JP2002061814A - Method of heat treatment of substance to be treated containing combustibles, treating equipment and treating facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the blocking of the inside of a gas conduit by the hardening of a tar component by keeping the temperature of the gas conduit at an adequate temperature. SOLUTION: The hardening of the tar component is prevented by surrounding the outer part of a gas conduit with a warming jacket 50, introducing a hot gas from a decomposition gas burning furnace 6 into the warming jacket through a warming air introducing pipe 61, controlling the temperature of the introducing hot gas by controlling the capacity of a temperature controlling gas taken in from an air introducing pipe 63 and controlling the temperature inside the warming jacket 50 at the same temperature or higher than the temperature of the gas introduced into a combustible content removing means 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment method, a treatment apparatus, and a treatment facility for heat treating various objects containing a combustible component, and more particularly, to the removal of a combustible component from a decomposition gas generated during the heat treatment. The present invention relates to a means for preventing tar from being solidified when guided to the means.

[0002]

2. Description of the Related Art Various objects to be treated containing combustible components (for example, wastes, various 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 predetermined temperature conditions by indirect heating (for example, Japanese Patent Application Laid-Open No.
344213). Also, a batch type is known (Japanese Patent Application Laid-Open No. 6-269760).

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, to make the exhaust gas harmless, to make the residue harmless, and to reduce the damage of the treatment equipment due to chlorine. (See, for example,
155326, JP-A-10-43713, JP-A-10-235186, JP-A-10-235187, etc.).

[0006] Using these treatment agents, the material to be treated is heat-treated to obtain a carbide residue, and the carbide is used as a soil improvement material, a water purification agent, a snow melting agent, and a heat insulator due to its porous nature. It can also be used as a recycled product in a wide range of fields, such as being used as fuel.

[0007] In the case where the object to be treated is not subjected to the burning treatment but to the dry distillation treatment, the heat treatment generates a decomposed gas containing a combustible component such as tar, and the treatment is also required. . In particular, as shown in FIG. 3 and FIG. 4, there is a problem that tar is solidified and adhered to a gas conduit for introducing a decomposed gas containing a combustible component to the combustible component removing means in the next step, thereby blocking the conduit. .

FIG. 3 is a conceptual diagram of a well-known heat treatment facility for subjecting an object to be processed in a rotary kiln-type heat treatment furnace. The object to be processed 2 is charged into a heat treatment furnace 1 and a heating medium is supplied to an external heating means 1a. A hot air gas 3 is introduced and heated at a predetermined temperature to thermally decompose, and a residue (carbide) 4 after the treatment is taken out. On the other hand, the generated decomposition gas (dry distillation gas) is removed through a gas conduit 5 to remove combustible components. It is introduced into a cracked gas combustion furnace 6 as a means, and here, a tar component and harmful substances are burned by a gas burner 6B or the like. The burned gas is cooled by utilizing the heat in the heat exchanger 7, cleaned by the bag filter 8, and then discharged from the chimney 9. In the figure, B is a blower which sucks and discharges the carbonized gas generated in the heat treatment furnace 1 to perform the above series of processing.

When the object to be treated is heated in a heat treatment furnace by an external heating means and subjected to a thermal decomposition treatment such as a dry distillation treatment,
Decomposition gas (dry distillation gas) is generated, and such a generated gas is burned at 850 ° C. for 2 seconds or more and discharged.

[0010] The generated gas is entirely sucked by a blower B provided at a later stage as an exhaust gas system, and the inside thereof tends to have a negative pressure with respect to the atmospheric pressure. However, when a decomposition gas is generated in the heat treatment furnace or when the gas conduit 5 is closed, the pressure tends to be positive with respect to the atmospheric pressure.

A problem that arises when the pressure inside the heat treatment furnace becomes a positive pressure is gas leakage from a seal portion constituting the furnace. In particular, in the case of a rotary kiln (rotary type) having a rotating part seal, there is a possibility that decomposition gas leaks from the sealed part. In this case, the condition is constantly monitored, and if the pressure becomes positive, the suction force of the blower may be increased, but the monitoring and control become complicated.

