JP2000273460A - Synthetic coalification method for combustible waste and synthetic coalification equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To recycle combustible waste as easy-to-handle and highly flammable fuel. SOLUTION: The combustible waste is crushed by crushing means 3 and dried to a water content of about 10% by drying means 6;
, And dried to a moisture content of several% while mixing and transferring at the pre-stage and heated to about 200 ° C.
Decomposition and melting and carbonization under dilute oxygen while mixing and kneading while maintaining the temperature, kneading and homogenizing decomposition gases, molten plastics and carbides under pressure, and 100 ° C while kneading and transferring in the subsequent stage
It is rapidly cooled to the extent and discharged from the tip portion 29 as a coal-like material. [Effect] It is possible to efficiently obtain a highly practical solid fuel that has no odor, has good handleability, and is excellent in both ignitability and calorific value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic coalification method and a synthetic coalification apparatus for coalizing waste separated and collected as combustible waste in general waste.

[0002]

2. Description of the Related Art Combustible waste such as paper, wood chips, plastics, kitchen waste, etc. in general waste are mostly collected and separated as combustible waste in many municipalities and then incinerated. . In this incineration process, the high water content of the waste and the insufficient flammability make it necessary to use an auxiliary fuel because the calorific value is low and it is difficult to completely burn it. Inefficient processing has also been performed. On the other hand, in recent years, a method of reducing the volume of this combustible waste or recovering it as a solid fuel and recycling it has been put to practical use. As one of the typical methods, after crushing waste, it is kneaded and transferred by a screw-type extruder, and utilizes the pressurizing action of the extruder and the temperature rise of the material by self-heating. Then, there is a method in which the plastic in the material is melt-compressed and formed into a granular solid fuel. In addition, a method has been developed in which quicklime is added to the crushed combustible waste, mixed and treated, further compressed and kneaded by a molding machine to granulate, and dried to obtain a solid fuel.

[0003]

However, in the conventional incineration of combustible waste, the water content of the waste is 50 to 50%.
Since it is processed as it is as large as 60%, and is processed as it is in its original size, the calorific value is relatively low, 1000-2000 kcal / kg, and the qualitative fluctuation including composition is large, so that stable processing operation is difficult, and The reality is that utilization efficiency is low.
On the other hand, in the method in which flammable waste is crushed and adjusted as it is and melt-compression-molded in an extruder to obtain a solid fuel, the temperature rise of the material in the extruder remains at about 200 ° C. due to kneading and compression. Although the material is dried, paper, kitchen waste, and the like other than the molten plastic hardly change qualitatively. For this reason, the calorific value of the obtained fuel is as low as about 3500 kcal / kg, and its ignitability is not good, so that its value as a fuel is insufficient. In addition, the fuel has an unpleasant odor, which causes handling problems. Further, when processing waste having a high water content, it is necessary to evaporate and evaporate water in an extruder to reduce the water content to about 10%, but the calorific value and evaporation area are insufficient. Therefore, this processing is difficult.

[0004] In the case of a method in which quicklime is added to combustible waste and granulated by a molding machine, a large amount of quicklime is used as an adjusting material, so that there is a problem in that the processing cost is high. Further, since the material temperature at the time of processing is about 200 ° C. or less, qualitative change of the material, that is, reforming as a solid fuel is not performed as in the above-described method, and the calorific value is about 4000 kcal / kg or less at the maximum. However, there are problems that the calorific value is low and the amount of residual ash increases. Accordingly, at present, there is no practical treatment method and apparatus that can recover and recycle combustible waste as solid fuel having high fuel value and good handling properties.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has an advantage in terms of synthetic fuel conversion of combustible waste from which solid fuel having good handleability and high fuel value can be efficiently obtained without increasing production costs. It is an object to provide a method and a synthetic coalification device.

