JP2014005398A - Pyrolysis apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized pyrolysis apparatus that achieves large reduction of COgeneration, a short time and low energy cost for pyrolysis by subjecting a raw material including a polyester fiber product, a polyester mixed fiber spinning product and a polyester resin such as PET to pyrolysis under an oxygen-free atmosphere.SOLUTION: A pyrolysis apparatus includes: an outer pot 2 that is installed above a bottom heater 1 and has an exhaust port 9 at its upper right part; an inner pot 3 that is installed inside the outer pot 2 and filled with uniforms made of polyester, a pyrolysis raw material 4; an upper heater 5 above the uniforms; an outer pot lid 6 that is installed above the upper heater and seals and fixes the outer pot 2; a reflector plate 7 installed on the rear face of the outer pot lid 6; and a water supply unit 8 that is installed on the left side of a pyrolysis furnace body and supplies cooling water to the clearance between the inner pot 3 and the outer pot 2.

Description

The present invention significantly reduces the generation of CO2 by thermally decomposing raw materials containing polyester-based resins such as polyester fiber products, polyester blended products, and PET in an oxygen-free atmosphere. The present invention relates to a small thermal decomposition apparatus with low energy cost for decomposition.

  Polyester is a synthetic fiber that has developed greatly along with nylon and acrylic. Although it was the slowest industrialization of the three major synthetic fibers, the production volume has increased significantly due to outstanding cost performance, and now it has grown to account for more than half of the synthetic fiber production. Incidentally, the world's synthetic fiber production volume of 36.69 million tons in 2008 was 30.65 million tons, accounting for about 84%. Since polyester has many excellent physical properties, it is used in large quantities as PET bottles in bottles other than fibers.

Polyester fiber products and polyester blended products are used as uniforms by many companies and organizations including police and security companies. These uniforms are extremely dirty and damaged, and are incinerated when they cannot be reused. ing.
When 1 kg of polyester clothing is incinerated, about 2.5 kg to 3.0 kg of CO2 is generated. If one million tons of polyester clothing is incinerated annually, a large amount of CO2 of about 2.5 million to 3 million tons will be generated, and it is expected to be pyrolyzed without incineration from the viewpoint of preventing global warming. ing. However, polyester resins such as PET produce only sublimable crystals such as terephthalic acid and benzoic acid when thermally decomposed and block the piping, so the only current situation is to burn them as gas in an incinerator.

Terephthalic acid is a substance that sublimes at a temperature around 300 ° C. in an oxygen-free atmosphere, and benzoic acid is a substance that sublimes at a temperature around 100 ° C.
That is, terephthalic acid becomes a solid at a stroke without going through a liquid at 300 ° C or less in an oxygen-free atmosphere, and benzoic acid becomes a solid at once without going through a liquid at a temperature of 100 ° C or less. It is.

In fields other than polyester fiber products and polyester blended products, as plastic usage has increased in recent years, the amount of plastic discarded has become enormous, resulting in a shortage of landfill sites and the generation of harmful gases such as CO2 and dioxins due to incineration. It contributes to environmental problems. Despite this situation, polyester fiber products, polyester blended products, PET bottles, etc. are incinerated because of the reasons mentioned above, it is technically difficult to perform pyrolysis treatment. This is because the cost required for processing is high.

On the other hand, from the viewpoint of the reuse of resources, attempts have been made to thermally decompose and recover oil for plastic materials other than PET, but there is a problem that it is difficult to separate from plastic resin. Therefore, for the purpose of converting waste plastic material containing PET into oil, Patent Document 1 provides a precipitation tank in which the waste plastic material containing PET is thermally decomposed, and then the generated terephthalic acid is quenched and precipitated. Attempts have been made to extract oil from waste plastic material avoiding the trouble of acid blocking the piping. Similarly, Non-Patent Document 1 attempts to take out oil, benzene, and the like from a mixed plastic material containing PET by thermally decomposing PET and CaO in a steam atmosphere to suppress generation of terephthalic acid. In patent document 1 and non-patent document 1, when a polyester-based resin such as PET is thermally decomposed, the problem of generating a sublimable crystal such as terephthalic acid and closing the pipe is not completely solved. It has not yet been possible to break through the current situation of burning as gas in an incinerator.