[0012] When the air is strongly sucked by the blower, the inside of the decomposition gas combustion furnace becomes negative pressure, and the combustion state changes. That is, combustion at 850 ° C. for 2 seconds may be difficult. Therefore, (a) means for maintaining a negative pressure in the heat treatment furnace,
(B) How to prevent a change (decrease) in combustion conditions in a cracked gas combustion furnace is an important issue.

Therefore, the present inventors provide a means for introducing cracked gas into the cracked gas combustion furnace by suction using a driving gas to make the inside of the heat treatment furnace a negative pressure with respect to the atmospheric pressure. Thus, means for preventing the decomposition gas from leaking were attempted.

That is, FIG. 4 is an explanatory view of a heat treatment apparatus provided with the decomposition gas introducing means, in which two heat treatment furnaces, a first heat treatment furnace 10 and a second heat treatment furnace 20, are used. This is an example.

The first heat treatment furnace 10 includes a rotatable rotating cylinder 11, a heating jacket 12 for forming a gas duct on the outer periphery of the rotating cylinder 11, and heating the rotating cylinder 11 by introducing a hot gas. A supply port 13 provided at one end of the rotating cylindrical body 11 for supplying the object to be processed into the rotating cylindrical body 11, and a discharge port 14 provided at the other end of the rotating cylindrical body 11. The rotating cylinder 11 is driven to rotate by rotation driving means (not shown).

The rotation driving means of the rotating cylinder 11 is composed of a normal driving motor, a driving gear, a driven gear provided on the rotating cylinder, and the like. The heating jacket 12 is fixed, and a mechanical contact (not shown) is provided at a rotational contact portion with the rotating cylindrical body 11.

Reference numeral 15 denotes a supply port 13 of the first heat treatment furnace 10.
An object to be processed is introduced into the rotating cylinder 11 by a supply duct provided on the side. A support roller 17 rotatably supports the rotating cylindrical body.

The structure of the second heat treatment furnace 20 is substantially the same as the structure of the first heat treatment furnace 10, and includes a rotatable rotating cylinder 21 and a hot gas A heating jacket 22 for heating the rotating cylinder 21 by the introduction of the first cylinder, and one end of the rotating cylinder 21,
And a supply port 23 provided on the discharge port 14 side of the heat treatment furnace 10 for supplying an object to be processed into the rotary cylinder 21 and a discharge port 24 provided at the other end of the rotary cylinder 21. Have been.

Reference numeral 16 denotes an outlet 14 of the first heat treatment furnace 10.
Side and the supply port 23 side of the second heat treatment furnace 20,
1 shows an introduction duct for introducing an object to be processed in a first heat treatment furnace 10 from a first heat treatment furnace 10 to a second heat treatment furnace 20.

Reference numeral 25 denotes a dissolving tank (not shown) which surrounds the discharge port 24 side of the rotary cylindrical body 21 of the second heat treatment furnace 20 and heats the object (residue) heated in the second heat treatment furnace 20. It is a discharge side duct that discharges to the like.

Rotating cylindrical body 11 of first heat treatment furnace 10
And the rotating cylindrical body 21 of the second heat treatment furnace 20 are vertically arranged, and although not shown, the rotating cylindrical body 11
The heating jackets 12 and 21 provided on the outer periphery of the and 21 are supported and fixed by a fixing member, and a plurality of blades for transferring the object to be processed while stirring are provided inside the rotating cylinders 11 and 21. The mixture is transferred from the supply port 13 side to the discharge port 24 side by the rotation of the rotary cylinders 11 and 21 as shown by a dashed line in the figure.

Although not shown, a mechanical seal is applied to the contact portions of the ducts 15 and 16 that come into rotational contact with the rotary cylinder 11 and the contact portions of the ducts 16 and 25 that come into rotary contact with the rotary cylinder 21. ing.

