the blower pipe 22 is
A vertical portion 23 is formed by bending and hanging downward at the center of the combustion chamber 12.
It is directed toward the center of the projecting portion 15 of the flue 14 projecting inside. A blower 24 is connected to the other end of the blower tube 22 so that the blower 24 and the blower tube 22 can introduce combustion air into the combustion chamber 12.

At the vertical portion 23 of the air duct 22, which is directed toward the center of the projecting portion 15 of the flue 14,
An inverted conical flow dividing plate 26 closing the opening at the end of the vertical portion 23 of the blower tube 22 is fixed, and the exhaust gas introduced into the combustion chamber 12 through the flue 14 is supplied to the flow dividing plate 26. It is configured such that it can collide and diffuse uniformly in the combustion chamber 12.

A large number of air discharge holes 28 are formed in the peripheral portion of the vertical portion 23 of the blower tube 22 whose front end opening facing the flue 14 is closed. Combustion air can be uniformly introduced into the combustion chamber 12 through the hole 28, and the air discharged from the air discharge hole 28 generates air convection to promote the combustion of the fuel 18 in the combustion chamber 12. To increase the combustion temperature.

Slightly above the endless annular fuel groove 16 formed at the bottom of the combustion chamber 12, there is a fuel pipe 30 which penetrates the cylindrical wall of the combustion chamber 12 and supplies fuel into the combustion chamber 12.
The other end of the fuel pipe 30 is communicated with a fuel tank 38 provided outside the combustion chamber 12 so that the fuel groove 16 can be supplied with waste oil 18 as fuel. I have.

A vertical portion 23 of the blower tube 22, which is slightly above the flow dividing plate 26, communicates with the blower tube 22 at a base end thereof. In the present embodiment, four fuel vaporizing nozzles 32 projecting radially are provided in the orthogonal direction, and a tip 33 of the fuel vaporizing nozzle 32 is formed on a bottom wall of the combustion chamber 12 by a fuel. Bending toward the groove 16, the fuel vaporized air is blown to the waste oil 18 in the fuel groove 16 through the blower pipe 22 and the fuel vaporization nozzle 32 to vaporize the fuel, and the air necessary for the combustion of the waste oil 18 is removed. It is designed to be sprayed directly on the fuel.

The tip 33 of the fuel vaporizing nozzle 32 can be disposed at an angle to the surface of the waste oil 18 stored in the fuel groove 16. The tip 33 of the nozzle 32 is inclined by about 60 ° in a clockwise direction on the circumference around the protrusion 15 of the flue 14 as shown in FIG. It is configured such that an airflow swirling clockwise in FIG. 3 in the combustion chamber 12 is generated.

The tip of the burner 34 penetrating through the cylindrical wall surface is disposed so as to face the waste oil 18 stored in the fuel groove 16, and the flame injected by the burner 34 causes the fuel groove 16 to enter the fuel groove 16. It is configured so that the accumulated waste oil 18 can be ignited.

In the present embodiment, the burner 34 is configured to be able to inject kerosene mixed with compressed air from the tip thereof.
Numeral 4 is not particularly limited to a burner using kerosene, but may be a fuel oil, a gas, or another fuel as long as it can heat a waste oil 18 such as an engine oil having a high flash point. . When a fuel having a low flash point is used instead of the waste oil, a simpler ignition means can be used instead of the burner 34.

The method of using the secondary smoke incinerator 10 of the present invention constructed as described above will be described, and the secondary smoke incineration method will be described. First, the pump provided in the fuel pipe 30 will be described. The waste oil 18 is supplied into the fuel groove 16 formed at the bottom of the combustion chamber 12 by driving the fuel tank 18.

Thereafter, a flame is injected from a burner 34 disposed above the fuel groove 16 slightly above the fuel groove 16 at a position above the waste oil 18 in the fuel groove 16 to heat the waste oil 18 in the fuel groove 16. Evaporate and burn.

The flame is injected by the burner 34 in an auxiliary manner to ignite the waste oil 18 having a high flash point. After the ignition of the waste oil 18, the injection of fuel such as kerosene by the burner 34 is stopped. You can also.

