JP2647813B2 - Downward ventilation type flame incineration method and incinerator using this method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a downdraft type flame which is capable of obtaining clean fuel gas by indirectly incinerating polymer waste by primary dry gasification and secondary combustion. The present invention relates to a dry distillation incineration method and an incinerator using the method.

[0002]

2. Description of the Related Art Generally, waste synthetic polymer wastes such as plastics, rubbers, and resins have a low moisture content and a high calorific value. There has been a problem that the gas and air generated on the surface are not satisfactorily mixed, and incomplete combustion is likely to occur.

[0003] In order to solve this problem, the direct incineration method not only requires high-speed combustion air injection but also requires an excess of about 2.5 times of air. reduces the thermal efficiency, pollutant occurred frequently, such as NO _X, also there is a problem that leads to such material damage by local overheating portion appears.

In recent years, the direct incineration method having such a problem has not been adopted as a method for treating waste synthetic polymer waste.
A dry distillation incineration method using a primary dry distillation gasification process using pyrolysis and a secondary complete combustion process is employed.

In this dry distillation incineration method, a partial combustion layer is formed with an air amount smaller than the theoretical air amount, and the heat is used to generate a flammable gas through a dry distillation gasification process through primary pyrolysis. This is an indirect incineration method in which a reactive gas is burned in a combustion chamber, and has the advantage that it can be incinerated with a lower excess air ratio than the direct incineration method described above. For example, the excess air ratio is about 2 to 2.5 in the direct incineration method, but about 1.5 to 2 in the indirect incineration method.

Accordingly, the dry distillation incineration method completely burns the generated dry distillation gas, so that the amount of pollutants generated is small and various types of combustion heat utilization methods can be selected and adopted.

[0007] Among such dry distillation incineration methods, FIG. 3 shows a conventional upward ventilation type dry distillation incineration method which is currently frequently used. In this dry distillation incineration method, polymer waste filled in the incinerator 1 is incinerated by a process of drying → pyrolysis → gasification → combustion. At this time, incinerator 1
The polymer waste introduced into the tank is converted into ash by the combustion of the lowermost layer and discharged downward, and air required for partial combustion is continuously supplied from the lower side to keep the combustion layer.

[0008] This will be described in more detail, to form a heat insulating portion of a suitable heat conditions by forming a partial combustion layer by supplying less insufficient air than the stoichiometric amount of air in the lower part of the polymer waste, CO ₂ to generate a combustion product gases and heat, such as H ₂ O (Zone D). This heat is used again as the heat of reaction for pyrolysis and gasification, and CO, N ₂ and trace amounts of C
Generate flammable gas such as H ₄ (charcoal gas) (Zon
e C).

[0009] In order to burn this combustible gas, it should be led to the combustion chamber through an upper outlet by dry distillation gasification.
That is, since the gas flows upward, it is an upward ventilation type.

[0010]

The above-described conventional upward ventilation type dry distillation incineration method has heretofore been used without a precise understanding of its generating mechanism. Problems were included. 1) By discharging the combustible gas upward, the generated combustible gas contains condensable tar and oil while passing through the waste layer, and in this process, heat is deprived and 200 ° C or less. As low-temperature gas. The condensable tar and oil components are condensed by the heat loss of the subsequent pipeline, adhere to the interior of the pipeline together with dust, accumulate, and eventually block the pipeline. In particular, blockage of the pipeline by tar causes serious impediments to flow. That is,
This makes it impossible to maintain the negative pressure required for the dry distillation gasifier, and exposes the gas to the outside and the danger of explosion. 2) Since condensable tar and oil have poor flammability, when they are burned in a combustion chamber, they cause an increase in the content of soot and pollutants in exhaust gas. 3) Excessive air flow into the dry distillation gasifier cannot be tolerated. The reason is that if air exceeding a certain limit is mixed in a state where the generated combustible gas is filled in the voids and the upper layer of the waste, there is a danger that the combustion gas explodes due to the heat of the combustion layer. . Until now, accidents in dry distillation incinerators were explosion accidents caused by excess air flowing in with little control of air volume.

[0011] Due to the various problems described above, the upward ventilation type dry distillation incineration method is difficult to operate and operate unless it is an expert, and it requires many devices for safety because it contains dangerous elements. . In fact, this type of incinerator is used to cause explosion accidents in the industry frequently, resulting in human injury.