Reference numeral 28 denotes a hot blast stove, for example, LNG, LP
A fuel such as G or petroleum is burned to generate hot gas.
This hot gas is supplied into a heating jacket 22 provided on the outer periphery of the rotating cylindrical body 21 of the second heating processing furnace 20 to heat the rotating cylindrical body 21, and then the first heating processing furnace is connected via the connecting pipe 26. It is fed into the heating jacket 12 of the rotating cylinder 11 of FIG. At this time, fresh cooling air 26a is taken into the communicator 26, and the temperature of the hot gas is adjusted.

Numeral 30 is a cracked gas combustion furnace, and 40 is a gas conduit through which cracked gas is passed.
Steam and decomposition gas generated in the first and second heat treatment furnaces are introduced from the lower suction portion 40b through the introduction duct 16,
It is introduced into the cracked gas combustion furnace 30 through the vertical portion 40c.
Reference numeral 41 denotes a decomposed gas introduction means, which is a case where the means is constituted by an air ejector. The decomposition gas introduction means 41 includes:
A gas introduction pipe 42, a nozzle member 43 provided in the gas introduction pipe 42, and a blower 44 for sending out a pressurized driving gas to the nozzle member 43, and one end of the gas introduction pipe 42 is connected to the decomposition gas combustion furnace 30. And the other end is connected to a gas conduit 40.
Is in communication with The tip end of the nozzle member 43 is narrowed and opened at the opening of the gas introduction pipe 42, and the other end is connected to a blower 44 so that gas is ejected from the tip end of the nozzle member 43 and suction of the jet flow is performed. -The cracked gas is attracted into the cracked gas combustion furnace 30 by the conveying force and burned in the combustion furnace.

Hi is a heat insulating material that surrounds the outer surfaces of the introduction duct 16 and the gas conduit 40 through which the decomposition gas passes, and keeps the temperature so that the inside is not cooled. In the gas conduit 40, the upper suction part 40a, the lower suction part 40b, and the vertical part 40c are connected, and the lower part of the vertical part 40c is connected to the gas introduction pipe 42.

[0026]

As shown in FIG. 4, when the heat insulation means surrounds the gas conduit through which the decomposed gas passes with a heat insulating material, there is no problem in a normal operation state, but the decomposed gas itself has no problem. Since the gas pipe is warmed and held at the temperature, the tar is attached and solidified in the initial stage because the temperature of the gas pipe is still low in the early stage when the decomposition gas is generated by operating and charging the material to be treated. In addition, it is necessary that the entire gas conduit be kept warm, and if there are intermittent temperature differences such as low-temperature parts and heat-retaining parts, there is a possibility that it will adhere to the low-temperature parts. And a portion where the protruding portion channel and the channel area change (for example, 40a, 40b,
It has been clarified by a number of experiments that there is a high possibility of adhesion to a portion that becomes a curved path of 40c).

Therefore, a heating jacket was provided outside the gas conduit, hot air gas was introduced into the heating jacket to try to keep the temperature, the operation was continued for a predetermined period, and after the operation was stopped, a decomposition inspection was performed. As a result, improvement was observed. However, the presence of the deposit was also confirmed.

As a means for removing combustible components such as tar components in the cracked gas, the combustion treatment is generally performed as described above. However, instead of burning, the oil is recovered as oil by an oiling device. There is also a means to remove. Also in this case, the same problem as in the case of combustion occurs because the gas is guided from the heat treatment furnace to the oiling device by the gas conduit.

The present invention has been made in view of the above-described problems, and has as its object to prevent tar from adhering and solidifying to a gas conduit and blocking the gas conduit.

[0030]

When an object to be treated containing a combustible component is heat-treated at a thermal decomposition temperature, a decomposition gas containing a combustible component such as tar is generated. (E.g., a combustible component removing means (for example, a combustion treatment in a cracked gas combustion furnace, or a treatment for recovering tar content (oilification) in a cracked gas in an oiling device)).

