JP2002130627A - Thermal decomposition processing equipment and operation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the difficulties of prior art that when a substance to be processed containing combustible components is heated for dry distillation, decomposition gas containing combustible components such as a tar fraction is produced, and hence on a gas conduit for guiding the produced decomposition gas to the next process (the decomposition gas is combusted in a combustion furnace) various components contained in the decomposition gas and soot are sometimes deposited, and particularly when the heating operation is interrupted and hence no decomposition gas is produced, there is no medium (gas) to be sucked existent in a thermal decomposition furnace and in the gas conduit, but there is existent therein sublimed substances and fine solid substances, which adhere to an internal wall surface of the gas conduit and is solidified to close the gas conduit and to cause local combustion. SOLUTION: A decomposition gas conduit is heated and is heat-insulated at the temperature of produced decomposition gas on above in a heat insulation pipe into which waste gas of a decomposition gas combustion furnace is introduced. When the heating of the thermal decomposition furnace is interrupted, the decomposition gas combustion furnace is interrupted after a predetermined time after the interruption of the heating of the thermal decomposition furnace.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pyrolysis facility for indirectly heating and pyrolyzing an object to be treated, such as waste, to reduce its volume (by drying, carbonizing, ashing, etc.) and a method of operating the same. In particular, when the cracked gas conduit for guiding the cracked gas generated in the cracking furnace to the cracked gas combustion furnace is kept warm by the cracked gas, supply of the cracked gas is performed by the cracking furnace or cracked gas. The present invention relates to a technique for suppressing the generation of deposits and the solidification of deposits in a cracked gas conduit by stopping supply after a certain period of time after stopping heating of a combustion furnace.

[0002]

2. Description of the Related Art Various objects to be treated containing combustible components (eg, wastes, various kinds of dried products, incinerated materials, etc.) are subjected to heat treatment by various methods. For example, it is common practice to put an object to be treated into a heating vessel, pyrolyze it by dry distillation (steaming) by heating from the outside, separate it into cracked gas and carbide, obtain a carbide, and use this as a resource. ing.

[0003] In this case, the amount of combustible components contained in the treated material varies in size, but various types of waste (general waste, industrial waste, etc.), sludge, incinerated ash, fly ash, contaminated soil, There are various types of construction waste, various types of shredder dust, metal scrap, and organic substances.

[0004] An object to be processed is put into a rotary kiln,
There is also known an apparatus in which an object to be processed in a rotary kiln is processed under a predetermined temperature condition by indirect heating (for example, Japanese Patent Application Laid-Open No. 6-2)
69760).

On the other hand, the present inventors have proposed that the organic chlorine compound (hydrogen chloride), which is an organic substance (halogen such as chlorine), performs "suppression of emission" instead of the conventional "suppression of emission". It has been proposed to suppress the generation of harmful substances such as hydrogen chloride, make the exhaust gas harmless, make the residue harmless, and reduce the damage to the treatment equipment due to chlorine. (See, for example,
155326, JP-A-10-43713, JP-A-10-235186, JP-A-10-235187, etc.).

In the case where the object to be treated is not subjected to the burning treatment but to the dry distillation treatment, the heating treatment generates a decomposition gas containing a combustible component such as a tar component, and the treatment is also required. .

That is, in a thermal decomposition treatment facility in which an object to be treated such as waste is subjected to indirect heating treatment to reduce the volume (drying, carbonization, incineration, etc.), sublimation substances in the decomposition gas generated by decomposition are generated. There is a risk that solidification will occur as needle-like crystals upon cooling, and unburned tar, ash, and fine solids will adhere to the inner walls of the gas conduit and solidify, causing problems such as blockage of the gas conduit and local combustion. is there.

Conventionally, in order to solve these problems, a cleaning device is provided in a gas conduit to remove dust adhering and accumulating (JP-A-2000-136387), or to keep a gas conduit at a predetermined temperature. It has been proposed to prevent the adherence by performing the process (JP-A-10-205726).