[0006]

Means for Solving the Problems To solve the above problems, the first method of the present invention for synthesizing combustible waste into synthetic coal is described.
The invention discloses that flammable waste mainly composed of garbage, papers, plastics, and the like is crushed and dried to a water content of about 10%, and then quantitatively supplied to a twin-screw extruder. ℃ and dried to a water content of a few% while mixing and transferring,
Then, in the middle stage, the mixture is decomposed and melted and carbonized under dilute oxygen while maintaining the temperature raised to about 300 ° C and kneading and transporting, and further, the decomposed gas, molten plastics, garbage and other carbides are kneaded and homogenized under pressure, and the semi-molten material Finally, the material is rapidly cooled to about 100 ° C. while kneading and transferring the material at a later stage, and is discharged as a solid coal-like material from the front end.

According to a second aspect of the present invention, there is provided the method for synthesizing combustible waste according to the first aspect of the present invention. It is characterized in that it is supplied to a hot air generator for drying treatment of combustible waste in the pretreatment of the screw extruder, burned, and used as a part of a heat source.

[0008] Further, the apparatus for synthesizing combustible waste of the present invention comprises a crushing means for crushing combustible waste mainly composed of garbage, papers, plastics and the like, and a crushable combustible waste. And a twin-screw extruder that performs drying, melting, and cooling while kneading and transferring the dried combustible waste, and the twin-screw extruder has at least three extruders in the extrusion direction. Zones are assigned and a heating / cooling control device that controls the temperature in the cylinder in accordance with each zone is provided, and the zone on the waste input side of the zone is a temperature at which the waste does not melt. And a drying zone in which the moisture content is reduced to several percent by heating, and the zone on the extrusion direction side of this zone is heated and held at a high temperature under a dilute oxygen atmosphere to decompose and melt the waste. Charcoal And a melting / carbonizing zone for kneading and homogenizing cracked gas, molten plastic, and garbage carbide in a pressurized state, and a zone on the extrusion direction side rapidly cools the semi-molten material to obtain a solid material. It is characterized by comprising a cooling zone.

The present invention is directed to combustible waste mainly composed of papers, kitchen wastes, plastics, and the like, which are generally separated and collected as combustible waste. The combustible waste used in the present invention is compositionally diverse, and its shape is wide ranging from a large one of several tens of centimeters to a powdery one or a film-like one. Is not limited.
In the present invention, the type and the mixing ratio of the combustible waste are not particularly limited, but are usually discarded as garbage and include biological materials and plastics.

When the above waste is treated by a twin screw extruder,
Normally, it is necessary to feed the twin-screw extruder quantitatively. As a supply means, a belt type, a screw type, and the like can be considered, but stable and quantitative supply is difficult with a wide range of shape characteristics such as the above-mentioned waste,
There is no supply feeder applicable in the state of the art. Therefore, in the present invention, a crushing means such as a multi-stage cutter type is provided to crush the waste, so that the waste can be stably and quantitatively supplied by a screw type feeder or the like. In addition, crushing the waste makes it possible to treat the waste well in the twin-screw extruder.

The size of crushing by the crushing means is not particularly limited, but is desirably several tens of mm or less, preferably 10 mm or less. Examples of the crushing means include a multi-stage cutter-type crusher.
The structure is not particularly limited. The crushed waste is dried by a drying means such as a hot air dryer. The combustible waste usually contains about 50 to 60% of water, and the water content of the waste is reduced to about 10% by the above-mentioned drying means before the treatment by the twin-screw extruder. Preferably, the water content is 10% or less. Examples of the drying means include a kiln-type hot-air dryer and the like.
The type and structure of the drying means are not particularly limited in the present invention.

Since the water content of the waste is low before the twin-screw extruder is charged as described above, the treatment by the twin-screw extruder described later is surely performed. That is, when the drying treatment is performed by the twin-screw extruder, the moisture in the material is evaporated and evaporated by mixing, heating, and deaeration with a vent. As it is, waste usually contains 50% or more of moisture. Conventionally, the waste is directly supplied to a twin-screw extruder for drying treatment.
The reduction in moisture content is not significant. To compensate for this, it is conceivable to increase the heating capacity of the extruder. However, 50
Waste containing more than 10% water by twin screw extruder about 10%
When the drying process is performed to a certain moisture content, a large amount of water vapor is generated in the extruder, and an abnormal pressure rise and pressure fluctuation occur in combination with the mixed flow of heterogeneous solid materials, resulting in stable processing of the materials. Becomes difficult. In addition, since the evaporating area of the material in the extruder and the heating area of the cylinder portion are insufficient, a predetermined amount of processing cannot be performed, and as a result, the processing amount is extremely reduced. In the present invention, in order to eliminate such inconveniences, after the waste is crushed, the moisture content is reduced by a drying device such as a kiln using a hot air system or the like before the treatment with a twin-screw extruder.