Japanese Laid-Open Patent Publication No. 2004-256636

Materials and Processes, 2008, Vol. 21, NO. 2

The present invention pyrolyzes a pyrolysis material containing polyester resin such as polyester fiber products, polyester blended products, PET, etc. at a treatment cost equal to or lower than that of the conventional incineration method, and more than 90% of the conventional incineration method. The purpose is to reduce CO2. Specifically, the thermal decomposition treatment time per time is shortened to 3 hours or less, thereby reducing the size of the equipment and reducing the power consumption required for the thermal decomposition treatment of 1 kg to 0.5 Kwh or less, that is, the treatment. The purpose is to reduce the electricity bill to 10 yen / kg or less.

In order to solve the above problems, the basic structure of the present invention includes a pyrolysis furnace main body for pyrolyzing a pyrolysis raw material, and an exhaust device including an exhaust fan for exhausting the pyrolysis gas generated in the pyrolysis furnace main body to the outside. Water between the pyrolysis furnace main body and the exhaust device for preventing external air from entering the pyrolysis main body, cooling the pyrolysis gas, and guiding the cooled pyrolysis gas to the exhaust device A water sealing tank, the water sealing sealing device is provided with a water sealing tank, an exhaust gas introduction port for introducing pyrolysis gas into the water stored in the water sealing tank, and a lid for the water sealing tank, The furnace body is provided with an inner pot in which the pyrolysis raw material is put, an outer pot in which the inner pot is put, and an upper surface heater for heating the pyrolysis raw material put in the inner pot from above, and the radiation efficiency is 50% or more as the upper surface heater. , Preferably excellent radiation efficiency of 80% or more It has a structure provided with a heater.

As a means for thermally decomposing organic matter in an oxygen-free atmosphere, there is a system in which heated steam is injected into the pyrolysis furnace to expel the air inside and the pyrolysis raw material is heated. However, this system has the following three problems.
First, in order to generate heated steam, a separate expensive equipment is required. The second is to generate enormous energy loss by releasing heated steam having a large latent heat of 2253 KJ / Kg to the outside. The third is that when polyester resin such as polyester fiber products, polyester blended products, and PET is pyrolyzed with water vapor filled, the polyester is hydrolyzed, so more terephthalic acid is generated and the piping is likely to be blocked. It is to become.

In order to solve the above problem, in the present invention, a simple water seal sealing device is provided between the pyrolysis furnace main body and the exhaust device, and the water seal sealing device stores water for water sealing. This eliminates the entry of external air into the main body of the pyrolysis furnace, so that the pyrolysis raw material can be pyrolyzed in an almost oxygen-free atmosphere. With regard to the air that enters the interior of the apparatus at the beginning, the amount of CO2 generated can be reduced by reducing the initial residual air volume by reducing the space and size by eliminating the useless space inside the apparatus. Specifically, in the case of a small thermal decomposition apparatus that thermally decomposes a 200 kg polyester uniform, the amount of CO2 generated per 1 kg of polyester is greatly reduced to about 0.2 kg.

In order to solve the problem that sublimable crystals such as terephthalic acid and benzoic acid are generated and block the piping, in the present invention, the pyrolysis gas temperature remains at a high temperature of 300 ° C. or higher, which is the temperature at which terephthalic acid is deposited. A structure that rapidly cools in water or near the water surface was adopted. Thereby, the trouble that terephthalic acid and benzoic acid block the piping does not occur.

As a first measure for reducing the energy required for thermal decomposition, the present invention uses a thin metal plate having a thickness of 1 mm to 2 mm for the inner pot, the outer pot and the lid. As a result, the heat capacity of the pyrolysis furnace body is reduced, and as a result, the energy required for pyrolysis is reduced and the time required for pyrolysis is also reduced.

As a second measure to reduce the energy required for thermal decomposition, in the present invention, a heat insulating material having a small heat capacity and a good heat insulating property is provided on the side surface and bottom surface of the outer pan, and the heat capacity is similarly small and a heat insulating property on the lid. A structure in which a good heat insulating material is provided. As a result, the heat capacity of the pyrolysis furnace body is reduced, and as a result, the amount of heat released to the outside is reduced and the time required for pyrolysis is also shortened.

However, if the structure of the pyrolysis furnace main body is surrounded by a heat insulating material having good heat insulating properties as described above, the cooling time of the pyrolysis furnace main body heated to about 500 ° C. to 600 ° C. after the pyrolysis treatment becomes very long. A new problem arises. If the lid is opened in a high temperature state, the oxygen that has entered the furnace reacts with carbides and burns out, so that the furnace needs to be cooled to about 200 ° C. to 300 ° C. to open the lid.