[0009]

The provision of a cleaning device in the above-described gas conduit and removal by mechanical means can be expected to remove deposits, but it becomes an obstacle to the flow path, and the resistance of the gas flow path is reduced. In addition, it will adhere to the means itself.

In the method of keeping the gas pipe at a predetermined temperature, the effect of preventing adhesion can be expected by keeping the temperature, but the problem is that the gas may adhere and solidify in the cooling process when the operation is stopped, and the problem remains in this respect. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to prevent adhesion and solidification in a cooling process when operation is stopped.

[0012]

In order to solve the above-mentioned problems, various studies have been carried out. In order to solve the above-mentioned problems, a hot gas supplied to a heat retaining pipe for keeping a decomposition gas conduit heated is supplied to the heating furnace by (a) stopping heating of a pyrolysis treatment furnace. (B) The cracked gas combustion furnace is continuously operated for a fixed time after the heating of the pyrolysis furnace is stopped. It is preferable that the supply be continued for a certain period of time after the stoppage. (C) When sublimates and fine solids adhere to the decomposition gas conduit by operating as described above,
It has been found that such growth and solidification (easy to solidify in the cooling process) can be prevented.

[0013] Furthermore, the hot gas for heat retention introduced (supplied) to the heat retention pipe is obtained by branching and using a part of high-temperature exhaust gas discharged from a decomposition gas combustion furnace (about 850 ° C). We paid attention to effective use.

The present invention has been made based on these findings, and a thermal decomposition treatment facility for solving the above-mentioned problems is provided with a conveying means for conveying an object to be processed, and an external indirect heating of the object to be processed. Pyrolysis treatment means for reducing the volume, residue treatment means for collecting generated residues, cracked gas burning means for burning the generated cracked gas, and introducing the cracked gas generated by the pyrolysis treatment means to the cracked gas burning means Cracking gas conduit means;
Exhaust blower means for exhausting the exhaust gas burned by the cracked gas combustion means, wherein the cracked gas conduit means comprises a heat retaining pipe surrounding the cracked gas conduit, and the temperature of the cracked gas generated by the thermal decomposition processing means in the heat retaining pipe. It is configured to introduce the above hot gas.

As the hot gas introduced into the above-mentioned heat retaining pipe, it is preferable to introduce the hot gas obtained by the decomposition gas combustion means from the viewpoint of effective use of the exhaust gas.

[0016] The operation method of the thermal decomposition treatment facility includes a conveying means for transporting the object, a thermal decomposition means for reducing the volume of the object by external indirect heating, and a residue treatment for recovering generated residues. Means, cracked gas burning means for burning the generated cracked gas, cracked gas conduit means for guiding the cracked gas generated by the pyrolysis processing means to the cracked gas burning means, and exhaust gas for discharging the exhaust gas burned by the cracked gas burning means. Blower means, and the decomposition gas conduit means comprises a decomposition gas conduit and a heat retaining pipe surrounding the decomposition gas conduit, and introduces a hot gas having a temperature equal to or higher than the temperature of the decomposition gas generated by the thermal decomposition treatment means into the heat retaining pipe. In the operation of keeping the temperature and stopping, the introduction of the heat-retaining hot gas is performed continuously for a certain period of time after the stop of the heating of the thermal decomposition treatment means.

Further, as another embodiment, a conveying means for conveying the object to be processed, a thermal decomposition processing means for reducing the volume of the object by external indirect heating, and a residue processing means for collecting generated residues A cracked gas combustion means for burning the cracked gas generated, a gas conduit means for guiding the cracked gas generated by the pyrolysis treatment means to the cracked gas combustion means, and an exhaust blower means for exhausting the flue gas burned by the cracked gas combustion means. The gas conduit means comprises a cracked gas conduit and a heat retaining tube surrounding the cracked gas conduit, and heat is introduced into the heat retaining tube by introducing a hot gas having a temperature equal to or higher than the temperature of the cracked gas generated by the thermal decomposition treatment means. In the stopping operation, the introduction of the hot gas for keeping the temperature is stopped after the heating of the thermal decomposition processing unit is stopped, and then the combustion of the decomposition gas burning unit is stopped, and thereafter, is continuously performed for a certain period of time.

