JP5564994B2 - Pyrolysis carbide discharge cooling system - Google Patents

Description

  The present invention relates to a pyrolytic carbide discharge cooling system for cooling carbide generated by pyrolyzing waste or the like in a reducing atmosphere.

  As a method for treating waste such as municipal waste, there is a method of thermally decomposing waste in a pyrolysis furnace in a reducing atmosphere (see, for example, Patent Document 1). This treatment method can be used as a fuel gas because pyrolysis gas generated by pyrolysis is flammable, and can also be used as fuel because pyrolysis carbides generated by pyrolysis also have a high calorific value, It is excellent in terms of resource reuse.

By the way, the means for transporting the pyrolytic carbide discharged from the pyrolysis furnace does not want to let air flow into the pyrolysis furnace, so a screw conveyor is frequently used because of the relatively low air flow. Yes.
In addition, the pyrolytic carbide discharged from the pyrolysis furnace has a high temperature, and cooling treatment is generally performed in a screw conveyor in consideration of handling and safety in later processing.

  The conventional cooling system of the screw conveyor is a water cooling type, and as shown in FIG. 2A, the trough 51 of the screw conveyor 50 is made into a double pipe structure, and a cooling jacket 54 is provided between the outer cylinder 52 and the inner cylinder 53. In addition, the screw shaft 55 is a hollow shaft and the inside is used as a cooling passage 56, and cooling water is circulated through the cooling jacket 54 and the cooling passage 56.

JP 2003-24919 A

  However, the water-cooled cooling system not only requires the trough 51 of the screw conveyor 50 to have a double-pipe structure, but also requires a strict sealing structure to maintain the sealing performance of the cooling water. become. Further, since the trough 51 has a double tube structure, there is a disadvantage that the weight is increased.

  Further, as shown in FIG. 2B, a slight clearance is required between the inner cylinder 53 of the trough 51 of the screw conveyor 50 and the screw flight 57 in order to prevent foreign matter from being caught. The pyrolytic carbide C that has entered may stay without being conveyed. In such a case, the contact surface with the inner cylinder 53 in the pyrolytic carbide C, that is, the heat transfer surface is not renewed, and the pyrolytic carbide C Since the heat conductivity is low, the cooling through the inner cylinder 53 is not performed efficiently, and the cooling performance becomes insufficient.

  In addition, in order to move the pyrolytic carbide C staying between the inner cylinder 53 of the trough 51 and the screw flight 57, even if it is desired to apply vibration to the pyrolytic carbide C by striking the trough 51, the trough 51 Because of the double tube structure, it was difficult to vibrate the inner cylinder 53 in contact with the pyrolytic carbide C.

  Therefore, the present invention provides a pyrolytic carbide discharge cooling system that has a simple structure, can be reduced in weight, and can effectively use energy.

The pyrolytic carbide discharge cooling system according to the present invention employs the following means in order to solve the above problems.
The invention according to claim 1 includes a pyrolysis furnace that pyrolyzes waste in a reducing atmosphere to generate pyrolysis gas and pyrolysis carbide, and burns the pyrolysis gas discharged from the pyrolysis furnace to generate a high temperature. A hot air generating furnace for generating gas, a hot air passage for supplying a high-temperature gas generated in the hot air generating furnace as a heat source of the pyrolysis furnace, a screw conveyor for conveying the pyrolytic carbide discharged from the pyrolysis furnace, A hood installed near the screw conveyor to form a flow of cooling air around the screw conveyor, a fan installed outside the hood and sucking air in the hood, and sucked by the fan And an air supply passage for supplying the heated air as combustion air to the hot-air generating furnace.

  The invention according to claim 2 is the invention according to claim 1, wherein the screw shaft of the screw conveyor has a hollow cylindrical shape penetrating in the axial direction, and the air sucked by the fan is inside the screw shaft. It is characterized by being able to distribute.

  The invention according to claim 3 is characterized in that, in the invention according to claim 1 or 2, an impact device for applying vibration to the trough of the screw conveyor is provided outside the screw conveyor.