The crushed and dried combustible waste is supplied to a twin-screw extruder preferably using a fixed feeder such as a hopper. The twin-screw extruder has a twin-screw screw disposed in an extruder cylinder, and the screw is full flight, reverse flight, square flight, kneading, etc. so as to conform to the processing conditions of the three zones described later. It is configured by appropriately combining segment types. Further, by supplying a heating medium from the heating / cooling control device to the cylinder portion, the material temperature is controlled in each of the first stage, the middle stage, and the second stage in accordance with the zone. In the heating / cooling control device, the temperature is controlled by the type of the heat medium to be used and the temperature adjustment by the heating means.

(Drying Zone) As shown in FIG. 1, the input side of the waste consists of a drying zone which is heated to a temperature at which the waste does not melt to reduce the water content of the waste. In this zone, the waste is kneaded, transported, and refined. Therefore, the screws included in this zone have a screw structure suitable for mixing, transferring, and miniaturization. In this cylinder, the temperature of the waste increases due to frictional heat generated by heating and kneading by the heating / cooling control device provided in the cylinder portion, and the temperature is desirably set to a temperature at which the waste does not melt. Further, although the decomposition of waste is not the object of this zone, mild decomposition may occur (preferably a temperature at which a full-scale decomposition reaction does not occur). On the other hand, if the temperature is too low, the amount of heat required for drying is insufficient, so it is necessary to raise the temperature to a certain level. From such a viewpoint, heating is performed at about 200 ° C. in this zone. Preferably it is 180-200 degreeC. Since this temperature is the target temperature, a zone that does not reach this temperature may be included in the zone.

[0015] In this zone, the waste is dried to further reduce the waste moisture content that was reduced prior to input to the extruder.
If the reduction of the water content is insufficient, steam is generated more than expected in a rear zone in the extruder, and it becomes difficult to perform uniform kneading. Therefore, in this zone, the water content is reduced to about several percent. Preferably, the water content is 5% or less. Also,
Excessive drying only increases the load on the extruder and saturates the effect of homogenous kneading, so the lower limit of the water content can be 1% or more. In addition, it is desirable to provide a vent located at the end of this zone for extracting evaporated water generated during drying of the waste. Vapor generated by heating and drying can be sucked and exhausted through this vent. The gas exhausted from this zone also contains flammable gas due to slight decomposition as described above. Therefore, this gas can be recovered and supplied to the above-mentioned drying means to be used as a part of the fuel. This enables processing with high energy efficiency. The collection and supply of the gas is performed by a collection and supply unit including, for example, a pipe and a blower.

(Melting / Carburizing Zone) Next, on the extrusion direction side of the above zone, as shown in FIG. 1, the dried waste is heated and maintained at a high temperature under dilute oxygen to decompose and melt and carbonize the waste. A melting / carbonization zone for obtaining a semi-molten material by kneading and homogenizing cracked gas, molten plastic, and garbage carbide in a pressurized state. In this zone, the waste is kneaded, transferred, and compressed under pressure as described above, so that the screw has a structure adapted to this. In this zone, among the wastes, plastics in particular are brought into a molten state, and garbage such as kitchen wastes, and wastes made of biological materials such as papers are decomposed and carbonized. Therefore, in this zone,
Kneading is performed at a temperature considerably higher than the above zone. If the temperature is too low, the above-mentioned melting, decomposition, and carbonization are not satisfactorily performed. On the other hand, if it is too high, gas / liquefaction due to thermal decomposition of plastics and excessive decomposition / gasification of biological materials occur. And it is desirable to heat and raise the temperature to about 300 ° C. Preferably 280-320
° C. Since this temperature is also the target temperature, a zone in which the temperature has not reached this temperature may be included in the zone. The heating can be performed by supplying a high-temperature heat medium to the cylinder from the heating / cooling control device.