SUMMARY OF THE INVENTION The present invention has been made to alleviate the above-mentioned problems at a glance, and includes a combustible gas produced by dry-distillation of a polymer waste during the gasification and combustion of a polymer waste. A downdraft type flame drier that removes condensable tar and oil, which can cause accidents such as deterioration of pipes, blockage of pipes, and explosions, thereby significantly improving the safety of the dry distillation incineration system and obtaining high-temperature clean fuel gas. An object of the present invention is to provide an incineration method and an incinerator using the method.

[0013]

According to a first aspect of the present invention, there is provided a method for performing indirect incineration by a primary dry gasification step and a secondary combustion step. The polymer waste is injected into the interior, and the volatile component of the polymer waste is burned while supplying about 25% of the theoretical air amount to the upper side of the distillation chamber. A flame layer is formed on the
The heat and combustion gas generated in the combustion step are guided downward to gasify in the lower carbon layer in the dry distillation chamber, and the combustible gas generated here is guided downward to mix with combustion air to form a combustion layer. It burns together with the residual carbon that has fallen.

An incinerator according to a second aspect of the present invention has a waste input port at an upper portion, and an air supply nozzle for supplying air for dry distillation is disposed, and polymer waste introduced from the waste input port. An upper-side drying chamber for dry-drying and gasification of the material, and a combustion air supply nozzle formed at a lower portion of the upper-side drying chamber, are disposed therein, and the combustible dry-gas generated in the upper-side drying chamber is led. A primary combustion chamber for mixing and burning the air supplied from the combustion air supply nozzle together with the residual carbon dropped through the roster, and a combustion air supply nozzle disposed on each side wall; The generated combustion gas is sequentially introduced in a stepwise manner to be subjected to a combustion treatment, whereby NO _x
Of the secondary combustion chamber and the tertiary combustion chamber for suppressing the generation of the gas.

[0015]

According to the first aspect of the present invention, air of about 25% of the theoretical air amount is supplied to the upper portion of the polymer waste layer charged into the still chamber to contain the polymer waste. The volatile components are burned, and the heat and combustion gas generated in this combustion process are guided downward to gasify in the carbon layer at the bottom of the dry chamber to produce flammable dry gas. Since it mixes with the air for combustion and burns with the residual carbon, the flow of the combustible dry gas generated as described above is passed not through the waste layer but through the downward high-temperature char layer and the ash layer. Since the condensable tar and oil contained in the volatile gas are thermally decomposed in the high-temperature layer, the combustible gas can be recovered as a clean fuel gas.

In the incinerator according to the second aspect of the present invention, the combustion gas generated in the primary combustion chamber is sequentially introduced into the secondary combustion chamber and the tertiary combustion chamber, and the combustion processing is repeated stepwise.
Prevents such produce incomplete combustion, the generation of the NO _X can increase the combustion efficiency and minimized.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A downward ventilation type flame dry distillation incineration method according to an embodiment of the present invention will be described below with reference to FIG. In FIG. 1, reference numeral 11 denotes a combustion chamber which forms a dry chamber into which a polymer waste is introduced from the outside. Above the polymer waste layer in the combustion chamber 11, insufficient air of about 25% of the theoretical air amount is provided. To form a flame layer while burning the easily combustible volatile components contained in the polymer waste layer. In this process, heat and NA ₂ of CO ₂ and H ₂ O are generated, and heat generated by the flame is generated. The solid state char which has been distilled off through the decomposition remains (Zo
ne A).

This carbon moves to the lower part, and the heat and the combustion gas are also guided downward, and the carbon and the combustion gas undergo an endothermic reaction, resulting in C
A combustible gas such as O ₂ , H ₂ and a trace amount of CH ₄ is generated (Zone B).

At this time, since the upper combustion heat is not lost to the char layer and the ash layer to be gasified except for the reaction heat used for the gasification, the heat is stored as it is and the high temperature of 800 ° C. is maintained.
The condensable tar and oil contained in the flammable gas in the dry layer are thermally decomposed (crac) while passing through the high temperature layer.
King) and becomes a clean fuel gas. This fuel gas can be used by separately collecting water.