After the waste oil 18 is ignited by the burner 34, the blower 24 connected to the blower pipe 22 is driven to introduce combustion air into the combustion chamber 12.

The combustion air introduced into the combustion chamber 12 through the ventilation pipe 22 is uniformly distributed in the combustion chamber 12 through a number of air discharge holes 28 opened in the vertical portion 23 of the ventilation pipe 22. At the same time, the waste oil 18 is emitted as vaporized air for vaporizing the waste oil 18 toward the ignited waste oil 18 from the tip 33 of the fuel vaporization nozzle 32 projecting from the tip of the blower tube 22.

The tip 33 of the fuel vaporizing nozzle 32 is inclined at about 60 ° with respect to the surface of the fuel 18 stored in the fuel groove 16 as shown in FIG. The injected vaporized air is configured to generate a swirling airflow swirling in the combustion chamber 12. The vaporized air injected from the fuel vaporizing nozzle 32 is supplied to the vertical portion 2 of the blower pipe 22 disposed in the combustion chamber 12.
3 is heated in the combustion chamber 12, which is at a high temperature, and the waste oil 18 is injected by injection of the heated vaporized air.
Is promoted, oxygen required for combustion of the fuel 18 is directly supplied to the surface of the waste oil 18, and the combustion of the waste oil 18 is promoted to increase the combustion temperature.

At this time, the combustion air is also uniformly introduced into the combustion chamber 12 from the multiple air discharge holes 28 formed in the vertical portion 23 of the blower tube 22, and the air discharged by the fuel vaporization nozzle 32 Combined with the supply of
Generates a combustion temperature of 00 ° C.

In the combustion chamber 12 where the waste oil 18 is burning at such a combustion temperature, the waste oil is generated when the waste is incinerated by the incinerator 50 or the like via the flue 14 connected to the bottom of the combustion chamber 12. When the smoke is introduced, soot contained in the smoke,
Dust, foul odors, hydrocarbons, carbon monoxide, etc. are burned and the smoke is colorless and odorless. In addition to nitrogen oxides, sulfur oxides and hydrogen chloride contained in the smoke, Toxic substances such as various dioxins that are decomposed for the first time are rendered harmless and released to the atmosphere via a chimney communicating with the combustion chamber.

[Experimental Example] The results of secondary incineration of smoke generated by incineration of discarded tires using the above-described secondary smoke incineration apparatus 10 of the present invention are shown below.

The experimental apparatus used here was a secondary incinerator 10 for smoke exhaust formed by a cylindrical wall made of iron having a diameter of 800 mm, a height of 1000 mm and a thickness of 12 mm.
A vertical section 23 having a length of 800 mm is formed by inserting a blower pipe 22 having a diameter of 80 mm into the combustion chamber 12 of the above. An air discharge hole 28 having a diameter 8 mm is formed in the vertical section 23 of the blower pipe 22.
A total of 56 holes are evenly drilled in the peripheral side surface of the blower tube 22.

A diameter 2 near the tip of the blower tube 22
Four 2 mm fuel vaporization nozzles 32 were radially protruded at an equal angle, and 15 m ³ / min of combustion air was introduced into the blower tube 22.

The waste oil 18 used as fuel is
Lubricating oil such as engine oil and transmission oil of automobiles collected at a gas station or the like, or a mixture of various other lubricating oils is used. This waste oil is used in the combustion chamber 12 at a rate of 0.1 liter / minute. The fuel was supplied to the fuel groove 16.

The incinerator 50 to which the secondary smoke incinerator 10 is attached is a known incinerator in which only compressed air is introduced into the incinerator without using auxiliary fuel or the like to incinerate waste. Then, a total of 100 kg of 15 discarded truck tires were put into a combustion chamber of a 380-liter incinerator and incinerated.

Table 1 shows the results of performance tests of the secondary smoke incinerator 10 of the present invention using the above experimental apparatus.

In Table 1 below, the "reference value" is a discharge reference value required for a waste incinerator, and is "treated".
Is a measured value of the concentration of various harmful substances measured by collecting and measuring the smoke exhausted from the chimney after being secondary incinerated by the secondary smoke incinerator 10 of the present invention.