Further, since this zone is under a dilute oxygen having a concentration of 1% or less, carbon dioxide gas due to oxidative decomposition of an organic material,
This is effective in preventing conversion to water and performing energy conversion by thermal decomposition. This dilute oxygen is achieved by filling the inside of the extruder with a semi-molten and fluid material in the melting and carbonizing zone, and shutting off the entrained and flowing air through the material supply hopper and drying zone. .

In this zone, plastics are melted, and organic acids, alcohols, tars, wood gases, polymers, etc. are generated from biological materials due to thermal denaturation or thermal decomposition of waste, and residual moisture is generated. Generates water vapor and the like, and carbonization of the biological material proceeds. Further, the pressure increases due to the transfer and compression action by the screw and the accumulation of generated gas. The pressurized decomposition gas is dissolved and contained in a material in a semi-molten state in which a molten plastic and a carbide are mixed, becomes a homogenized and stabilized material, and finally obtains a heat capacity and an ignition capacity of a fuel. Improve the performance. If the rising pressure at this time is too low, it is difficult to contain the decomposition gas in the material, and if the pressure is too high, blowing of the material from the vent portion, overload, etc. occur,
Stable operation becomes difficult. From these perspectives, the rising pressure is
30 to 40 atm is desirable, and preferably 35 atm. The pressure can be adjusted by the screw structure, but a cylinder for adjusting the pressure of the decomposition gas can be provided in the cylinder at the end of this zone to suppress the rising pressure. By the action of the vent, the pressure can be adjusted so that the rising pressure is suppressed to a predetermined pressure or less. Since gas containing a large amount of flammable components is discharged from this vent as described above, it can be recovered and supplied to the above-mentioned drying means and used as a part of fuel, similarly to the drying zone. . This allows for more energy efficient processing. The recovery and supply of the gas is performed by a recovery and supply unit including, for example, a pipe and a blower, as described above.

(Cooling zone) Further, the extrusion direction side is shown in FIG.
As shown in the figure, the solid material forming zone is obtained by kneading the semi-molten material and rapidly cooling it while transferring it to obtain a solid material. Screws included in this zone have a screw structure suitable for kneading and transfer. In this zone, the material is quenched to solidify the material and to suppress the volatilization of decomposition and volatilization, thereby obtaining a more stabilized material. If the temperature is not sufficiently low, a solid material cannot be obtained, and the burden on the subsequent steps increases, and the quality of the material is impaired due to the volatilization of decomposition and volatile components. On the other hand, when the temperature is too low, the fluidity of the material is extremely reduced, and an overload state occurs, so that stable processing cannot be performed. Therefore, the target temperature at the discharge end in this zone is set to about 100 ° C. or less. Preferably it is 60 to 80 ° C. This zone may include a cooling process at a temperature higher than the target temperature. The rapid cooling of the material
This can be achieved by supplying a low-temperature heat medium from the heating / cooling control device to the cylinder section. The cooled material can be discharged outside through a die provided at the tip in the extrusion direction.

For the material extruded from the extruder, a continuous air-cooled cooler is provided if necessary, and the processed material is cooled to around normal temperature (4).
(0-50 ° C). Thereafter, if desired, a crusher is provided to crush and granulate to obtain a granular (powder) coal-like solid fuel. FIG. 1 shows a schematic view of a form of carbonization by a twin-screw extruder.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to FIG. The storage tank 1 stores the combustible waste to be processed and supplies it to a subsequent process, and has a feeding device 1a disposed therein. Near the outlet of the storage tank 1, one end of the belt conveyor 2 faces.
A multi-stage cutter-type crusher 3 is disposed on the other end side of the belt conveyor 2 in the feed direction. At the outlet side of the crusher 3, a magnetic separator 4 for removing iron-based foreign matter from waste is installed. One end of a belt conveyor 5 is disposed near the exit of the magnetic separator 4, and the other end of the belt conveyor 5 in the feed direction faces the charging section of the kiln hot air dryer 6. The kiln type hot air dryer 6 has a hot air generator 7
The fuel feeder 8 and an exhaust pipe 37 described later are connected to the hot air generator 7. An exhaust pipe 11 provided with an exhaust blower 10 is connected to the kiln-type hot-air dryer 6, and the exhaust pipe 11 is connected to a deodorizer 12. One end of the belt conveyor 13 faces the discharge section of the kiln-type hot-air dryer 6, and a supply feeder 14 faces the other end of the belt conveyor 13 in the feeding direction. The outlet side of the feeder 14 faces a hopper 21 which is a constant-rate feeder of the twin-screw extruder 20.