Further, in order to fore-combust the residual carbon remaining after being used in the gasification reaction in the gasification layer (calculated about 25% of carbon remains), the residual carbon and ash must be 1%. By falling into the next combustion chamber and aging the flammable gas together, the residual carbon is completely burned, and the final residue is converted to ash with the lowest thermal loss and discharged to the outside.

Here, the characteristic feature is that a flame due to insufficient air is formed at the upper part of the polymer waste layer and the dry distillation is performed at the same time, the gas is guided downward, and a gasification reaction occurs in the char layer. Pass through the hot residual carbon and ash layers to produce clean hot combustible gases free of condensable tars and oils.

At this time, since the flame due to the volatile component of the polymer waste is always present in the upper part of the distillation chamber, there is no possibility that the flammable gas explodes even if the air is suddenly supplied, and the safety is high. Dangerous situations do not occur even if a specialist drives.

FIG. 2 is a schematic sectional view showing a downward ventilation type flame incinerator for realizing the flame incineration method of FIG. In FIG. 2, reference numeral 12 denotes a main body of the incinerator, 13 denotes a waste inlet provided at an upper portion of one side of the main body 12, 14
Is a drying chamber formed below the waste inlet 13 in the main body 12, 14a is a plurality of air supply nozzles for supplying drying air into the drying chamber 14, and 21 is a flame in the drying chamber 14. Is a primary auxiliary burner that injects and supplies the fuel.

Here, the primary auxiliary burner 21 and the air supply nozzle 14a supply a flame and dry air (insufficient air) to the upper portion of the polymer waste layer charged into the dry chamber 14. It is arranged. Therefore, in the dry distillation chamber 14, a flame downstream layer is formed on the upper side, and a gasification layer is formed on the lower side, thereby generating combustible gas.

In the lower part of the drying chamber 14, a rostul 15 is provided.
A primary combustion chamber 16 is defined by the air, and a flame is supplied from the secondary burner 22 into the primary combustion chamber 16 and combustion air is supplied from the combustion air supply nozzle 16a. ing.

A secondary combustion chamber 17 is connected to the primary combustion chamber 16 via a lower circulation port S1.
A plurality of combustion air supply nozzles 17a are arranged on the side wall, and have an ash outlet 20 at the bottom.

The secondary combustion chamber 17 has an upper circulation port S2.
The tertiary combustion chamber 18 is connected via the
A plurality of combustion air supply nozzles 18a are arranged on the side wall of the nozzle 8.

Here, the secondary combustion chamber 17 and the tertiary combustion chamber 18
, By stepwise combustion treatment sequentially introducing a combustion gas produced in the primary combustion chamber 17, the combustion gas is completely combusted, increasing the combustion efficiency and minimize the occurrence of the NO _X .

The exhaust gas burned in the tertiary combustion chamber 18 is heat-exchanged in the boiler 19 from the lower circulation port S3 of the tertiary combustion chamber 18 through the exhaust chamber, and then discharged by the induction blower 23. It has become.

Next, the operation will be described. The polymer waste introduced into the drying chamber 14 from the waste inlet 13 of the main body 12 is ignited by the primary auxiliary burner 21 on the upper side, and the polymer waste is supplied by the insufficient air supplied from the drying air supply nozzle 14a. The easily combustible volatile components contained in the polymer waste are burned and distilled.

As a result, a flame layer is formed in the upper portion of the inside of the drying chamber 14, and a combustible gas is generated while forming the gas layer in the flame drying layer and the lower portion by the flame drying and incineration method shown in FIG. Is done.

Next, the combustible dry gas generated in the gasification layer in the dry chamber 14 is guided downward and passes through the high-temperature residual carbon and ash layers, whereby the condensable tar and oil are thermally decomposed. After that, the mixture is mixed with the combustion air supplied from the combustion air supply nozzle 16 a in the primary combustion chamber 16 and ignited and burned by the flame from the secondary auxiliary burner 22.

At this time, the residual carbon remaining after being used for the gasification reaction falls along with the ash to the lower part through the roaster 15 and is converted into ash by continuing to burn in the primary combustion chamber 16. Exhausted from 20.

[0034] Here, the combustion gas produced in the primary combustion chamber 16, when an attempt is made entirely combusted in the primary combustion chamber 16, increases the occurrence of the NO _X due to the high temperature of the combustion heat,
Since overheating damage of the combustion chamber 16 is caused, to solve this,
The combustion gas is successively guided to the secondary combustion chamber 17 and the tertiary combustion chamber 18, and each of the combustion air supply nozzles 17 a, 1.
By the combustion air is supplied stepwise combustion process from 8a, generation of the NO _X is improved combustion efficiency are minimized.

