JP2516699B2 - Waste incineration method and incinerator - Google Patents

Description

TECHNICAL FIELD The present invention relates to an incineration method and an incinerator,
In particular, the present invention relates to a method for incinerating industrial waste, which is generally difficult to burn except metals, and an incinerator therefor.

2. Description of the Related Art Conventionally, in general, general industrial waste is treated by removing metal and incinerating combustibles in an incinerator. As an incinerator for this purpose, a furnace equipped with a grate is generally used and burned under the supply of fuel, but the waste contains, for example, plastic or the like. Occasionally, the combustion takes place at a high temperature, which often damages the grate and the furnace wall, and this repair requires not only the operation of the incinerator but also a large repair cost. However, there is a problem that the service life of the incinerator is remarkably shortened.
In addition, when incinerating plastic, etc., soot, sulfur oxides, nitrogen oxides, and harmful gases such as hydrogen chloride are remarkably generated, and incidental equipment is required to prevent them from scattering. Prevention cannot always be done to a satisfactory degree, so smoke, sulfur oxides,
The current situation is that harmful gases such as nitrogen oxides and hydrogen chloride diffuse from the chimney into the atmosphere, causing serious pollution problems.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Therefore, the present invention is capable of solving the above-mentioned problems in combustion of various kinds of waste, which are generally considered to be difficult to burn. It is an object of the present invention to provide an improved combustion method and incinerator.

Means for Solving the Problems In order to solve this problem, the present invention comprises a step of charging incineration waste into a combustion chamber, and igniting the upper surface of the incineration waste, The primary combustion air from above and compulsorily supplying stratified secondary air adjusted from the side of the upper surface layer for combustion, and the combustion gas generated by this combustion is secondary. While discharging from the chimney through the combustion chamber, the heat from this combustion is transferred to the lower layer, and the transferred heat causes unburned gas to be generated in the lower layer of the upper surface layer and the lower layer to be dried. A combustion process in which unburned gas generated in the lower layer is combusted by supplying primary air from above and forcibly supplying layered secondary air whose air amount is adjusted from the side portion corresponding to this lower layer, Install the combustion process The present invention provides a method for incinerating waste to be incinerated, which comprises a step of sequentially repeating the steps until reaching the bottom layer of the incinerated waste that has been entered, and finally, a step of discharging ash generated by combustion from the combustion chamber.

Also, as an incinerator suitable for carrying out this incineration method, a substantially vertical main combustion chamber having an appropriate plane contour and a certain height and an open upper part, and the main combustion chamber being opened A cover for closing the upper part, a substantially horizontal secondary combustion chamber connected to the upper part of the main combustion chamber, a substantially vertical chimney connected to the secondary combustion chamber, and an opening in the main combustion chamber , A number of rows of secondary air ports arranged horizontally at vertical intervals, and means for forcibly supplying individually regulated air amounts to the secondary air ports of each row, said main An incinerator for waste is provided, which comprises a primary air port opening at the top of a combustion chamber.

It is preferable that the cover has a primary air port, and it is preferable that the secondary combustion chamber has a preliminary burner port and an air supply port. Furthermore, in this incinerator, the main combustion chamber can be embedded in the ground, the furnace bottom can be left open, and only the side wall can be covered with the refractory material.

The incineration method of the present invention is carried out as described above, and the incinerator according to the present invention is characterized by having the above-mentioned configuration, but the present invention has the greatest feature. When burning incinerated waste, it is not necessary to supply special fuel except for the first ignition point, and the incinerated waste itself is heated to a high temperature. Combustion is maintained by the combustion heat generated.

Example Hereinafter, a detailed description will be given with reference to the accompanying drawings showing an incinerator according to an example of the present invention.

First, the figure is a schematic view showing the incinerator 30 according to an embodiment of the present invention in a longitudinal section.As shown in the figure, the incinerator 30 has a substantially rectangular plane contour and a certain depth. With a substantially vertical main combustion chamber 1 and a substantially horizontal secondary combustion chamber (smoke with a rectangular cross section connected to the upper part of one of its side walls). Side wall, which is mainly composed of a chimney 2) and a chimney 3 having a certain height, which is connected to an end of the chimney 2) and in which a secondary combustion chamber (flue) 2 of the main combustion chamber 1 is provided. In the lower part of the side wall part opposite the part,
An ashing pit 4 having a rectangular plane contour and a certain depth is connected.