In order to solve the above new problem, the present invention employs a double pan structure in which an inner pan and an outer pan are used, and a water supply device for supplying cooling water between the inner pan and the outer pan. The structure is provided. The supplied water takes heat from the inner pot and the outer pot and evaporates, so that cooling is possible in only 10 to 20 minutes, and the cooling time can be greatly shortened.

As a measure for shortening the time required for pyrolysis, the present invention has a structure in which a heater for heating the bottom surface, bottom surface, and side surface of the outer pot is provided together with the upper surface heater for heating the pyrolysis raw material put in the inner pot from above.
When a polyester uniform is placed in a pot-shaped container and heated strongly from the bottom, the polyester near the bottom is first liquefied. Since the liquefied polyester has a rapid improvement in heat transfer, heating of the uniform immersed in the liquefied polyester is promoted. The amount of polyester liquefied by heating is increased, and the uniform made of polyester placed in a pan-like container is liquefied in a short time in a virtuous cycle that heating to the uniform is further promoted.

The biggest problem when short-time treatment is performed in such a double pan structure is that when heated polyester liquefies at about 260 ° C. and gasification starts by heating from the bottom, coal tar In this way, bubbles with high viscosity are generated, rising from the bottom of the inner pot, overflowing from the inner pot and spilling into the outer pot. This is the same phenomenon as when miso soup is boiled in a pan and bubbles overflow from the pan. In order to solve such overflowing troubles from the inner pot, a method of gasifying slowly by slowing the heating from the bottom can be considered, but this method cannot perform the treatment for a short time. If the treatment is not possible for a short time, the amount of treatment per day is reduced and the high temperature state continues for a long time. Therefore, there is a fatal disadvantage that the heat energy released from the pyrolysis furnace body increases and the treatment cost increases. It will be.

In order to solve the above problems, the present invention has a structure in which a heater having excellent radiation efficiency of 50% or more, preferably 80% or more is provided as the upper surface heater.

1 is a TG-DTA graph of polyester, FIG. 2 is an SC-DSC graph of polyester, Table 1 is an endothermic data of polyester, and Table 2 is an exothermic data. According to FIG. 1, when polyester is heated, it begins to become liquid (endothermic reaction) at around 245.2 ° C., and when heated further, the weight starts to decrease from about 360 ° C. due to thermal decomposition and reaches 500 ° C. Then, the pyrolysis is almost completed, and about 16.5% of the polyester becomes charcoal (C), and the remaining 83.5% becomes the pyrolysis gas. In this heating process, an exothermic reaction starts at around 413.8 ° C.

  FIG. 2 is a graph measuring the detailed temperatures of the endothermic reaction and exothermic reaction. According to FIG. 2, liquefaction (endothermic reaction) starts at 225.1 ° C. to 247.5 ° C. and ends before 300 ° C. . Furthermore, it can be seen that the exothermic reaction starts at 370.6 ° C. to 409.9 ° C. and continues to temperatures exceeding 500 ° C.

  Tables 1 and 2 are tables in which specific heat amounts of the endothermic reaction and the exothermic reaction were measured. It can be seen from Table 1 that the heat quantity of the endothermic reaction is about -61 Kj / Kg, and Table 2 shows that the heat quantity of the exothermic reaction is 217 Kj / Kg to 285 Kj / Kg. Here, assuming that the calorific value of the exothermic reaction is 217 Kj / Kg, and calculating the rising temperature of the polyester generated by this calorific value, ΔT = 217 Kj / Kg ÷ 1.02 Kj / Kg / K = 213 deg. It shows that when heated, the temperature can be increased to 500 ° C. or more at once due to self-heating.

From the above, if a foam made of a polyester liquid of about 300 ° C. can be heated instantaneously up to 400 ° C. during the rise, the temperature of the raised foam rises to 500 ° C., and 16.5% becomes charcoal and becomes an inner pot. The remaining 83.5% becomes gas and proceeds from the exhaust port of the pyrolysis furnace body to the water sealing device, which is the next process. As a result, it overflows from the inner pot and solves the problem. I can do it.

At this time, if a general sheathed heater or the like is used as the top heater, the radiation rate is as small as about 10%, so that the radiation energy intensity for heating the foam made of the rising polyester liquid is insufficient and prevents the foam from rising. I can't solve the problem of bubbles overflowing from the inner pot. In order to solve such trouble, in the present invention, the upper surface heater has a structure using a heater having a radiation efficiency of 50% or more, preferably 80% or more, and having good radiation efficiency.