As the hot gas introduced into the heat retaining pipe, it is desirable to use an exhaust gas obtained by a decomposition gas combustion means.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual diagram of a thermal decomposition treatment facility according to the present invention. In the figure, reference numeral 1 denotes a crushing means for crushing the object,
Reference numeral 2 denotes a metal removing means for removing iron-based metals such as nails from the crushed workpiece, and includes, for example, a magnetic separator.

Reference numeral 3 denotes a container for storing the removed metal, and reference numeral 4 denotes a first closed conveying means, which is also called a pipe conveyor. As shown in FIG. And flexible transfer means 6 provided in the endless conduit 5 and circulating in the endless conduit 5.

The endless pipeline 5 includes a lower horizontal space 5a forming an outgoing pipeline G, a standing (vertical or inclined) space 5b, an upper horizontal space 5c, and an upper horizontal space 5d forming a return pipeline R. , An upright pipe section 5e and a lower horizontal pipe section 5f, and the forward pipe G and the return pipe R are connected endlessly by curved pipes 5g and 5h.

As shown in FIG. 2, the flexible conveying means 6
Provided as an endless flexible conveying means in the endless conduit 5,
An object receiving body (hereinafter, referred to as a blade) 6a, a flexible indexing body (hereinafter, abbreviated as a chain) 6b such as a multi-joint, a chain or a rope, and the chain 6b
, And the index body is circulated in one direction. The drive source 7 includes a motor 7a,
It is composed of a sprocket 7b which is driven by engaging with the index body,
The sprocket 7b is connected to the flexible conveying means 6 in the curved tube 5h.
And drives the flexible conveying means 6. This meshing portion is sealed with a cover 7c.

Reference numeral 8 denotes an inlet for an object to be processed provided in the lower horizontal pipe portion 5a of the outward pipe, and 9 denotes an upper horizontal pipe section 5d of the return pipe R.
2 shows a discharge port for the object to be processed provided in the apparatus.

Reference numeral 10 denotes a hopper which stores the object to be processed from the first closed conveying means 4 and supplies it to the first fixed amount supplying means 12 via the second closed conveying means 11. The configuration of the second closed transport means 11 is the same as that of the first closed transport means 4.
A treatment agent 14 as a dechlorinating agent is injected into an appropriate portion of the second closed conveying means 11, for example, into the lower horizontal pipe portion 5a. The connection between the supply ports and the discharge ports of the closed transport means 4 and 11 (the metal removing means 2, the hopper 10, and the fixed quantity supply means 12) is a hermetic connection.

The fixed-quantity supply means 12 also has open / close valves on the upper and lower sides, and is operated so that both open / close valves are not opened at the same time, thereby preventing the flow of outside air.

Reference numeral 15 denotes a pyrolysis furnace (hereinafter, abbreviated as a desalination furnace) for drying and dechlorinating the article to be treated. And heat
A degassing treatment is performed by reacting a decomposition agent which decomposes and precipitates from an object to be treated by heating with a treating agent. For example, in the case of a rotary kiln type, a gas duct 1 is provided on the outer periphery of a rotary cylindrical body 15a.
5b is formed and a hot gas is introduced to heat the object to be processed in the rotating cylindrical body 15a. Although not shown, the rotary cylinder 15a is rotatably supported by a support roller, is rotationally driven by rotary drive means, has a feed blade inside, and is rotated by the rotation of the rotary cylinder 15a. The object is transferred from the supply port side to the discharge port side while stirring.