And, these main combustion chamber 1, secondary combustion chamber (flue) 2
As a general rule, the ashing pit 4 is an underground type in which the whole is buried in the ground or a semi-underground type in which a part thereof is buried. Further, the peripheral wall and the bottom 3 ₀ of the lower portion of the side walls 1 ₀ and chimney 3 in the main combustion chamber 1 is made of concrete, furthermore, the side walls 1 ₀ and made these concrete
3 ₀ of the inner surface and the secondary combustion chamber (the flue) 2 of the peripheral wall is for forming a refractory heat-resistant material. That is, the main combustion chamber 1 refractory heat sidewall 1 _1, the secondary combustion chamber (the flue) refractory heat shell 2 ₁ to 2 and the refractory heat peripheral wall in the lower portion of the chimney 3,
3 ₁ are formed respectively. Incidentally, ash removal pit 4 is formed by a peripheral wall 4 ₀ made concrete. In addition, the bottom of the main combustion chamber 1 is not exposed to concrete or refractory heat-resistant material, and is an open field with the excavated surface exposed.

In the upper opening of the main combustion chamber 1, a flat horizontal box-shaped cover 5 having a plane contour and dimensions so as to cover the entire opening area is horizontally movably installed. 5 has several primary air openings 6 that pass through it vertically.
Is open. In this embodiment, a water cooling wall 7 having a rectangular cross section is installed around the upper opening of the main combustion chamber 1 so as to surround the opening. It is mounted on the upper surface of the water cooling wall 7 so as to be horizontally movable.

Further, the refractory heat sidewall 1 ₁ of the primary combustion chamber 1 is vertically spaced horizontal secondary air inlet 8 _{1-8 3} sequences are provided, these secondary air ports 8 ₁ ~ 8 ₃ each,
Forced ventilation is performed from the blower 10 installed on the ground via the pipelines 9 _{1 to} 9 ₃ . And each pipeline
Valves 11 _{1 to} 11 ₃ are installed in 9 _{1 to} 9 ₃ respectively, and the amount of air supplied to each of the pipe lines 9 _{1 to} 9 ₃ can be controlled separately.

Additionally, the secondary combustion chamber in the fire heat sidewall 2 ₁ (flue) 2, substantially intermediate portion of its length, the secondary combustion chamber (flue)
A secondary air supply port 13 is opened in the secondary combustion chamber (flue) 2 above the at least one spare burner 12 which is open in the inside of the secondary burner 12.

 Next, a method of operating this incinerator 30 will be described.

First, the cover 5 that closes the upper opening of the main combustion chamber 1 of the furnace 30 in the state as shown in the figure is opened by horizontally moving it, and is incinerated from the opening into the main combustion chamber 1. The combustible waste to be charged is charged until the height of the bottom of the opening of the flue 2 is reached.

In this state, the upper opening of the main combustion chamber 1 is closed to the state shown in the figure by returning the cover 5 to the original position.

Then, a combustible material (for example, a piece of cloth soaked with oil) is placed on the upper surface of the incineration waste layer charged in the main combustion chamber 1, and the combustible material is ignited and burned by an appropriate means. Thus, the initial combustion of the incineration waste in the uppermost layer is started.
In this initial combustion, the primary air is supplied from the primary air port 6 opened in the cover 5, and the valve is blown from the blower 10.
11 ₃ and the conduit 9 ₃ through the secondary air port 8 _{3 on} the side of the top row.
Turbulent air flow is generated in the main combustion chamber 1 by supplying stratified secondary air with a controlled amount from
As a result, unburned gas is generated in the incineration waste in the uppermost layer due to the water gasification reaction, and the incineration waste in this layer is burned without special fuel supply by combustion of the unburned gas. Is. In this initial combustion, the valves 11 ₂ and 11 ₁ remain closed and the secondary air port 8 ₂ and
Air is not supplied from 8 ₁ . Therefore, the incineration waste is burned only by the heat generated by the combustion of itself, the primary air supplied from above and the secondary air supplied from the side. Since air is not supplied from below in this combustion, the amount of low-temperature unburned gas supplied from below is small and the combustion reaches a relatively high temperature. Therefore, the combustion gas containing sulfur oxides, nitrogen oxides, hydrogen chloride, etc. generated in this initial combustion is discharged to the atmosphere through the secondary combustion chamber (flue) 2 and the chimney 3. However, since the combustion takes place at a relatively high temperature, the generation of smoke, sulfur oxides, nitrogen oxides, and hydrogen chloride during the combustion period is minimized except during the first ignition. At the same time, the generation of odorous harmful gases can be suppressed to a low value, for example, 1/10 or less of the emission standard specified by each public institution.