The twin-screw extruder 20 has two cylinders 23 and 23 disposed in a cylinder 22. A driving device 24 for driving the screws 23 and 23 is provided outside the cylinder. As shown in FIG. 1, the inside of the cylinder is assigned three zones, that is, a drying zone, a melting / carbonizing zone, and a cooling zone from the hopper side to the outlet side. In the screw 23, 23, the portion corresponding to the drying zone has a screw structure suitable for kneading, transferring, and miniaturizing waste, and the portion corresponding to the melting / carbonizing zone corresponds to the waste material. It has a screw structure suitable for kneading, transferring, and pressurizing and compression, and a portion corresponding to the cooling zone has a screw structure suitable for kneading and transferring waste.

The cylinder 22 is a cylinder jacket 2
The heating medium unit 30 is connected to the cylinder jacket 25 through heating medium pipes 31a and 31b. More specifically, the heat medium unit includes a high-temperature side unit 30a for supplying a high-temperature heat medium and a low-temperature side unit 30b for supplying a low-temperature heat medium. The heating medium pipe 31a is connected so that a high-temperature medium is supplied to a portion corresponding to the drying zone and the melting / carbonization zone, and a low-temperature medium is supplied to a portion corresponding to the cooling zone.
The heating medium pipe 31b is connected. The heating / cooling control device is configured by the heating medium unit 30, the heating medium pipes 31a and 31b, a heating unit (not shown) and a temperature setting unit.

The cylinder 22 is provided with a moisture extraction vent 26 at a position corresponding to the end of the drying zone (extrusion side), and at a position corresponding to the end of the melting / carbonization zone at a pressure corresponding to the decomposition gas pressure. An adjustment vent 27 is provided. The vents 26 and 27 have exhaust pipes 33 and 34 respectively.
The exhaust pipe 34 is provided with an exhaust gas cooler 35 and a pressure regulating valve 36. Further, the exhaust pipes 33 and 34 are joined and connected to an exhaust pipe 37, and the exhaust pipe 37 is connected to the above-described hot air generator 7 via an exhaust gas blower 38. These exhaust pipes 33,
The exhaust gas cooler 35, the pressure regulating valve 36, the exhaust pipe 37, and the exhaust gas blower 38 constitute an exhaust gas collecting / supplying unit that collects the exhaust gas from the twin-screw extruder and supplies the exhaust gas to the drying unit. A die 29 is provided at the tip of the cylinder 22 in the extrusion direction, and an input portion of the material cooler 40 faces the discharge direction of the die 29.

A cooling blower 43 is connected to the material cooler 40 via an air pipe 42. A crusher 45 is disposed near the discharge section of the material cooler 40, and one end of a conveyor 46 is disposed on the discharge side of the crusher 45. A product hopper 50 is disposed at the other end of the conveyor 46 in the transfer direction. Product hopper 50
A discharge valve 51 is provided at the discharge port, and a measuring device 56 for placing a product bag 55 is disposed near the discharge port.

Next, a process for producing coal-like fuel using the above-described apparatus will be described. An appropriate combustible waste mainly composed of garbage, papers, plastics and the like is prepared and put into the storage tank 1. In the storage tank 1, the waste is gradually sent to the belt conveyor 2 by the feeding device 1 a and supplied to the crusher 3 by the belt conveyor 2. The crusher 3 crushes the waste into a material having a particle size of several tens mm or less. Next, this material is supplied to a magnetic separator 4 to remove iron-based foreign matter, and then supplied to a hot-air dryer 6 by a conveyor 5. In the hot air generator 7 connected to the hot air dryer 6, solid fuel is supplied by the fuel feeder 8, and the solid fuel is burned. In the state where the processing is already performed by the twin-screw extruder 20,
The exhaust gas generated and exhausted by the twin-screw extruder 20 is passed through an exhaust pipe 3.
The air is supplied into the hot air generator 7 by the blower blower 38 through 7, and the fuel is burned as a part of the fuel. The heat generated by the hot air generator 7 is supplied as hot air into the hot air dryer 6 and used for drying the waste inside. In the hot air dryer 6, the waste is dried until the water content of the waste becomes about 10%. Exhaust gas (including an odor component) generated by the hot air dryer 6 is sucked and discharged through an exhaust pipe 11 by the operation of an exhaust blower 10, and is deodorized by a deodorizer 12. The waste dried by the hot air dryer 6 is transferred to the belt conveyor 1
3 and is supplied to and stored in the supply feeder 14. In the supply feeder 14, this waste is quantitatively supplied to the hopper 21 of the twin-screw extruder 20.