Reference numeral 16 denotes a supply side duct,
The mixture of the object to be treated and the treatment agent quantified by the above is supplied into the rotating cylindrical body 15a. Reference numeral 17 denotes an induction heating means having a heating coil, which is provided on the outer periphery of the rotating cylinder 15a at both ends of the gas duct 15b in a non-contact manner with the rotating cylinder 15a. The lowering of the temperature at both ends is supplementarily heated.

Reference numeral 18 denotes a pyrolysis furnace (hereinafter, referred to as a carbonization furnace) for carbonizing an object to be processed which has been dechlorinated in the desalination furnace 15.
Thus, the desalting furnace 15 has the same configuration as the pyrolysis furnace. That is, the rotating cylinder 18a and the rotating cylinder 18
a of a gas duct 18b as an external heating means provided on the outer periphery of a. Reference numeral 19 denotes induction heating means provided on the outer periphery of the rotary cylindrical body 18a on both sides of the gas duct 18b.

Numeral 20 denotes a lead-in / out duct for the object to be treated, which introduces the object to be treated heated in the desalination furnace 15 into the carbonization furnace 18.
Reference numeral 21 denotes a discharge-side duct, which introduces the carbide that has been carbonized in the carbonization furnace 18 into the quantitative supply unit 22.

Incidentally, a mechanical seal C is applied to each rotating contact portion between the rotating cylindrical bodies 15a and 18a and the gas ducts 15b and 18b to prevent leakage of hot gas. Similarly, a mechanical seal C is also applied to a rotating contact portion between the rotating cylindrical body 15a and the supply-side duct 16 and the lead-in / duct duct 20, and a rotating contact portion between the rotating cylindrical body 18a and the lead-in / out duct 20 and the discharge-side duct 21. Gas leakage from the rotating cylinder is prevented.

Reference numeral 23 denotes a hot blast stove, which burns a fuel such as LNG, LPG or petroleum with a burner or the like to generate a hot gas, supplies the hot gas into a gas duct 18b of the coking furnace 18, heats the coking furnace 18, and connects After being introduced into the gas duct 15b of the desalination furnace 15 through the pipe 24 and heating the desalination furnace 15, the gas pipe L
₁ to the heat exchanger 26, and a part of the heat exchanger
To be introduced. Reference numeral 27 denotes a circulation blower for circulating the hot gas.

Numeral 28 denotes a third closed conveying means having the same configuration as the first closed conveying means 4, which decomposes the carbide quantified by the second quantitative supplying means 22 through the third quantitative supplying means 29. It is introduced into the gas combustion furnace 30. This cracked gas combustion furnace 3
No. 0 is a gas obtained by burning a fuel such as LNG, LPG or petroleum and carbonizing, as well as cracking gas (carbonization gas) generated during the heat treatment in the desalination furnace 15 and the carbonization furnace 18 in addition to the cracking gas conduit L _2. , burning is introduced through the L _3. After the exhaust gas after combustion was dust collection in a cyclone 31 via a gas pipe L _4, the heat is recovered and introduced into heat exchanger 26, and cleaned in a bag filter 32 is discharged through the silencer 33.
An exhaust blower 34 sucks and discharges these gases.

The heat exchanger 26 is divided into two gas chambers, one a hot gas after heating the hot gas and the respective heat treatment furnace as it is discharged introduced through the gas pipe L ₁ from the hot air oven 23 The combustion gas generated from the cracked gas combustion furnace 30 is
Since various substances are mixed in, the gas is cleaned by the bag filter 32 through the other gas chamber and then discharged.

Numeral 35 is a hot water utilization facility, which circulates water in the heat exchanger 26 by a pump 36 to obtain hot water.

The connection of each device forming the passage of the object to be processed from the metal removing means 2 to the cracked gas combustion furnace 30 is a hermetic connection, and the entire passage is kept airtight and maintains a low oxygen region. At the same time, the odor is formed so as not to leak outside.