As a more preferable solution, in the present invention, for the purpose of efficiently reflecting the radiation energy radiated upward from the upper surface heater above the upper surface heater, the radiation efficiency is 50% or more, preferably 80% or more. The reflection plate is provided. As a result, the intensity of radiant energy for heating the rising foam of polyester liquid is further increased. As a result, even if the bottom surface is heated more strongly, the problem that the foam overflows from the inner pot can be solved. Is possible.

In order to easily separate the terephthalic acid precipitated in the water seal sealing device from the water, the present invention has a structure in which a throttle tube for preventing the diffusion of the pyrolysis gas is provided inside the exhaust gas inlet. Thereby, the diffusion of terephthalic acid is suppressed, and as a result, it becomes easy to precipitate as a large lump.

In the water seal sealing device, in order to prevent benzoic acid that has not precipitated in water from adhering around the exhaust port of the water seal tank or in the exhaust device, in the present invention, a plurality of benzoic acids are attached to the side surface or top surface of the exhaust gas inlet. It was set as the structure which provided the slit or the punch hole. By adopting the above-described structure, the pyrolysis gas always passes through the slit portion or the punch hole portion. The slit width or punch hole diameter at this time is preferably as thin as possible, but if it is too small, the problem of clogging of the slit due to precipitates occurs. Specifically, it is preferably about 1 mm to 2 mm. As a result, the size of the bubbles of the pyrolysis gas that proceeds in the form of bubbles in the water is reduced, and as a result, it is easily cooled and almost all benzoic acid is precipitated in the water.

  In the water-sealed sealing device, in order to make it easy to collect the precipitate deposited therein, the present invention has a structure in which an elevating device is provided at the lower part of the water-sealed tank. Since the water-sealed tank 14 is placed on the elevating device 18, the water-sealed tank 14 is lowered below the exhaust gas inlet 15 by lowering the elevating device 18 and is deposited in the water in the water-sealed tank 14. Collecting deposits.

In order to oxidize and decompose carbon monoxide generated at the time of pyrolysis, in the present invention, a heat exchanger main body and a heater for heating the heat exchanger main body are heated in order to heat the pyrolysis gas after leaving the exhaust device. And a catalyst for oxidizing and decomposing carbon monoxide and the like is provided after the heating device. This makes it possible to reduce the concentration of carbon monoxide generated during pyrolysis. Further, this catalyst can also oxidize and decompose malodorous components such as acetaldehyde.

As the structure of the heating device, in the present invention, a heat exchanger body having a large number of holes for allowing pyrolysis gas to pass in a linear direction of a cylindrical metal member is provided as the heat exchanger body, and the heat exchanger A structure in which a heater for heating is in close contact with the outer side in the circumferential direction of the main body is employed. At this time, it is possible to efficiently transfer the heat energy from the heater to the pyrolysis gas by making the heat exchanger main body a material having excellent thermal conductivity such as aluminum or copper.

According to the present invention, pyrolysis raw materials containing polyester fiber products such as polyester fiber products, polyester blended products, and PET are pyrolyzed at a processing cost equal to or lower than that of the conventional incineration method, and more than 90% of the conventional incineration method. It becomes possible to reduce CO2.
Specifically, by shortening the thermal decomposition processing time per time to within 3 hours, the equipment can be downsized and the power consumption required for the 1 kg thermal decomposition processing amount is 0.5 Kwh or less, that is, the processing. The required electricity bill can be reduced to 10 yen / Kg or less.
If the thermal decomposition processing time per time can be shortened to 3 hours or less, the processing amount per day can be covered by processing about three times a day even if the processing amount per time is small. In addition, if the treatment is performed three times a day, the remaining heat can be reused in the second and third treatments, thereby further reducing the processing cost. Moreover, the charcoal generated by the pyrolysis process can be recycled as a product such as high-performance charcoal.

It should be noted that the present invention has a function of preventing a trouble that the liquefied plastic material overflows from the inner pot during the thermal decomposition of the plastic material other than the polyester-based resin, and has a function that can be processed for a short time. It can be expected to be used as a thermal decomposition treatment device for garbage and plastic trays, and as a thermal decomposition treatment device for medical waste such as a syringe with an injection needle.