When the temperature of the gas conduit becomes, for example, 250 ° C. or less (depending on the unburned components in the gas), the combustible components (tar, oil) in the cracked gas solidify on the inner wall of the gas conduit, The inner diameter of the conduit may be reduced or, in the worst case, clogged, leading to an operation stop accident, and it is necessary to completely prevent solidification of tar.

As described above, even when the heating jacket is provided outside the gas conduit and hot air is passed through the heating jacket to keep the temperature, the tar component adheres and solidifies as described above. Although the temperature is kept by hot air gas, the temperature of the passing steam gas (for example, 30
0 ° C. or higher), and the temperature of the heat retaining gas was found to be lower (eg, 200 ° C.) than the temperature of the carbonized gas (eg, 600 ° C.), and it was found that the passing gas was being cooled.

Accordingly, the present invention prevents the adhesion and solidification of tar components by maintaining the temperature of the gas conduit which is easily cooled by the outside air at a temperature equal to or higher than the temperature of the steam / carbonized gas passing therethrough. Is to do so.

That is, a decomposition gas generated by heating an object to be treated containing a combustible component by a heat treatment unit is introduced into a combustible component removal unit of the next step through a gas conduit, and the combustible component removal unit is introduced. A method for removing combustible components contained in the decomposed gas by heating the outside of the gas conduit by heating and keeping the temperature at a temperature equal to or higher than the gas introduced into the combustible component removing means. It is characterized by.

As the object to be treated, plastics containing a large amount of combustible components and wastes containing plastics are particularly preferable.

In the heat treatment apparatus, a decomposition gas generated by heating an object to be treated containing a combustible component by a heat treatment unit is introduced into a combustible component removal unit in the next step through a gas conduit. What is claimed is: 1. A processing device for removing a combustible component contained in a decomposed gas by a combustible component removing unit, wherein a gas passing through the gas conduit is provided outside a gas conduit located between the heat treatment unit and the combustible component removing unit. The apparatus is provided with a heating and heating means for heating and maintaining the temperature at a temperature equal to or higher than the temperature.

The above-mentioned heat treatment means is desirably indirect heating. Further, the combustible component removing means may be either a decomposition gas burning means or an oiling means.

[0038] The heat treatment facility for the object to be treated includes a heat treatment means for heating the object to be treated containing a combustible component;
A heat treatment comprising: a combustible component removing means for introducing a decomposition gas generated by the heat treatment means to remove a combustible component contained in the decomposition gas; and a means for purifying and discharging the gas after removing the combustible component. A facility, outside the gas conduit for introducing the decomposed gas generated by the heat treatment unit to the combustible component removing unit, a heating and heat retaining unit for heating and retaining at a temperature equal to or higher than the gas temperature passing through the gas conduit. A heating medium obtained in the heat treatment facility is introduced into the heating and heat keeping means to heat and keep the heat.

[0039]

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

FIG. 1 is a conceptual diagram of a heat treatment facility for treating an object containing a combustible component according to the present invention, and shows a case where the present invention is applied to the conventional example of FIG. Therefore, portions having the same names or the same functions as those in FIG. 3 are denoted by the same reference numerals, and detailed description is omitted.

Thus, the present invention surrounds the gas conduit 5,
A heat insulation jacket 50 for heating and maintaining the gas conduit is provided,
It is characterized in that a heat medium for heat insulation is introduced into the heat insulation jacket 50 by the heat insulation means 60 to heat and maintain the heat at a predetermined temperature.

The heating / insulating means 60 includes a heating jacket 50.
A heat conducting gas introduction pipe 61 for introducing a heat medium (hot gas in this example) into the inside and a gas conducted through the heat insulation jacket 50 are led out to the decomposition gas combustion furnace 6 via the blower 44 of the decomposition gas introduction means 41. A warming gas outlet pipe 62 for returning the introduced hot gas to the decomposition gas combustion furnace 6 and an air introducing pipe 63 provided on the warming gas introducing pipe 61 for introducing cooling air for temperature adjustment to adjust the temperature of the hot gas. The hot gas for heat retention is taken out of the decomposition gas combustion furnace 6 and introduced through a heat retention gas introduction pipe 61 as shown in FIG. 1, for example.