When the material to be treated does not necessarily need to be carbonized, a fixed-quantity supply means (not shown) is provided from the lead-in / out duct 20.
May be connected to the third closed transport means 28 via the.

Reference numeral 37 denotes an incineration recovery means which opens the door a when the amount of ash generated by burning in the cracked gas combustion furnace 30 reaches a predetermined amount, and removes the ash.

The cracked gas conduits L ₂ and L ₃ are each constituted by a double pipe. That is, as shown in Figure 1 of the sectional view taken along line X-X arrow view (B), the decomposition gas conduit L ₂ and L ₃ to conduct decomposition gas (dry distillation gas), concentrically with a predetermined gap g in its outer periphery It consists arranged the insulated pipe P ₂ and P ₃ Prefecture, the gap g to heat insulation cracked gas conduit by introducing a hot gas.

In the present embodiment, the hot gas introduced into each of the cracked gas conduits L ₂ and L ₃ is supplied from the gas pipe L ₄ for sending the exhaust gas from the cracked gas combustion furnace 30 to the cyclone 31 through the blowers 38, 3.
By 8 'fed from respective insulated pipe P _2, one end of the P ₃ (decomposed gas combustion furnace 30 side) in the gap g, is derived through the gas pipe L ₅ from the other end (derivation duct 20 side), Send to cyclone 31.

At this time, fresh air 39 and 39 'are introduced to maintain the temperature at a temperature at which the tar content does not solidify, that is, at a temperature not lower than the temperature of the decomposition gas generated from the material to be treated.

Next, an operation method in the thermal decomposition processing facility will be described.

First, the fuel such as LNG is burned in the hot blast stove 23 to generate hot gas, and the circulation blower 27 is operated to introduce the hot gas into the gas duct 18b of the carbonization furnace 18 and the gas duct 15b of the desalination furnace 15. , Each rotating cylinder 18a
And 15a are heated.

The heating temperature for the dechlorination treatment is 250 ° C.
~ 350 ° C, heating temperature for carbonization is 450 ° C ~ 65
When the temperature is set to 0 ° C., first, the carbonizing furnace 18 is set at 450 ° C. to 650 ° C.
And the heated hot gas is passed from the connecting pipe 24 to the desalination furnace 15.
To be introduced. At this time, the air for temperature control 2
5, the temperature of the desalination furnace 15 is adjusted to 250 ° C. to 350 ° C.

Next, the object to be treated is charged into the crushing means 1 and crushed to a predetermined size (30 mm or less). Then, iron-based metals such as nails are removed by the metal removing means 2, and the metal is conveyed to the hopper 10 by the first closed conveying means 4 and temporarily stored.

Next, the hopper 10 is introduced from the lower part of the hopper 10 to the first fixed-quantity supply means 12 via the second closed conveyance means 11,
Here, a predetermined amount (a quantification of the input amount) is supplied to the desalination furnace 15 by weighing. At this time, the treatment agent 14 for dechlorination is injected into the second closed conveyance means 11. The object to be processed, the object to be processed and the processing agent are agitated and mixed by the second closed transport means 11 in the transport process.

The heat treatment in the desalination furnace 15 is performed according to the temperature and time at which harmful substances (such as hydrogen chloride) contained in the material to be treated precipitate. The temperature and time are investigated in advance to grasp the properties of the object to be treated, and the treatment is performed at a temperature (200 ° C. to 350 ° C., about 30 minutes) and time that can sufficiently cover the result of the investigation.

The heat treatment in the desalination furnace 15 and the carbonization furnace 18 is not a combustion and incineration, but a steaming in a low-oxygen atmosphere and a thermal decomposition, and a halogen-based substance deposited by the thermal decomposition. A harmful substance (HCl gas or the like) is brought into contact with the treating agent.