TG-DTA graph of polyester Polyester SC-DSC graph Front view of pyrolysis furnace body Front view explaining the action of the water seal sealing device Front view of water sealing device Front view of a water seal sealing device according to another embodiment Front view of exhaust system (a) Front view of heat exchanger (b) Plan view of heat exchanger

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 3 is a front view (cross section) of the pyrolysis furnace main body according to the present invention. With reference to FIG. 3, the structure of the pyrolysis furnace main body and the mechanism of pyrolysis and carbonization of polyester will be described.

  As shown in FIG. 3, an outer pan 2 having an exhaust port 9 in the upper right portion is provided at the upper part of the bottom heater 1, and the inside of the outer pan 2 is filled with a uniform made of polyester that is a pyrolysis raw material 4. A pan 3 is installed, an upper surface heater 5 is provided on the upper part of the uniform, an outer pan lid 6 for sealing and fixing the outer pan 2 is provided on the upper portion, and a reflection plate 7 is provided on the back surface of the outer pan lid 6. The water supply device 8 for supplying cooling water to the gap between the inner pot 3 and the outer pot 2 is provided on the left side of the pyrolysis furnace main body.

A Kanthal heater is used as the bottom heater 1, and the electric capacity is 18 Kw. As the upper surface heater 5, a Hilex heater excellent in radiation efficiency is used, and its electric capacity is 24 Kw. This Hilex heater has a radiation efficiency of about 80% because the surface is baked with a material having a high radiation efficiency.
The material of the reflecting plate 7 is stainless steel, and a material having high radiation efficiency is baked on the surface, so that the radiation efficiency is about 80%.
The material of the inner pot 3 is copper or stainless steel, and the plate thickness is made as thin as 1.0 mm in order to reduce the heat capacity. The material of the outer pan 2 is copper in consideration of thermal conductivity, and the plate thickness is 2.0 mm in order to keep the strength while reducing the heat capacity.
Of course, the heat insulating material 10 having a small heat capacity and good heat insulation is provided on the side surface and bottom surface of the outer pan, and the heat insulating material 11 having a small heat capacity and good heat insulation is also provided on the lid.

Next, the mechanism of thermal decomposition of polyester will be described.
When heating is started by the bottom heater 1 and the top heater 5, the heat energy of the bottom heater 1 is transmitted to the bottom of the inner pot 3 through the bottom of the outer pot 2, and finally the polyester uniform that is the pyrolysis raw material 4. To be told. The radiant energy of the upper surface heater 5 is directly transmitted to a polyester uniform. When the temperature rises and the polyester reaches about 260 ° C., the polyester liquefaction process begins. When the heating is further advanced, all of the polyester filled in the inner pot 3 is liquefied, the polyester liquefaction process is completed, and the liquefied polyester is accumulated at the bottom of the inner pot 3.

  When the polyester liquefaction process is completed and the bottom surface temperature of the outer pot 2 is heated to a temperature of 400 ° C. or higher at which the polyester liquid is thermally decomposed, the polyester liquid gasification process starts at the bottom of the inner pot 3 and bubbles are generated Begin to. This is the same phenomenon as when water in a pan is heated to 100 ° C. or higher, bubbles are generated at the bottom of the pan and boil. However, the difference from boiling water is that water is a free-flowing liquid, whereas polyester liquid has a high viscosity like coal tar, so the generated bubbles are hard to collapse and rise from the bottom of the inner pot. Trying to overflow outside of 3. This is the same phenomenon as when miso soup is boiled in a pan and bubbles overflow from the pan.

At this time, if a Hilex heater with a radiation efficiency of 80% is used as the upper surface heater, and the capacity is further increased to 24 Kw, bubbles made of polyester liquid rising from the bottom of the inner pot 3 are irradiated with radiation energy. Because it can be instantaneously heated to 400 ° C. or higher, it can be pyrolyzed without overflowing outside the inner pot 3.
Further, when the reflection plate 7 having a radiation efficiency of 80% is provided, the radiation energy radiated upward from the Hilex heater can be efficiently reflected, and the radiation energy intensity for heating the foam made of the polyester liquid can be increased. .

  Next, with the structure and thermal decomposition mechanism as described above, the specific target numerical value of the thermal decomposition processing time per time is within 3 hours and the power consumption required for 1 kg thermal decomposition processing is 0.5 Kwh or less, That is, a theoretical examination result as to whether the electricity cost required for processing can be 10 yen / Kg or less can be achieved.