According to the first aspect of the present invention, the pyrolytic carbide can be cooled through the trough by flowing air outside the trough of the screw conveyor, and the trough does not have to have a double pipe structure. It can be simple and lightweight. Further, since it is air-cooled, the sealing performance with respect to the outside is low, and the seal structure becomes extremely simple as compared with the case of water-cooling.
In addition, the air preheated by heat exchange with the pyrolytic carbide through the trough is used as combustion air when burning the pyrolysis gas in the hot air generating furnace, so that the high temperature gas generated in the hot air generating furnace The temperature can be further increased. As a result, higher thermal energy can be supplied to the pyrolysis furnace, and the pyrolysis capability of the pyrolysis furnace is improved. In addition, the energy reuse rate is improved.

  According to the invention which concerns on Claim 2, since cooling air flows also into the inside of the screw shaft of a screw conveyor, the cooling capability with respect to a pyrolysis carbide | carbonized_material further improves.

  According to the invention according to claim 3, since the trough of the screw conveyor is not a double pipe structure, vibration can be applied to the trough from the outside of the screw conveyor by the operation of the impact device, and it exists between the trough and the screw flight. It is possible to facilitate the movement of the pyrolytic carbide. As a result, the contact surface with the trough in the pyrolytic carbide, that is, the heat transfer surface can be updated, and the cooling efficiency for the pyrolytic carbide is improved.

It is a block diagram in the Example of the pyrolysis carbide | carbonized_material discharge | emission cooling system which concerns on this invention. (A) is a principal part block diagram of the conventional pyrolytic carbide discharge | emission cooling system, (b) is XX sectional drawing of Fig.2 (a).

An embodiment of a pyrolytic carbide discharge cooling system according to the present invention will be described below with reference to the drawing of FIG.
As shown in FIG. 1, a pyrolysis carbide discharge cooling system 1 includes a pyrolysis furnace 2 that pyrolyzes waste such as municipal waste in a reducing atmosphere to generate pyrolysis gas and pyrolysis carbide, and a pyrolysis furnace. Installed in the vicinity of the screw conveyor 4, a hot air generating furnace 3 that combusts the pyrolysis gas discharged from 2 to generate a high-temperature gas, a screw conveyor 4 that conveys the pyrolysis carbide discharged from the pyrolysis furnace 2, and A hood 5, a fan 6 that is installed outside the hood 5 and sucks air in the hood 5, and an air supply path 7 (7 a, 7 a, 7 a, 7b), a fan 8 for sucking the pyrolysis gas discharged from the pyrolysis furnace 2, and a fuel gas supply path 9 (9a) for supplying the pyrolysis gas sucked by the fan 8 to the hot air generating furnace 3 as a fuel gas. , 9 ) And, it includes a Neppuro 10 for supplying hot gas generated in a hot air generating furnace 3 as a heat source to the thermal decomposition furnace 2, as main components.

  The pyrolysis furnace 2 includes a cylindrical furnace body 11 that rotates about the axis center, and a separation chamber 12 connected to the outlet side of the furnace body 11. The furnace body 11 is installed in a posture in which the shaft center S is slightly inclined with respect to the horizontal line so that the waste input side is upward and the outlet side, which is a connection side with the separation chamber 12, is downward. Further, a hot gas inlet 13 is provided on the outlet side of the furnace body 11, a hot gas outlet 14 is provided on the inlet side of the furnace body 11, and the hot gas inlet 13 and the hot gas outlet are provided in the furnace body 11. A hot gas passage (not shown) connected to 14 is provided.

  The hot gas as a heat source generated in the hot air generating furnace 3 flows into the hot gas passage in the furnace body 11 from the hot gas inlet 13 of the furnace body 11 through the hot air passage 10, and passes through the hot gas passage. It is discharged out of the furnace body 11 through the hot gas outlet 14. In addition, although illustration is abbreviate | omitted, since the exhaust heat gas discharged | emitted from the hot gas outlet 14 of the furnace main body 11 is still hot enough, it is supplied to another apparatus which is not shown in figure as a heat source, and uses exhaust heat.