In the twin-screw extruder 20, the screws 23, 23 are rotated by the driving device 24, and the heating medium is supplied to the cylinder jacket 25 by the heating medium unit 30 in accordance with each zone, thereby heating the inside of the cylinder 22. . That is, in a portion corresponding to the drying zone, the waste is heated through the cylinder jacket 25 by a heating medium of, for example, 350 ° C. supplied from the heating medium unit 30a via the pipe 31a, and the waste is heated to about 200 ° C. The operation by the shaft screws 23, 23 allows the materials to be mixed and homogenized and refined, and at the same time, the water evaporates and evaporates. This reduces the water content of the material to a few percent. In addition, this heating also causes slight decomposition, and a small amount of gas such as an organic acid is generated. These gases, including the air entrained in the feedstock, are discharged from the vent 26 for extracting water, transferred to the hot air generator 7 through the exhaust pipes 33 and 37 as described above, and used as a part of the heat source. .

Next, this material moves to the middle melting and carbonizing zone in the cylinder 22 and is supplied from the heat medium unit 30a through the pipe 31a in the same manner as described above.
Heated through the cylinder jacket 25 by the heat medium of ° C., the temperature of the waste material rises to about 300 ° C. in combination with the action of pressurization and compression by the screws 23, 23. In this zone, drying of the whole material, decomposition of paper, garbage, and the like, and melting of plastics are performed by operations using the twin screw 23. A large amount of organic acids, alcohols, tars, wood gases, and the like are generated from paper, kitchen waste, and the like, and carbonized in a form in which carbon is released. While the plastics are in a molten state, the pressure is 30 to 40 kg / c while the carbides of the biological material, the decomposition gas and the molten plastic are kneaded and transferred.
It is pressurized and compressed at m ² , and the polymer-based decomposed gas is liquefied and fused to form a semi-molten and homogenized material as a whole. The gas pressure at this time can be controlled so as not to exceed the upper limit by adjusting the pressure regulating valve 36 provided in the exhaust pipe 34. At this time, the decomposed gas existing over a certain pressure is transferred through the vent 27 and the exhaust pipe 34 together with the steam and entrained air generated during drying, and is cooled by the cooler 35.
After moving to the exhaust pipe 37 via the pressure regulating valve 36, it is sent to the hot air generator 7 together with the dry exhaust gas generated in the drying zone and collected from the vent 26, and is used as a part of a fuel source for hot air.

The material processed in the melting and carbonizing zone enters the cooling zone at last, and is kneaded and transported by the low temperature heating medium of about 50 ° C. supplied from the heating medium unit 30b through the pipe 31b while being cylinder jacketed. 25, and finally cooled to about 100 ° C. and discharged through a die 29 at the tip. In this operation,
By cooling the carbonized material of the biological material formed in the melting and carbonizing zone, the decomposition gas, and the mixed-phase semi-molten material of the molten plastic, the molten plastic is solidified and the decomposition gas is more completely liquefied and solidified, The result is a black coal-like material as a whole. This material is supplied to a cooling blower 4 through an air pipe 42 in a band-type air-cooled cooler 40.
Cooling air is blown by 3 to cool to about 40 ° C. The cooled material is further transferred to a crusher 45,
Crush into granules at 5. Thereafter, the product is transferred to the product hopper 50 by the conveyor 46, and the discharge valve 51 is adjusted and the weighing device 5 is adjusted.
6, the fixed amount is stored in the product bag 55 by weighing according to
It is shipped as a product, and a part is
Used as a solid fuel. The obtained product has no bad smell, is easy to handle, has good ignitability even when used as a fuel, and has a large amount of heat generation.