First, the theoretical results of the feasibility of 0.5Kwh / Kg, which is the power consumption target, are given below.
(1) When the “required energy amount” required to convert 200 kg of polyester to a high temperature gas of 500 ° C. is obtained, F1 = 200 kg × (500 ° C.−25 ° C.) × 1.02 Kj / Kg / K = 98940 Kj .
(2) When the “endothermic energy amount” required for liquefying 200 kg of polyester is obtained, F 2 = 200 Kg × 61 Kj / Kg = 1200 Kj from the results shown in Table 1.
(3) From the results shown in Table 1, F3 = 200 kg × 217 Kj / Kg = 43400 Kj when the “heat generation energy amount” generated when gasifying 200 kg of polyester liquid is obtained.
In consideration of the values of (1), (2), and (3), when the “required energy amount” required until the polyester is changed to a high temperature gas of 500 ° C., F = F1 + F2−F3 = 67740 Kj.
Next, when the “input energy amount” when the power consumption target of 0.5 Kwh / Kg is input, F4 = 200 Kg × 0.5 Kwh / Kg × 3600 seconds / h = 360000 Kj.
From the above results, the ratio between “necessary energy amount” and “input energy amount” is as low as F ÷ F4 = 18.8%. That is, ignoring the heat capacity of the pyrolysis furnace body and the amount of heat released from the pyrolysis furnace body, the required power consumption is only 0.094 Kwh / Kg.
Here, when the heat capacity of the main body of the pyrolysis furnace is reduced and the heat insulation of the main body of the pyrolysis furnace is increased, the heating time (excluding the cooling time) during the pyrolysis process can be shortened to about 2.5 hours. The problem remains.

The following is the theoretical examination result of the feasibility of 3 hours, which is the target for the thermal decomposition treatment time.
(1) When “required energy amount” required to convert 200 kg of polyester into a 400 ° C. polyester liquid, F5 = 200 kg × (400 ° C.−25 ° C.) × 1.02 Kj / Kg / K = 76500 Kj .
(2) When the “endothermic energy amount” required for liquefying 200 kg of polyester is obtained, F6 = 200 Kg × 61 Kj / Kg = 1200 Kj from the results shown in Table 1.
(1) Taking into consideration the values of (2), when the “required energy amount” required for making the polyester into a 400 ° C. polyester liquid is obtained, F7 = F5 + F6 = 88700 Kj.
Assuming that the total electric capacity of the bottom heater and the top heater is 42 Kw, the time required to give the “required energy amount” is 88700 Kj ÷ 42 Kw = 35 minutes.
That is, if the heat capacity of the pyrolysis furnace main body and the amount of heat released from the pyrolysis furnace main body are ignored, the heating time for converting 200 kg of polyester into a 400 ° C. polyester liquid may be only about 35 minutes. From this result, if the heating time until the polyester is changed to a liquid polyester at 300 ° C. is 1.5 hours, the time until the liquid polyester is gasified is 1 hour, and finally the time required for cooling is 0.5 hours. The target 3 hours can be realized. Here, the cooling time can be cooled in 10 to 20 minutes by injecting cooling water. Moreover, since the heating time until the polyester is liquefied can also be 1.5 hours, the biggest problem is whether the time until the liquefied polyester is gasified can be completed in a short time of 1 hour. It is.
That is, it becomes a problem whether the liquefied polyester can be gasified in a short time of 1 hour while preventing the trouble that the liquefied polyester becomes bubbles and overflows from the inner pot.

About the above, the theoretical examination result about whether the liquefied polyester can be gasified in the short time of 1 hour is shown below, preventing the trouble that the liquefied polyester becomes foam and overflows from the inner pot.
First, when the amount of polyester foam rising from the bottom of the inner pot in the form of foam is obtained, G = 200 kg ÷ 60 minutes = 3.33 kg / min. Next, it will be examined whether all of the rising 3.33 kg / min polyester foam can be heated to 400 ° C. or more with the radiation energy from the “Hilex heater” and “reflection plate”.
(1) The amount of energy required to bring the polyester liquid at 300 ° C. to 400 ° C. is F8 = 3.3 Kg / min × (400 ° C.-300 ° C.) × 1.02 Kj / Kg = 337 Kj / min. .
(2) Given that about 50% of the radiant energy radiated from Hilex heater can be given to the polyester liquid, the amount of radiant energy received by the polyester liquid is calculated as follows: F9 = 24 Kw × 80% × 70% × 60 Seconds / minute = 806 Kj / minute.
From the above results, F8 << F9, and all the polyester foams at 300 ° C. can be heated to 400 ° C. or more without problems. The polyester liquid heated to 400 ° C. or higher changes to a gas having a high temperature of 500 ° C. or higher due to the heat generated by the heat generated thereafter, and the thermal decomposition ends without any problem.