When the temperature of the cracked gas generated in the heat treatment furnace 1 is, for example, 350 ° C. and the temperature of the hot gas generated in the cracked gas combustion furnace 6 is 850 ° C., air is introduced from the air inlet pipe 63. Increase the temperature to 3
Adjust to a temperature not lower than 50 ° C (3350 ° C or higher). In the adjustment, the temperature in the gas conduit 5 and the temperature in the heat insulation jacket 50 are measured by a thermocouple or the like.

A heat insulating material layer Hi is provided on the outer periphery of the heat insulation jacket 50 for keeping the jacket warm and protecting workers.

The heat medium supplied to the heat insulation jacket 50 for heat insulation is not limited to the heat gas obtained by the above-described decomposition gas combustion furnace, but may be a part of the hot air gas from the hot air furnace or other heat medium. Use of heat sources installed in the heat treatment facility,
In addition, it is possible to use steam or the like obtained from a waste heat boiler or the like in the facility.

The hot blast gas 3 to be supplied to the heating jacket 1a of the heat treatment furnace 1 is taken out from the decomposition gas combustion furnace 6 and supplied as shown in FIG. Is also good. The temperature adjustment in this case is
The adjustment is performed by the introduction amount of the temperature adjusting air 3a.

In the drawing, M indicates a rotation driving means of the rotary cylinder 1b.

FIG. 2 shows an example in which the heat insulation jacket and the heat insulation means of the present invention are applied in place of the heat insulating material of the heat treatment apparatus of FIG. Therefore, parts having the same names or the same functions as those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted. The heat insulation jacket 50 and the heat insulation means 60, which are characteristic parts of the present invention, will be described in detail. I do.

In FIG. 2, reference numeral 50 denotes a heat insulation jacket. The heat insulation jacket 50 includes a duct heat insulation jacket 51 surrounding the outer periphery of the introduction duct 16, a conduit heat insulation jacket 52 surrounding the outer periphery of the gas conduit 40, and a decomposition gas introduction. Nozzle insulation jacket 53 surrounding the outer periphery of means 41
The duct heat insulation jacket 51 can be attached to and detached from the conduit heat insulation jacket 52 at a portion indicated by a dashed line a, and the conduit heat insulation jacket 52 and the nozzle heat insulation jacket 53 are indicated by a dotted line b. Attachment and removal are possible at the indicated portions, and the structure is such that maintenance of the heat insulation jacket 50 and replacement of constituent members can be easily performed.

The heating and heat retaining means 60 includes the decomposition gas combustion furnace 30.
The hot gas is discharged from the discharge side through the heat retaining gas introducing pipe 61 and introduced into the heat retaining jacket 50 to heat and maintain the gas conduit 40, and then, is led out from the heat retaining gas introducing pipe 62 to decompose the decomposition gas introducing means 41. Blower 44, nozzle member 4
3 so as to be reduced into the cracked gas combustion furnace 30. Adjustment of the temperature inside the heat retaining jacket 50 is performed by adjusting the amount of air introduced from the air introduction pipe 63 in the same manner as in FIG.

The means for adjusting the temperature of the heat medium introduced from the heat retaining gas introduction pipe 61 is not limited to the introduction of cooling air, but may be indirectly cooled using cooling water. It is appropriately selected depending on the heat medium to be used.

[0052]

As described above, according to the present invention, the gas (water vapor, steam,
(Decomposed gas) is heated and kept at a temperature higher than the passing gas temperature when heating and keeping the gas conduit leading to the next process, so that components such as tar in the decomposed gas adhere to the gas conduit. It does not solidify.

Therefore, the decrease in the amount of adhered and solidified portions of the gas conduit, such as the changing portion of the flow path (bent portion, etc.) and the protruding portion, is eliminated. Instability factors such as triggering can be eliminated, and stable operation of equipment and maintenance of facilities can be ensured.
It produces effects such as:

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a heat treatment facility for an object to be treated according to the present invention.