As the treating agent to be mixed or added with the article to be treated, use is made of an alkaline substance which reacts with at least HCl (hydrogen chloride) to produce harmless chloride. For example, JP-A-9-155326, JP-A-10-43713, JP-A-10-235186, which the applicant of the present application previously filed,
JP-A-10-235187, JP-A-11-9937
As shown in JP-A-11-101417, alkaline earth metals, alkaline earth metal compounds, alkali metals,
Alkali metal compound, specifically, calcium, lime, slaked lime, calcium carbonate, dolomite, silicate (such as calcium silicate), sodium hydrogen carbonate, sodium carbonate, sodium sesquicarbonate, natural soda, sodium hydroxide, potassium hydroxide , Potassium bicarbonate or potassium carbonate, or a mixture of several types. The amount used is 5 to 30% by weight based on the object to be treated.
Is mixed or added.

As described above, for example, sodium hydrogen carbonate (NaH
When using CO ₃ ), HCl is used in the desalination furnace 15.
Decomposition gas of the component is generated, but immediately reacts with sodium hydrogen carbonate to (NaHCO ₃ ) + (HCl) → (NaC
l) + (H ₂ O) + (CO ₂ ) to produce harmless sodium chloride (NaCl),
Disappears. Thereby, detoxification of the HCl component in the decomposition gas and detoxification of the object to be processed after the heat treatment are simultaneously performed.

The detoxified object is sent into the rotating cylindrical body 18a of the carbonization furnace 18 through the lead-in / out duct 20, where it is carbonized at a temperature (350 ° C. for papers).
The carbonization starts at a degree. ) Carbonization treatment at 350 ° C to 700 ° C, preferably 600 ° C.

The carbonized object to be treated (carbide) is introduced into the cracked gas combustion furnace 30 via the second constant-quantity supply means 22, the third closed conveying means 28 and the third constant-quantity supply means 29, and is burned. . On the other hand, cracked gas (dry distillation gas) generated in the desalination furnace 15 and the carbonization furnace 18 is also introduced into the cracked gas combustion furnace 30, and both are burned (at 800 ° C. for 2 seconds or more) to incinerate the carbide. . The exhaust gas generated by this combustion process is discharged into the atmosphere via the cyclone 31, the heat exchanger 26, the bag filter 32, and the silencer 33.

[0053] Some of the exhaust gas generated by the combustion process of the decomposition gas combustion furnace 30 (850 ° C.), by a blower 38, 38 '(air ejector) in the heat insulation pipe P _2, P ₃ which surrounds the decomposed gas tube Forced introduction. At this time, fresh air 39, 39 'is taken in to adjust the temperature (500 ° C to 6 ° C).
(50 ° C.).

The temperature of the decomposition gas generated from the object is
Although it depends on the quality of the material to be treated,
In the case of 450 ° C., the temperature of the hot gas introduced into the heat retaining tube is higher than that.

Next, the temperature relationship of the decomposition gas conduit will be described. FIG. 3 shows the temperature relationship between each furnace and the cracked gas conduit during the normal operation of the heat treatment facility. The horizontal axis represents the pyrolysis treatment furnace (abbreviated as pyrolysis furnace), the cracked gas conduit (abbreviated as gas conduit), and the cracked gas. The flow direction of the cracked gas in the combustion furnace (abbreviated as gas combustion furnace) is taken, and the temperature is taken on the vertical axis.

In the figure, A on the horizontal axis indicates a connecting portion between the pyrolysis furnace and the gas conduit (the gas inlet side of the gas conduit and the hot gas outlet side of the heat retention tube), and B indicates the gas in the gas conduit. (A) is the decomposition gas temperature (300 ° C to 450 ° C), b is the temperature of the gas conduit (500 ° C to 650 ° C), and c is the gas. The temperature of the exhaust gas from the combustion furnace (800 ° C. to 850 ° C.) is shown.