  4 is a front view for explaining the operation of the water seal sealing device according to the present invention, FIG. 5 is a front view of the water seal sealing device used in the present invention, and FIG. 6 is a water seal in which a part of FIG. 5 is changed. FIG. 4, FIG. 5 and FIG. 6 are used to explain the structure and function of the water sealing device.

First, the basic structure and basic functions of the water seal sealing device will be described with reference to FIG.
As shown in FIG. 4, water for water sealing is stored in a water sealing tank 14 provided with an exhaust port 12 at the upper right part, and an exhaust gas inlet 15 is provided in such a form that the tip is submerged in the water. A water-seal tank lid 16 is provided on the water-seal tank 14, and the water-seal tank lid 16 has a two-part structure that can be separated into left and right. By adopting such a water-sealed structure, the penetration of external air into the pyrolysis furnace main body is eliminated, so that the pyrolysis raw material can be pyrolyzed in an almost oxygen-free atmosphere.
Of course, a heat insulating material 17 is provided outside the piping until the pyrolysis gas generated from the main body of the pyrolysis furnace is led to the exhaust gas inlet 15.

The pyrolysis gas enters the water in the form of bubbles from the front end of the exhaust gas inlet 15, passes through the outside of the exhaust gas inlet 15, and rises again on the water surface.
At this time, terephthalic acid and benzoic acid contained in the pyrolysis gas are cooled with water and deposited in water. The pyrolysis gas after depositing terephthalic acid and benzoic acid in water is sucked from the exhaust port 12 by a fan built in the exhaust device and proceeds to the exhaust device. At this time, by opening the gap between the lid divided into two, fresh air as well as the pyrolysis gas is sucked by the fan built in the exhaust device and proceeds to the exhaust device.

Next, the structure and function of the water seal sealing device used in the present invention will be described with reference to FIG.
As shown in FIG. 5, a water-sealed tank 14 having an exhaust port 12 in the upper right part and an overflow pipe 13 in the lower left part and a drain valve 21 in the lower right part is installed on the lifting device 18. Water sealing water is stored in the water sealing tank 14, an exhaust gas inlet 15 is provided in such a form that the tip is submerged in the water, and a water sealing tank lid 16 is provided on the water sealing tank 14. It has a structured.
Further, a throttle pipe 19 for preventing the diffusion of pyrolysis gas is provided inside the exhaust gas inlet 15, and a plurality of slits 20 are provided on the side surface of the exhaust gas inlet 15.

  The pyrolysis gas generated in the pyrolysis furnace main body is throttled by the throttle pipe 19 and then proceeds toward the water surface. By squeezing the pyrolysis gas, it is possible to prevent diffusion of the pyrolysis gas and to prevent terephthalic acid from adhering to the inner wall surface of the exhaust gas inlet 15, and to aggregate the terephthalic acid into a large aggregated precipitate. Next, the pyrolysis gas that has passed through the narrow slit on the side surface of the exhaust gas inlet 15 becomes a small bubble and passes over the outside of the exhaust gas inlet 15 and floats on the water surface. At this time, by making small bubbles, cooling in water proceeds and benzoic acid is easily precipitated in water. Deposits deposited in the water can be easily recovered by lowering the lifting device 18 and removing the lid 16 for the water seal tank. Further, the water in the water seal tank 14 can be drained by opening the drain valve 21.

  FIG. 6 shows an example in which the structure of the exhaust gas inlet 15 is changed. In this case, a plurality of punch holes 22 are provided on the upper surface of the exhaust gas inlet.

  FIG. 7 is a front view of the exhaust device according to the present invention. The structure and function of the exhaust device will be described with reference to FIG.

As shown in FIG. 7, the exhaust device body 22 includes a filter 23 and an exhaust fan 24. Further, the heat exchanger body 25 and the heat exchange are used to heat the pyrolysis gas that has exited the exhaust device body 22. A heater 26 for heating the vessel body 25 is provided, and a honeycomb catalyst 27 for oxidizing and decomposing carbon monoxide and the like is provided after the heat exchanger body 25. By adopting such a structure, precipitates that could not be removed by the water-sealing sealing device are removed by the filter 23, and finally carbon monoxide or the like generated by thermal decomposition is oxidized and decomposed by the catalyst 27 to obtain a carbon monoxide concentration. Can be exhausted to a concentration of 100 PPM or less.
As the catalyst at this time, Pt (platinum) was employed.