Incidentally, the primary auxiliary burner 21 and the secondary auxiliary burner 22 are digested when the system reaches a normal state after ignition of the polymer waste, and even after the digestion, the polymer waste is spontaneously spontaneously. It continues to burn and is incinerated.

[0036]

As described above, according to the flame-distillation incineration method of the downward ventilation type and the incinerator using this method according to the present invention, the following effects can be obtained. 1) The condensable tar and oil contained in the generated combustible gas are reduced by 90% or more as compared with the conventional upward ventilation type dry distillation incineration method, and the gas temperature is high (about 800 ° C.). Since the gas is discharged, the gas is not clogged with the condensed tar oil even if the gas is used to be separately transferred through the line. 2) As described above, by removing condensable tars and oils having poor combustibility from the generated combustible gas,
The combustion efficiency is high, and the content of soot and pollutants in the combustion exhaust gas is reduced. For this reason, an exhaust gas treatment device can be dispensed with, the treatment load is significantly reduced, and the heat possessed by the combustible gas is increased, so that combustion is easily performed. 3) In terms of safety, according to the present invention, since a flame layer is always present due to the burning of volatile components in the upper part of the polymer waste, explosion of dry gas may occur even if air leaks. There is no. That is, when the amount of air increases, it is converted to the form of direct incineration by dry distillation, so that there is no danger element in safety. Therefore, continuous operation such as continuous introduction and ash extraction of polymer waste is easy, and even non-experts can easily operate. 4) In terms of the distillation speed, in the conventional upward distillation incineration method, the heat transfer of the thermal decomposition layer is almost entirely conducted by convection, so that the speed is low. On the other hand, in the present invention, the flame due to the insufficient air is directly used as the distillation heat. , Resulting in rapid dry distillation.

As described above, according to the present invention, by incinerating waste synthetic polymer waste by a down-flow ventilation dry-distillation method, a large amount of waste synthetic polymer waste can be treated and air pollutants can be reduced. There is an effect that generation can be suppressed to a minimum and safe incineration can be performed.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a downdraft type flame dry distillation incineration method according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a downward ventilation type flame incinerator for realizing the flame incineration method of FIG. 1;

FIG. 3 is a conceptual diagram showing a conventional upward ventilation type dry distillation incineration method.

[Explanation of symbols]

 13 Waste input port 14 Drying chamber 14a Drying air supply nozzle 15 Rostor 16 Primary combustion chamber 17 Secondary combustion chamber 18 Tertiary combustion chamber 16a, 17a, 18a Combustion air supply nozzle

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location F23G 5/16 ZAB F23G 5/16 ZABE

Claims (2)

(57) [Claims] 1. A dry distillation incineration method for indirectly incinerating polymer waste according to a primary dry distillation gasification step and a secondary combustion step. By burning the volatile components of the polymer waste while supplying about 25% of the theoretical air amount to the upper side of the room, a flame layer is formed on the upper portion of the polymer waste and the flame is dried. Guiding the heat and combustion gas generated in the combustion step downward to gasify in a lower carbon layer in the dry distillation chamber,
A downdraft flame dry distillation incineration method characterized in that the combustible gas generated here is guided downward and mixed with combustion air to form a combustion layer and combust with residual carbon dropped. 2. An upper-side dry chamber having a waste input port at an upper portion, and a dry air supply nozzle disposed therein, for performing dry storage and gasification of polymer waste input from the waste input port. And a combustion air supply nozzle formed at a lower portion of the upper-side drying chamber, and a flammable drying gas generated in the upper-side drying chamber is guided to the combustion air supply nozzle together with the residual carbon dropped through the roaster. A primary combustion chamber that mixes and burns with air supplied from a nozzle, and a combustion air supply nozzle is disposed on each side wall, and the combustion gas generated in the primary combustion chamber is sequentially introduced to gradually increase the combustion gas. combustion process, and downward ventilated flame dry distillation incinerator, characterized in that consisted to suppress the generation of NO _X 2 primary combustion chamber and the tertiary combustion chamber.