High-temperature hot gas from the gas-fired furnace is introduced into the heat-retaining tube as heat-retaining hot gas. For example, the hot-gas-introducing side of the heat-retaining tube is adjusted to 600 ° C. by the adjusting means and blown to the outlet side. Then, depending on conditions such as the amount of heat released, the amount used for heating the decomposed gas, and the length of the gas conduit, as shown by the line b, the inlet side of the gas conduit (the outlet side of the hot gas for keeping heat). ). Therefore, the temperature on the hot gas introduction side of the heat retaining tube is set so that the temperature does not become lower than the decomposition gas temperature on the inlet side of the gas conduit. When passing through the gas conduit, the cracked gas a rises due to heating by the gas conduit, and becomes higher than the initial cracked gas temperature.

If the temperature of the gas conduit is not kept or the temperature condition is incorrectly set, the temperature becomes lower than the temperature at which the decomposition gas is generated, as indicated by the dotted line. In the portion below this, the tar component and the sublimation substance are attached and solidified.

FIG. 4 shows the relationship between the temperature of each furnace and the gas pipe after the object to be treated is put into the pyrolysis furnace. When the object is stopped, the generation of the decomposition gas is stopped after a predetermined time, and the amount of the moving decomposition gas is extremely reduced. Therefore, since there is no cracked gas fluid as the non-heating medium, there is almost no difference in temperature from the gas conduit, and the temperature a of the cracked gas approaches the temperature b of the gas conduit.

FIG. 5 shows the temperature relationship between each furnace and the decomposition gas conduit in the stop operation of the heat treatment.

In the stopping operation, first, the heating of the pyrolysis furnace is stopped. Next, after a certain time, the combustion in the gas combustion furnace is stopped.

When the operation of the thermal cracking furnace is stopped, the temperature in the thermal cracking furnace gradually decreases, but the shutdown of the gas combustion furnace is delayed after the thermal cracking furnace is stopped, and the supply of the hot gas to the heat retaining pipe is continued. Thereby, the temperature of the gas conduit can be maintained at a temperature equal to or higher than the initial decomposition gas temperature.

An important point in this stopping operation is that the supply of the heat retaining gas to the gas conduit is not stopped in synchronization with the stop of the heating of the pyrolysis furnace.

After a short time after the supply of the object to be treated is stopped, the generation of the decomposition gas is stopped and the amount of the moving decomposition gas is extremely reduced (or eliminated). However, the sublimation substance floats and adheres to the pyrolysis furnace and the decomposition gas conduit. Could be.

Therefore, when the introduction of the heat-retaining gas is stopped in synchronization with the stoppage of the pyrolysis furnace, the temperature of the gas pipe decreases as shown by the dotted line in FIG. 5, and the sublimate and fine solids adhere and solidify on the wall surface. Evolve to do.

[0066]

As described above, according to the present invention, by keeping the temperature of the cracked gas conduit constant for a certain period of time after stopping the heating of the pyrolysis furnace, which is the time when the generation of the cracked gas is stopped, the inner wall of the cracked gas conduit is maintained. It is possible to prevent sublimates and fine solids from adhering, prevent the growth and solidification of the adhering substances, and suppress phenomena such as blockage of decomposition gas pipelines and local combustion.

Further, by continuing for a certain period of time after the operation of the cracked gas combustion furnace is stopped, the effect can be further effectively suppressed.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a thermal decomposition treatment facility of the present invention.

FIG. 2 is an explanatory view of a closed conveying means.

FIG. 3 is an explanatory view of the operation method of the present invention (during normal operation).

FIG. 4 is an explanatory view of the operation method of the present invention (after the stop of charging of the object).