[0030]

EXAMPLES Next, an experiment was conducted to produce a coal-like fuel from combustible waste using the combustible waste 1 t / h having the composition shown in Table 1 in accordance with the apparatus and operation procedure in the above embodiment. . The combustible waste has a water content of 55% as it is, and is continuously dried to about 10% by a hot air dryer 6. In addition, as a solid fuel of the hot air generator 7 connected to the hot air dryer 6, a part of the fuel which is a product of the present apparatus was used. Next, in the drying treatment by the twin-screw extruder 22, about 22 kg / h of water was evaporated and reduced to a water content of 6%. In addition, a slight decomposition due to this heating generated a gas such as an organic acid of about 5 kg / h, and a total of about 28 kg / h of exhaust gas including about 1 kg / h of air accompanying the feedstock. This gas was used as a part of the heat source of the hot air generator 7 as described above. This material was further dried in the middle melting and carbonizing zone of the twin-screw extruder, and 25 kg / h of water was evaporated to reduce the water content from 6% to 0.68%. In this zone, about 35% of biological materials such as paper and kitchen waste were decomposed. In addition, about 26 k of the cracked gas existing in this zone over a certain pressure
g / h was discharged from the vent 27 together with about 25 kg / h of steam generated during drying and the accompanying air, and was used as a part of the fuel in the hot air generator 7 in the same manner as described above. As a result of the treatment by the twin-screw extruder 22, a black coal-like material was obtained at 422 kg / h (water content: 0.68%).

In the hot air generator 7, as described above, the vent exhaust gas from the twin screw extruder 22 is 80 kg / h (steam 47 kg / h, organic decomposition gas 31 kg / h, air 2 kg / h) and solid fuel is converted. The product is used. In consideration of this fuel balance, the throughput of the hot air dryer 6 is 1 t /
h, the required amount of heat when the water content is dried from 55% to a water content of 10% is about 5.8 × 10 ⁵ kc in consideration of heat loss.
al / h, and the calorific value of the vent exhaust gas is expected to be about 6000 kcal / kg on the basis of the decomposition gas, so that the heat of combustion is 31 kg / h × 6000 kcal / kg = 1.86.
× 10 ⁵ kcal / h. Therefore, assuming that the remaining heat is covered by solid fuel, this calorific value is 7
Assuming 100 kcal / kg, the required amount is (5.8
0-1.86) 10 ⁵ kcal / h ÷ 7100 kcal
/Kg=55.5 kg / h. Approximately 13% of the recovered solid fuel will be used for pre-drying the raw material, and all the fuel in the hot air generator can be covered by by-products and products obtained in the manufacturing process, and it has excellent energy efficiency. You can see that it is doing. Table 2 shows an example of the characteristics of the solid fuel obtained by this processing apparatus in comparison with ordinary coal. As is clear from the table, the coal-like material obtained by the present invention has a low content of moisture, ash and harmful substances, and has a calorific value equivalent to that of ordinary coal. Further, compared to the conventional solid fuel, there is almost no odor, the ignitability is good, and the calorific value is remarkably excellent.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

As described above, according to the present invention,
Combustible waste mainly composed of garbage, papers, plastics, etc. is crushed and dried to a water content of about 10%, then quantitatively supplied to a twin-screw extruder and heated and maintained at about 200 ° C in the former stage. Then, while mixing and transferring, the moisture content is dried to a few percent, and then the temperature is raised to about 300 ° C. in the middle stage, and the mixture is kneaded and transferred to perform decomposition melting and carbonization under dilute oxygen. Kneading and homogenizing garbage and other carbides to form a material in a semi-molten state, and finally kneading and transferring this material at a later stage while rapidly cooling it to about 100 ° C and discharging it from the tip as a solid coal-like material, It is possible to obtain a solid fuel which does not have a stable treatment without adding quicklime or the like and has a good ignitability and handleability and which can be stored for a long period of time without odor as compared with the conventional solid fuel. In addition, this fuel has a calorific value equal to or higher than that of ordinary coal fuel, has a low content of active and harmful substances, and has a very low ash content and high quality. Furthermore, drying, carbonization by twin screw extruder,
The application of a batch operation of cooling and the utilization of cracked exhaust gas as a by-product as a dry fuel enables efficient and economical treatment, realizing a highly practical solid fuel conversion system for combustible waste. Provision is possible.