Since there is no air supply from below, the heat generated during this combustion is transferred from the incineration waste in the uppermost layer to the incineration waste in the lower layer directly below it in a good and even manner. After the incineration waste is brought to a high temperature and dried, unburned gas is generated in this lower layer. At the same time, the heat is also transferred to the incineration waste layer below that to dry it. As described above, primary air is supplied from the upper primary air port 6 to the incineration waste layer in which unburned gas is generated in the lower layer of the incineration waste in the uppermost layer, and the side portion corresponding to this lower layer is supplied. from the middle column of the secondary air ports _82, by forcibly supplying secondary air to adjust its amount to be combusted waste burning unburned gas, complete combustion of the combustion waste that layer It can be done. Of course, in this case,
The amount of the secondary air is adjusted supplied from the middle row of secondary air ports ₈₂ are adjusted by the control valve 11 ₂ is required and optimal for complete combustion. In addition, at the time of this combustion,
Secondary air from the uppermost secondary air port 8 ₃ is limited to a small amount by controlling the valve 11 ₃ . In this way, the lower incineration waste layer in which the unburned gas is generated completely burns as the uppermost incineration waste layer. The exhaust gas generated in this combustion process is discharged as smokeless and odorless exhaust gas into the atmosphere through the secondary combustion chamber (flue) 2 and the chimney 3. Further, due to this combustion, the lower layer of the incinerated waste that is located below the incinerated waste layer is dried by the transfer of the heat generated by the combustion, and the incinerated waste layer below that is also dried. Let Unburned gas lower in this downward, the secondary air inlet 8 ₁ of the bottom row in correspondence, the secondary air having an adjusted amount of air combusted is supplied from the side, complete combustion of the incineration combustion product To do.

In this way, the combustion process is sequentially and continuously performed from the upper incineration waste layer to the lower incineration waste layer, and finally, the bottommost incineration waste layer is formed. It is what causes complete combustion.

In other words, in the combustion process, the process of drying, the generation of unburned gas, and combustion is sequentially repeated from the incineration waste in the upper layer to the incineration waste in the lower layer, and the final incineration is completed. The entire amount of waste is burned, and powdered ash, which is burning dust, remains on the bottom of the furnace.

Since the hearth of the main combustion chamber 1 is a natural open field without being subjected to concrete, the humidity generated from this hearth causes the temperature of the incinerated waste in the main combustion chamber 1 to be unreasonable. This prevents the temperature from becoming extremely high and maintains the temperature in the main combustion chamber 1 at an optimum temperature, for example, about 1,200 ° C., which is useful for complete combustion.

Also, in this case, if necessary, the fresh burner 12 ignited the spare burner 12 installed in the secondary combustion chamber (flue) 2 and simultaneously sent through the unburned gas and the air supply port 13. The secondary air can be mixed with the secondary air to completely burn it.

In this way, when the entire amount of the incineration waste put into the main combustion chamber 1 is incinerated, the combustion residues are taken out from the ash extraction pit 4 to the ground.

As a result, one cycle of incineration of the incineration waste is completed, and thus the incineration waste can be newly incinerated by repeating the above process for the new incineration waste.

In addition, in this incineration process, if necessary,
For example, by installing and placing a cyclone dust collector on the bottom of the chimney 3, it is possible to effectively prevent the scattering of soot and the like.

In addition, when the waste contains a large amount of plastic materials such as vinyl chloride, by supplying lime powder to this waste during combustion, chlorine gas, sulfur dioxide, etc. Can be neutralized,
In this case, a small amount of hardened ash and neutralized lime powder are accumulated as combustion residues. However, this hardened ash can also be easily taken out from the ash extraction pit 4.

The water-cooling wall 7 can circulate water inside the water-cooling wall 7 to obtain hot water by utilizing the heat generated by the combustion of waste to be incinerated. Since it also has a function of protecting the peripheral wall and the side wall from heat, it is preferably installed as much as possible.

Thus, according to the present invention, the combustion of the incineration waste in the main combustion chamber 1 is performed stepwise from the uppermost layer to the lower layer, and in the combustion process, the wastes to be incinerated are sequentially extracted. Combustion by heating to high temperature, drying, producing unburned gas, adjusting and supplying primary and secondary air optimal for combustion, the substantially complete combustion of which is special It can be done without the need to supply fuel.