  In the furnace main body 11, the input waste is indirectly heated to, for example, 350 to 550 ° C. by the high-temperature gas flowing through the high-temperature gas passage in a reducing atmosphere close to oxygen-free, whereby the waste is thermally decomposed. As a result, combustible pyrolysis gas G and solid pyrolysis carbide C are discharged into the separation chamber 12. More specifically, the waste is moved to the outlet side by its own weight while being agitated by the low-speed rotation of the furnace body 11 installed in a downward inclined posture toward the outlet side, and is thermally decomposed during that time. Pyrolytic carbide C and pyrolysis gas G are generated. The pyrolytic carbide C also moves to the outlet side by its own weight due to the rotation of the furnace body 11 and is discharged from the furnace body 11 to the separation chamber 12. On the other hand, the pyrolysis gas G is discharged from the furnace body 11 to the separation chamber 12 by being sucked into the separation chamber 12 by the fan 8 connected to the gas outlet 15 provided at the top of the separation chamber 12.

In the separation chamber 12, the pyrolysis gas G and the pyrolysis carbide C are separated. The pyrolysis gas G separated in the separation chamber 12 is sucked by the fan 8 from the gas outlet 15 of the separation chamber 12 through the fuel gas supply path 9a, and further supplied to the hot air generating furnace 3 through the fuel gas supply path 9b. Supplied as a gas.
The hopper portion 16 provided at the lower portion of the separation chamber 12 is connected to a charging port 18 provided in the trough 17 of the screw conveyor 4, and the pyrolytic carbide C separated in the separation chamber 12 is separated from the hopper portion 16. It is put into the trough 17 of the screw conveyor 4.

  The screw conveyor 4 includes a tubular trough 17 and a screw 19 that rotates about the axis within the trough 17. The screw shaft 20 of the screw 19 is rotatably supported by the trough 17 at both axial ends thereof via bearings (not shown). The screw shaft 20 has a hollow cylindrical shape penetrating in the axial direction, and both end openings communicate with the outside of the trough 17. A slight clearance is provided between the outer peripheral surface of the screw flight 21 spirally provided on the outer periphery of the screw shaft 20 and the inner peripheral surface of the trough 17 in order to prevent biting of foreign matter. A discharge tube 22 for discharging the pyrolytic carbide C extends downward on the trough 17 on the opposite side of the input port 18 in the axial direction. Note that the tip of the discharge cylinder 22 is configured to be opened and closed by a flap (not shown), and when the flap is closed, air is prevented from flowing into the trough 17 from the outside. Only the pyrolytic carbide C is discharged from the trough 17.

  Further, a plurality of striking devices 23 that strike the trough 17 and vibrate the trough 17 are provided outside the trough 17 at predetermined intervals in the axial direction. The striking device 23 vibrates the trough 17, and thereby shakes the pyrolytic carbide C staying between the outer peripheral surface of the screw flight 21 and the inner peripheral surface of the trough 17 to facilitate the movement. By operating this striking device 23, it is possible to prevent the pyrolytic carbide C from staying between the outer peripheral surface of the screw flight 21 and the inner peripheral surface of the trough 17. The striking device 23 may be a pneumatically driven so-called air knocker, but there is no limitation on its structure, driving source, etc. as long as the above object can be achieved, and it may be an electromagnetically driven type.

  The hood 5 is provided separately from the screw conveyor 4 and is installed so as to surround the periphery of the screw conveyor 4. More specifically, the hood 5 has a cylindrical shape in which one end side in the axial direction is greatly opened and the other end side is closed, the opening 24 is arranged on the discharge cylinder 22 side of the screw conveyor 4, and the closed end portion 25 is arranged on the screw conveyor. 4 is disposed and installed on the side of the inlet 18. Inside the hood 5 are housed a trough 17 of the screw conveyor 4, both ends of the screw shaft 20 exposed from the trough 17, a striking device 23, an inlet 18, and a discharge cylinder 22. A sufficiently large space is formed between the inner surface and the cooling air passage 26 through which the cooling air can flow. Note that the inlet 18 and the discharge cylinder 22 are installed through the side wall of the hood 5, and cooling air does not flow into the input port 18 and the discharge cylinder 22.