[0044]

From the above results, according to the secondary smoke incineration apparatus of the present invention, it is possible to incinerate and remove harmful substances contained in the smoke exhaust, and to remove the harmful substances contained in the treated smoke exhaust. The amount of the substance was below any of the standard values required for waste incinerators.

[0046]

According to the configuration of the present invention described above, the harmful substances in the smoke exhaust are almost completely incinerated, and the smoke exhaust is colorless and odorless.
It can be discharged as harmless, especially 1500 to 160
By enabling high-temperature combustion of 0 ° C., it was possible to provide a method and an apparatus for secondary incineration of smoke exhaust gas, which can also decompose and detoxify dioxins that require a high temperature of 1400 ° C. or more for decomposition.

Further, when the smoke is subjected to secondary incineration,
A combustion temperature of 1600 ° C. can be achieved by using waste oil as fuel, the cost required for auxiliary fuel can be reduced, and the flue gas that can effectively utilize waste oil that has been conventionally incinerated as waste can be used as fuel. A secondary incineration method and apparatus could be provided.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an incinerator to which a secondary smoke incinerator according to the present invention is applied.

FIG. 2 is a cross-sectional perspective view of a main part of a secondary incineration device for flue gas of the present invention.

FIG. 3 is a sectional view taken along line IV-IV of FIG. 1;

FIG. 4 is a sectional view taken along line VV of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Secondary incinerator of flue gas 12 Combustion chamber 14 Flue 15 Projection part (of a flue) 16 Groove (fuel groove) 18 Waste oil (fuel) 20 Chimney 22 Blower pipe 23 Vertical part 24 Blower 26 Distributor plate 28 Air discharge port Reference Signs List 30 fuel pipe 32 fuel vaporization nozzle 33 tip of fuel vaporization nozzle 34 burner 36 fuel pump 38 fuel tank 50 incinerator

Claims (7)

[Claims] 1. A method for incineration of harmful substances contained in smoke by secondary incineration of smoke generated during incineration of waste, wherein the fuel supplied into a combustion space is ignited and the ignited fuel is ignited. The vaporized air is sprayed on the fuel to promote the vaporization and combustion of the fuel. Further, combustion air is introduced into the combustion space, and the fuel is burned at a combustion temperature of 1500 to 1600 ° C. in the combustion space. A method for incineration of the exhaust gas, wherein the harmful substances in the exhaust gas are incinerated by burning the fuel in the combustion space, and then the exhaust gas is discharged. 2. The fuel according to claim 1, wherein the fuel is heavy oil or waste oil.
The method for secondary incineration of flue gas as described. 3. The smoke exhaust according to claim 1, wherein the air blown to the ignited fuel is blown at an angle to a surface of the fuel to form an air flow swirling in a combustion space. Secondary incineration method. 4. The air blown to the fuel is heated in a combustion space before the air is blown to the fuel.
Or the secondary incineration method of flue gas described in 3. 5. An apparatus for introducing flue gas generated during incineration of waste into a combustion chamber formed therein and discharging the introduced flue gas after secondary incineration, wherein the apparatus is formed into a cylindrical shape. A combustion chamber formed by covering the upper and lower openings of the side wall with a wall, and a vertical portion disposed on a center line of the combustion chamber, wherein a number of air discharge holes are formed on a peripheral side surface of the vertical portion. A pipe, an air supply means connected to the blower pipe to supply combustion air into a combustion chamber, a fuel groove formed on a bottom wall surface in the combustion chamber, and storing fuel supplied from outside the combustion chamber, Fuel ignition means for igniting the fuel stored in the fuel groove; and a fuel vaporizing nozzle for discharging vaporized air toward the fuel stored in the fuel groove, and having one end communicating with the combustion chamber and the other end. For the introduction of flue gas communicating with an incinerator that incinerates waste Flue gas of the secondary incinerator, characterized in that it consists of a road. 6. The secondary exhaust gas incinerator according to claim 5, wherein the tip of the fuel vaporization nozzle is inclined in the circumferential direction of the combustion chamber. 7. The smoke elimination apparatus according to claim 5, wherein a base end of the fuel vaporization nozzle is connected to the blower tube.