 Next, an experimental example of the present invention will be described.

Experimental example 1 1. Waste to be incinerated Dust waste from urban households 2. Volume and weight (pressed) Volume: 700 × 700 × 700 mm Weight: Approx. 700 kg 3. Combustion process It was observed that no smoke was generated after that.

4. Temperature in the main combustion incinerator Upper layer temperature 800 ℃ ~ 1,400 ℃ Middle layer temperature 600 ℃ ~ 900 ℃ Lower layer temperature 100 ℃ ~ 400 ℃ Average temperature Approximately 1,200 ℃ 5. Amount of ash after combustion Approximately 1.2 kg 6. Results The incineration result was judged to be good.

Experimental Example 2 1. Waste to be incinerated Industrial waste (plastic materials such as vinyl chloride) 2. Measured concentration of exhaust gas Dust concentration 0.018g / Nm ³ (0.50g / Nm ³ ) Sulfur oxide 0.076Nm ^{3 /} h (0.86 Nm ³ / h) Nitrogen oxides 56.8ppm (250ppm) Note: The value in parentheses is "emission standard", and if it is less than this value, it is judged as "appropriate".

3. Result The concentration of exhaust gas is below the emission standard, so it complies with this standard.

From the above experimental results, it will be understood that the present invention has achieved the object.

EFFECTS OF THE INVENTION According to the present invention, by compulsorily supplying the layered secondary air whose amount of air is adjusted from the corresponding side portions, combustion of the incineration waste is sequentially performed from the upper surface layer to the lower layer,
It is possible to minimize the soot and smoke by complete combustion without lowering the combustion area to a low temperature due to the low temperature unburned gas that accompanies the air supply from below, and it is necessary to supply fuel except during ignition. There is no generation of sulfur oxides and nitrogen oxides due to fuel. Depending on the waste to be incinerated, the generation of harmful gas such as hydrogen chloride can be minimized by supplying lime powder to the main combustion chamber during combustion.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing one embodiment of an incinerator for carrying out the method of the present invention. 1 ... Main combustion chamber, 2 ... Secondary combustion chamber (flue), 3 ... Chimney, 4 ... Ash pit, 5 ... Cover, 6 ... Primary air port, 7 ... Water cooling wall, 8 …… Secondary air port, 10 …… Blower, 11 …… Valve, 12 …… Spare burner, 13 …… Secondary air supply port.

Claims (5)

(57) [Claims] 1. A process of charging incineration waste into a combustion chamber, igniting an upper surface layer of the incineration waste, supplying primary air to the upper surface layer from above, and the side of the upper surface layer. The initial combustion step of combusting by forcibly supplying the stratified secondary air whose amount of air is adjusted from the section, and the combustion gas generated by this combustion is discharged from the chimney through the secondary combustion chamber, while this combustion The heat generated in the lower layer is transferred to the lower layer, the unheated gas is generated in the lower layer of the upper surface layer, and the lower layer is dried. And a combusting process for combusting waste to be incinerated by forcibly supplying stratified secondary air with an adjusted amount of air from the corresponding side parts, and this combustion process is charged. The lowest layer of incinerated waste Sequentially repeating steps and, finally, incineration method of the combustible waste, characterized in that comprising a step of discharging ash generated by combustion from the combustion chamber to be. 2. A substantially vertical main combustion chamber having an appropriate plane contour and a height and an open upper portion, a cover closing the open upper portion of the main combustion chamber, and the main combustion chamber. A substantially horizontal secondary combustion chamber connected to the upper part of the chamber, a substantially vertical chimney connected to the secondary combustion chamber, and a vertically-arranged horizontal arrangement that opens into the main combustion chamber. A plurality of secondary air openings, and means for forcibly supplying individually regulated air amounts to the secondary air openings of each row,
An incinerator for waste, comprising a primary air port opening at an upper part of the main combustion chamber. 3. The waste incinerator according to claim 2, wherein a primary air port is provided in the cover. 4. The waste incinerator according to claim 2, wherein a secondary burner port and an air supply port are provided in the secondary combustion chamber. 5. The incinerator for waste according to claim 2, wherein the main combustion chamber is embedded in the ground, the bottom of the furnace is left open, and only the side wall is covered with a refractory material.