  The closed end 25 of the hood 5 is provided with a suction port 27. The air in the hood 5, that is, the cooling air passage 26 is sucked by the fan 6 from the suction port 27 through the air supply path 7 a and is further supplied as combustion air to the hot air generating furnace 3 through the air supply path 7 b. The

  Here, when the air in the hood 5 is sucked by the fan 6, the outside air is sucked into the hood 5 from the opening 24 of the hood 5, and the sucked air flows to the suction port 27. As a result, as indicated by broken line arrows in FIG. 1, an air flow is generated in the hood 5, that is, in the cooling air passage 26, and this air is the cooling air A that cools the pyrolytic carbide C conveyed by the screw conveyor 4. Function as. That is, the cooling air A flowing through the cooling air passage 26 and the pyrolytic carbide C moving in the screw conveyor 4 exchange heat through the troughs 17 of the screw conveyor 4.

  When the air in the hood 5 is sucked by the fan 6, the outside air is sucked into the screw shaft 20 from the end opening on the discharge tube 22 side of the screw shaft 20 of the screw conveyor 4, and the sucked air is sucked into the screw shaft 20. , Is discharged from the end opening on the input port 18 side to the closed end portion 25 side in the hood 5 and flows to the suction port 27. The air flowing in the screw shaft 20 also functions as cooling air A for cooling the pyrolytic carbide C conveyed by the screw conveyor 4. That is, the cooling air A flowing in the screw shaft 20 and the pyrolytic carbide C moving in the screw conveyor 4 exchange heat through the screw shaft 20.

  Thereby, the pyrolytic carbide C can be cooled to a predetermined temperature while being conveyed by the screw conveyor 4. In this embodiment, the cooling efficiency is improved by reversing the conveying direction of the pyrolyzed carbide C by the screw conveyor 4 and the flow direction of the cooling air A flowing in the cooling air passage 26 and the screw shaft 20 so as to counter flow. It is increasing.

The air sucked by the fan 6 from the suction port 27 of the hood 5 is air heated by heat exchange with the pyrolytic carbide C, and this warmed air, that is, preheated air, is supplied to the hot air generating furnace 3. Will be supplied.
In the hot air generating furnace 3, the pyrolysis gas as the fuel gas supplied from the separation chamber 12 is burned together with the preheated combustion air supplied from the hood 5, and high-temperature gas is generated. This hot gas is supplied to the pyrolysis furnace 2 through the hot air passage 10 as a heat source for thermally decomposing waste as described above.

  As described above, in this pyrolytic carbide discharge cooling system 1, the cooling air flows inside the cooling air passage 26 and the screw shaft 20 formed between the hood 5 and the screw conveyor 4, and is conveyed by the screw conveyor 4. The pyrolytic carbide C therein can be cooled to a predetermined temperature. In addition, the cooling capacity with respect to the pyrolytic carbide C can be appropriately set by changing the transport amount, the transport speed, the flow rate of cooling air, the flow velocity, and the like of the pyrolytic carbide C.

  Further, when the pyrolytic carbide C stays between the outer peripheral surface of the screw flight 21 of the screw conveyor 4 and the inner peripheral surface of the trough 17, the striking device 23 is operated to vibrate the trough 17, thereby The staying pyrolytic carbide C can be rocked and moved. Alternatively, the hammering device 23 is always operated in an appropriate cycle to vibrate the trough 17, so that the pyrolytic carbide C existing between the outer peripheral surface of the screw flight 21 and the inner peripheral surface of the trough 17 is rocked and moved. Therefore, it is possible to prevent the pyrolytic carbide C from staying between the outer peripheral surface of the screw flight 21 and the inner peripheral surface of the trough 17. Thereby, the contact surface with the trough 17 in the pyrolytic carbide C, that is, the heat transfer surface can be renewed, and the cooling efficiency for the pyrolytic carbide C can be improved.