FIG. 5 is an explanatory view of the operation method of the present invention (after the heating of the pyrolysis furnace is stopped).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Crushing means 2 ... Metal removal means 3 ... Container 4, 11, 28 ... Closed conveyance means 5 ... Endless pipeline 6 ... Flexible conveyance means 7 ... Drive source 8 ... Input port 9 ... Discharge port 10 ... Hopper 12, 22, 29: fixed-quantity supply means 14: treatment agent 15: desalination furnace 16: supply-side duct 17, 19: induction heating means 18 ... carbonization furnace 20: lead-in / out duct 21: discharge-side duct 23: hot-air stove 24: connecting pipe 25 ... air for temperature control 26 ... heat exchanger 27 ... circulation blower 30 ... cracked gas combustion furnace 31 ... cyclone 32 ... bag filter 33 ... silencer 34 ... exhaust blower 35 ... hot water utilization equipment 36 ... pump 37 ... ash collection means 38 … Blower L ₂ , L ₃ … Decomposition gas conduit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K061 AA23 AB02 AC01 BA03 CA07 FA02 FA10 FA11 3K065 AA23 AB02 AC01 BA03 HA01 HA03 HA05 3K078 AA03 BA02 CA02 CA07 CA21 CA24 4K056 AA12 BB03 CA20 DA02 DA22 DA34 FA08

Claims (5)

[Claims] 1. A conveying means for conveying an object to be processed, a thermal decomposition processing means for reducing the volume of the object by external indirect heating,
Residue processing means for collecting the generated residue, cracked gas burning means for burning the generated cracked gas, cracked gas conduit means for leading the cracked gas generated by the thermal cracking means to the cracked gas burning means, cracked gas burning means Exhaust gas blower means for exhausting the exhaust gas burned in the above, wherein the decomposition gas conduit means comprises a decomposition gas conduit and a heat retaining pipe surrounding the decomposition gas conduit, and the decomposition gas generated by the thermal decomposition treatment means in the heat retaining pipe. A pyrolysis treatment facility characterized in that a hot gas at a temperature or higher is introduced. 2. The thermal decomposition treatment facility according to claim 1, wherein the hot gas introduced into the heat retaining pipe is a hot gas obtained by a decomposition gas combustion means. 3. A conveying means for conveying the object, a thermal decomposition means for reducing the volume of the object by external indirect heating,
Residue processing means for collecting the generated residue, cracked gas burning means for burning the generated cracked gas, cracked gas conduit means for leading the cracked gas generated by the thermal cracking means to the cracked gas burning means, cracked gas burning means Exhaust blower means for exhausting the exhaust gas burned in the above, the cracked gas conduit means comprises a cracked gas conduit and a heat retaining pipe surrounding the cracked gas conduit,
Introduce a hot gas at a temperature equal to or higher than the temperature of the decomposition gas generated by the thermal decomposition processing means into the heat retaining pipe to keep the temperature warm.In the stop operation, the introduction of the heat gas to keep the heat is continued for a certain time after the thermal decomposition processing means stops heating. A method for operating a pyrolysis treatment facility, wherein the method is performed. 4. A conveying means for conveying the object to be processed, a thermal decomposition processing means for reducing the volume of the object by external indirect heating,
Residue processing means for collecting the generated residue, cracked gas burning means for burning the generated cracked gas, cracked gas conduit means for leading the cracked gas generated by the thermal cracking means to the cracked gas burning means, cracked gas burning means Exhaust blower means for exhausting the exhaust gas burned in, the cracked gas conduit means comprises a cracked gas conduit and a heat retaining pipe surrounding the cracked gas conduit,
Introducing a hot gas having a temperature equal to or higher than the temperature of the decomposition gas generated by the thermal decomposition processing means into the heat retaining pipe to keep the temperature warm, and in the stop operation, the introduction of the hot gas to be kept warm is performed after the heating of the thermal decomposition processing means is stopped. A method for operating a pyrolysis treatment facility, characterized in that the combustion of the combustion means is stopped and then performed continuously for a certain period of time. 5. The hot gas introduced into the heat retaining pipe is an exhaust gas obtained by a decomposition gas combustion means.
Or the operation method of the thermal decomposition treatment facility according to 4.