FIG. 2 is a conceptual diagram of a heat treatment apparatus according to the present invention.

FIG. 3 is a conceptual diagram of a conventional heat treatment facility for processing an object.

FIG. 4 is a conceptual diagram of a conventional heat treatment apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Heat processing furnace 2 ... Processing object 3 ... Hot air gas 4 ... Residue 5 ... Gas conduit 6 ... Cracking gas combustion furnace 7 ... Heat exchanger 10, 20 ... Heat processing furnace 11, 21 ... Rotating cylindrical body 12, 22 ... Heating jackets 13 and 23 Supply ports 14 and 24 Discharge ports 15 Supply duct 16 Introductory ducts 17 and 27 Support rollers 26 Communication pipes 28 Hot blast stove 29 Discharge pipes 30 Decomposition as combustible component removing means Gas combustion furnace 31 ... Gas burner 40 ... Gas conduit 41 ... Decomposition gas introduction means 42 ... Decomposition gas introduction pipe 43 ... Nozzle member 44 ... Blower 50 ... Heat insulation jacket 51 ... Duct insulation jacket 52 ... Conduit insulation jacket 53 ... Nozzle insulation Jacket 60: Heat insulation means 61: Heat insulation gas introduction pipe 62: Heat insulation gas outlet pipe 63: Air introduction pipe

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F27D 17/00 101 B09B 3/00 303E F term (Reference) 3K061 AA07 AA18 AA23 AB02 AC13 BA05 CA07 FA10 FA21 FA25 3K078 AA05 BA03 BA08 CA02 CA09 CA12 CA22 CA24 4D004 AA07 AC05 CA24 CA25 CA27 CA32 CA50 CB04 CB05 CB31 CB34 CB36 CB50 CC02 DA02 DA06 4F301 CA09 CA25 CA27 CA41 CA42 CA52 CA64 CA66 CA72 4K056 BA02 CA20 DA02 DA33

Claims (6)

[Claims] 1. A decomposed gas generated by heating an object to be treated containing a combustible component by a heat treatment unit is introduced into a combustible component removal unit of the next step through a gas conduit, and the combustible component removal unit is provided. A method for removing combustible components contained in the decomposed gas by heating the outside of the gas conduit to a temperature equal to or higher than that of the gas introduced into the combustible component removal means by heating and keeping means. A method for heat treating an object to be treated containing a combustible component. 2. The method according to claim 1, wherein the object to be treated is plastics or waste containing plastics. 3. Decomposed gas generated by heating an object to be treated containing a combustible component by a heat treatment unit is introduced into a combustible component removal unit of the next step through a gas conduit, and the combustible component removal unit is provided. A combustible component contained in the decomposed gas by the heat treatment means and the combustible component removing means, outside the gas conduit located between the gas conduit, the temperature of the gas flowing through the gas conduit is equal to A heat treatment apparatus for an object to be treated containing a combustible component, comprising a heat insulation means for heating and maintaining the temperature at a higher temperature. 4. The apparatus according to claim 3, wherein the heating means for heating the object to be processed is indirect heating. 5. The apparatus according to claim 3, wherein the combustible component removing means is a cracked gas burning means or an oil converting means. 6. A heat treatment means for heat-treating an object to be treated containing a combustible component, and a combustible component removing means for introducing a decomposition gas generated by the heat treatment means to remove a combustible component contained in the decomposition gas. And a heat treatment facility provided with a means for purifying and discharging the gas after removing the combustible component, outside the gas conduit for introducing the decomposed gas generated by the heat treatment means to the combustible component removal means, Heating means for heating and maintaining the temperature at a temperature equal to or higher than the temperature of the gas passing through the gas conduit, wherein a heating medium obtained in the heat treatment facility is introduced into the heating and heat maintaining means to heat and keep the temperature. A heat treatment facility for an object to be treated containing a combustible component.