The trough 17 of the screw conveyor 4 can be vibrated by the striking device 23 in this way because the cooling system is air-cooled and the trough 17 is not required to have a double tube structure.
Moreover, since it is not necessary to make the trough 17 into a double tube structure, the structure of the screw conveyor 4 is simplified and the weight can be reduced.
Further, since the cooling system is air-cooled, the sealing performance with respect to the outside is lower than that of the conventional water-cooled cooling system, and the seal structure is extremely simple as compared with the case of the water-cooled type.
As a result, the structure of the pyrolytic carbide discharge cooling system 1 is simplified, and the weight can be reduced.

  Further, as described above, the air preheated by cooling the pyrolytic carbide C is supplied to the hot air generating furnace 3 as combustion air, so that the temperature of the high temperature gas generated in the hot air generating furnace 3 is increased. And higher thermal energy can be supplied to the pyrolysis furnace 2. As a result, the thermal decomposition capability of the thermal decomposition furnace 2 can be increased. In addition, the energy reuse rate is improved.

  In addition, you may comprise so that the waste heat gas discharged | emitted from the hot gas outlet 14 of the pyrolysis furnace 2 and the air which distribute | circulates the air supply path 7b may be heat-exchanged indirectly. In this way, the heat energy of the exhaust heat gas can be recovered and the temperature of the air flowing through the air supply path 7b can be increased, so that the temperature of the combustion air supplied to the hot air generating furnace 3 is further increased. be able to. As a result, the temperature of the high-temperature gas generated in the hot-air generating furnace 3 can be further increased, and higher thermal energy can be supplied to the pyrolysis furnace 2, so that the thermal decomposition capability of the pyrolysis furnace 2 is further increased. be able to.

  In addition, in order to improve the cooling capability with respect to the pyrolysis carbide | carbonized_material C via the trough 17 of the screw conveyor 4, it is preferable to arrange | position many cooling fins on the outer peripheral surface of the trough 17. FIG. The filling rate of pyrolytic carbide C in the trough 17 is often 50% or less, and the lower half of the trough 17 is the main contact surface. It is particularly effective to dispose many cooling fins on the surface.

[Other Examples]
The present invention is not limited to the embodiment described above.
The shape of the hood 5 installed around the screw conveyor 4 is not limited to that of the embodiment. For example, the screw conveyor 4 can be accommodated in a small room, the small room can be used as a hood, and the inside of the small room can be configured as a passage for cooling air. Moreover, if the flow of cooling air can be formed around the screw conveyor 4 and a desired cooling capacity can be obtained, the screw conveyor 4 is not surrounded by the hood 5 but only a part of the screw conveyor 4. May be configured so as to be surrounded by a hood 5.

DESCRIPTION OF SYMBOLS 1 Pyrolysis carbide discharge cooling system 2 Pyrolysis furnace 3 Hot air generation furnace 4 Screw conveyor 5 Hood 6 Fan 7 Air supply path 10 Hot air path 17 Trough 20 Screw shaft 23 Blow device A Cooling air C Pyrolysis carbide G Pyrolysis gas

Claims (2)

A pyrolysis furnace for pyrolyzing waste in a reducing atmosphere to produce pyrolysis gas and pyrolysis carbide;
A hot air generator for burning the pyrolysis gas discharged from the pyrolysis furnace to generate a high-temperature gas;
A hot air passage for supplying hot gas generated in the hot air generating furnace as a heat source of the pyrolysis furnace;
A screw conveyor for conveying the pyrolytic carbide discharged from the pyrolysis furnace;
In order to form a flow of cooling air around the screw conveyor, it is installed in the vicinity of the screw conveyor, one end side in the axial direction of the screw conveyor is opened and the other end side is closed, and a suction port is provided at the closed end. and a hood that has been,
A fan installed outside the hood and sucking air in the hood from the suction port ;
An air supply path for supplying air sucked by the fan as combustion air to the hot air generating furnace ,
The screw shaft of the screw conveyor has a hollow cylindrical shape penetrating in the axial direction, and is configured so that air sucked by the fan can flow through the screw shaft. system. 2. The pyrolytic carbide discharge cooling system according to claim 1, further comprising an impact device that vibrates the trough of the screw conveyor outside the screw conveyor .

Images