  Finally, the structure of the heat exchanger is shown in FIG. A heat exchanger main body 25 having a large number of holes for allowing pyrolysis gas to pass in a linear direction of a cylindrical metal member is provided using aluminum having a good thermal conductivity as a material, and the heat exchanger main body 25 is also provided. The heater 26 for heating is in close contact with the outer circumferential direction.

  As a result of thermal decomposition of a 200 kg polyester uniform using the thermal decomposition apparatus having the structure described above, it is possible to perform thermal decomposition processing within 3 hours without any trouble that the foam made of polyester liquid overflows from the inner pot. It becomes possible to make it within 0.5Kwh / Kg.

  DESCRIPTION OF SYMBOLS 1 ... Bottom heater, 2 ... Outer pan, 3 ... Inner pan, 4 ... Pyrolysis raw material, 5 ... Top heater, 6 ... Outer pan lid, 7 ... Reflection plate, 8 ... Water supply device, 9 ... Exhaust port, 10 ... Insulating material, 11 ... Insulating material, 12 ... Exhaust port, 13 ... Overflow pipe, 14 ... Water-sealed tank, 15 ... Exhaust gas inlet, 16 ... Lid for water-sealed tank, 17 ... Insulating material, 18 ... Lifting device, 19 ... Throttle tube, 20 ... slit, 21 ... drain valve, 22 ... punch hole, 23 ... exhaust device body, 24 ... filter, 25 ... exhaust fan, 26 ... heat exchanger body, 27 ... heater, 28 ... honeycomb-shaped catalyst,

Claims (10)

A pyrolysis furnace main body for pyrolyzing the pyrolysis raw material, an exhaust device including an exhaust fan for exhausting the pyrolysis gas generated in the pyrolysis furnace main body to the outside, and between the pyrolysis furnace main body and the exhaust device A water seal sealing device for preventing external air from entering the pyrolysis furnace body, cooling the pyrolysis gas, and guiding the cooled pyrolysis gas to an exhaust device. The sealing device is provided with a water-sealed tank, an exhaust gas introduction port for introducing pyrolysis gas into the water stored in the water-sealed tank, and a lid for the water-sealed tank. A pyrolysis apparatus comprising: a pan, an outer pan into which the inner pan is placed, and an upper surface heater for heating the pyrolysis raw material placed in the inner pan from above. 2. The thermal decomposition apparatus according to claim 1, wherein a heater having a radiation efficiency of 50% or more is provided as the upper surface heater. The thermal decomposition apparatus of Claim 1 or Claim 2 provided with the water supply apparatus for supplying the water for cooling between the said inner pot and the said outer pot. The thermal decomposition apparatus of any one of Claim 1 thru | or 3 WHEREIN: The heater which heats the bottom face or bottom face and side surface of the said outer pan was provided. 5. The thermal decomposition apparatus according to claim 1, wherein the radiation efficiency is 50 for the purpose of efficiently reflecting radiant energy radiated upward from the upper surface heater above the upper surface heater. 6. A thermal decomposition apparatus provided with a reflection plate excellent in radiation efficiency of at least%. The thermal decomposition apparatus according to any one of claims 1 to 5, wherein a throttle pipe for preventing diffusion of pyrolysis gas is provided inside the exhaust gas inlet. apparatus. The thermal decomposition apparatus according to any one of claims 1 to 6, wherein a plurality of slits or punch holes are provided on a side surface or an upper surface of the exhaust gas introduction port. The thermal decomposition apparatus according to any one of claims 1 to 7, wherein an elevating device is provided at a lower portion of the water-sealed tank. 9. The pyrolysis apparatus according to claim 1, wherein a heat exchanger main body and a heater for heating the heat exchanger main body are heated in order to heat the pyrolysis gas after exiting the exhaust device. 10. And a catalyst for oxidatively decomposing carbon monoxide or the like after the heating device. The thermal decomposition apparatus according to claim 9, wherein a heat exchanger main body having a large number of holes for allowing a thermal decomposition gas to pass is provided in the linear direction of a cylindrical metal member as the heating apparatus, and the heat exchange is performed. A thermal decomposition apparatus characterized in that a heater for heating is in close contact with the outer circumference of the vessel body.