[Brief description of the drawings]

FIG. 1 is a graph showing a processing zone in a twin-screw extruder of the present invention.

FIG. 2 is a system diagram of an apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Storage tank 3 Crusher 6 Kiln type hot air dryer 7 Hot air generator 8 Fuel feeder 14 Supply feeder 20 Twin screw extruder 23 Screw 25 Cylinder jacket 26 Vent for extracting moisture 27 Vent for decomposed gas pressure adjustment 29 Dies 30 Heat medium unit 30a High-temperature side unit 30b Low-temperature side unit 31a Heat medium pipe 31b Heat medium pipe 33 Exhaust pipe 34 Exhaust pipe 35 Exhaust gas cooler 36 Pressure regulator 37 Exhaust pipe 38 Exhaust gas blower 40 Material cooler 43 Cooling blower 45 Crusher

Continued on the front page (72) Inventor Yukie Otsuji 1-6-1, Funakoshi Minami, Aki-ku, Hiroshima City, Hiroshima Prefecture Inside Japan Steel Works, Ltd. (72) Inventor Noriaki Hashimoto 1-6-1, Funakoshi-minami, Aki-ku, Hiroshima City, Hiroshima Prefecture No. In Japan Steel Works, Ltd. (72) Inventor Kondo No. 1-1 Nikko-cho, Fuchu-shi, Tokyo F-term in Japan Steel Works, Ltd. (reference) 4D004 AA03 AA07 AA12 BA03 CA04 CA09 CA15 CA26 CA29 CA32 CA42 CA45 CA50 CB09 CB13 CB28 CB46 CC02 DA02 DA03 DA06 DA09 4H012 HA05 4H015 AA01 AA02 AA12 AA17 AB01 BA09 BA12 BB02 BB03 BB06 CB01

Claims (3)

[Claims] 1. A flammable waste mainly composed of garbage, papers, plastics, etc. is crushed and dried to a water content of about 10%, and then quantitatively supplied to a twin-screw extruder. 200
C. and dried to a moisture content of a few% while mixing and transferring. Decomposing and melting and carbonizing under dilute oxygen while mixing and transferring while maintaining the temperature at about 300 ° C. in the middle stage. Plastics, garbage and other carbides are kneaded and homogenized to form a semi-molten material. Finally, the material is rapidly cooled to about 100 ° C while kneading and transferring in the subsequent stage, and is discharged from the tip as a solid coal-like material. Method for converting flammable waste into synthetic coal 2. A drying and decomposing exhaust gas generated in a process of a twin-screw extruder is supplied to a hot-air generator for drying a combustible waste in a pretreatment of the twin-screw extruder, and is burned. The method for synthesizing combustible waste according to claim 1, wherein the method is used as coal. 3. A crushing means for crushing combustible waste mainly composed of garbage, papers, plastics, etc., a drying means for drying the crushed combustible waste, and a method for drying the combustible waste. While kneading and transferring, drying, melting, decomposing, carbonizing,
A twin-screw extruder that performs cooling, wherein the twin-screw extruder has a heating and cooling control device that controls at least three zones in the extrusion direction and controls the temperature in the cylinder in accordance with each zone. The zone on the waste input side of the zone comprises a drying zone for heating and maintaining the waste at a temperature at which the waste does not melt to reduce the moisture content to several percent, and in the extrusion direction more than this zone. The zone on the side heats and holds the dried waste at high temperature under dilute oxygen to decompose and melt and carbonize the waste, while kneading and homogenizing the cracked gas, molten plastic, and garbage carbide under pressure. Combustible waste synthetic coal characterized by comprising a melting and carbonizing zone, and further comprising a cooling zone for rapidly solidifying a semi-molten material to obtain a solid material, wherein a zone on the extrusion direction side is quenched. Equipment