JP2006028303A - Apparatus and method for gasifying polymer material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safe and inexpensive apparatus for pyrolyzing polymer materials, and a method for the same. <P>SOLUTION: This apparatus for pyrolyzing objects P to be treated mainly including polymer materials to gasify them in a furnace body 1 is equipped with a fuel nozzle 3 and an oxidant nozzle 4 for jetting and supplying a fuel and an oxidant, respectively into the furnace body 1, where the fuel nozzle 3 and the oxidant nozzle 4 are installed such that each forms a tubular flame swirling around the object to be treated by jetting the fuel and the oxidant, respectively towards the same direction in the circumference direction, in a tangential direction to the surrounding circle 5 surrounding the object P to be treated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus and a method for gasifying a polymer material by pyrolysis or partial oxidation.

  It is widely known to gasify waste containing a polymer material such as plastic and reuse this gas as fuel.

  Patent Document 1 discloses a power generation unit that generates power by pulverizing waste plastic with a pretreatment device, gasifying the pulverized plastic with a gasifier, and reusing the gas as fuel for a gas engine. .

This patent document 1 is provided with a coarse pulverizing device, a sorting device such as a wind force sorting / magnetic force sorting / eddy current sorting / vibrating screen sorting, and a fine pulverizing device in association with pulverization of waste plastic.
JP 10-47626 A

  In the apparatus of Patent Document 1, since waste plastic is pulverized prior to gasification, there is a risk that the plastic is heated by frictional heat during pulverization / crushing to generate gas or explode due to generation of static electricity. In order to prevent this danger, it is necessary to take measures such as providing a cooling mechanism or forming an inert gas atmosphere such as nitrogen gas in an actual machine.

  Also, the entire apparatus requires a coarse and fine pulverizer and various sorters in order to perform the above-mentioned pulverization.

  Therefore, in the apparatus of Patent Document 1, since the facilities are complicated and large, equipment costs and maintenance / management costs increase.

  Furthermore, when using the gasified gas, it is also necessary to increase the fuel concentration in the gas and to suppress fluctuations in this concentration.

  It is an object of the present invention to provide an apparatus and method that can eliminate the need for a pretreatment apparatus such as a pulverization / crushing apparatus that requires the above-described explosion prevention measures, and can gasify an object to be treated containing a polymer material such as plastic at low cost. And

  The present invention is an apparatus for gasifying an object to be processed mainly containing a polymer material in a furnace body, and has a fuel nozzle and an oxidizer nozzle for injecting and supplying fuel and an oxidant into the furnace body, respectively. The fuel nozzle and the oxidant nozzle are respectively tangential to the surrounding circle surrounding the workpiece in the furnace body and inject the fuel and the oxidant in the same swirling direction in the circumferential direction. It is provided to form a tubular flame that can be swung around an object.

In the present invention having such a configuration, the fuel and the oxidant injected from the fuel nozzle and the oxidant nozzle burn, respectively, and form a tubular flame on a circle tangent to the injection direction so as to surround the object to be processed. The polymer material to be treated is thermally decomposed or partially oxidized and gasified by radiation from the flame and heat transfer from the high temperature exhaust gas. For example, this gas is taken out from an exhaust gas pipe provided in the upper part of the furnace body.

  According to this invention, the object to be treated is surrounded by a tubular flame, and a flame is formed by the centrifugal force of the swirling flow so that unburned fuel gas exists in the outer peripheral portion of the tubular flame and burned gas exists in the central portion. As such, the oxidant reacts well with the fuel. Therefore, the oxygen concentration in the exhaust gas can be suppressed low, and when the oxygen concentration in the exhaust gas decreases, abnormal combustion downstream from the furnace is prevented, safety of the furnace is ensured, and repair costs are reduced.

  In the present invention, the furnace main body is provided with a gas injection nozzle at a position above the fuel nozzle and the oxidant nozzle, and the gas injection nozzle is substantially concentric with a diameter larger than the surrounding circle when viewed from above. In contrast, it is preferable that the fuel nozzle and the oxidizer nozzle be arranged so as to inject gas in the same tangential direction and circumferential direction. When a large swirl flow is generated by the gas injected in the tangential direction of the large-diameter circle from the gas injection nozzle, the unburned fuel gas and the residual oxidant having a high density due to the centrifugal force have a radius toward the inner peripheral wall side of the furnace body. As a result of flowing outward and descending along the inner peripheral wall, a secondary flow that descends on the outside of the circular swirling circle and the lower tubular flame and rises on the inside is generated. By this secondary flow, circulation of unburned fuel gas and residual oxidant and circulation of supplying heat downward are performed, and a tubular flame is stably formed. Thereby, even if the shape of the workpiece changes with the progress of gasification, the flame form is maintained, and the flow of the flame in the furnace body and its combustion are stabilized.

  Furthermore, in the present invention, the gas injection nozzle is connected to at least one of a preheating device that takes in air from outside and preheats and an exhaust gas line to the outside of the furnace, and injects at least one of preheated air and a part of the exhaust gas. It is preferable to do so.

  By doing so, the large swirl flow formed above can be heated to high temperature by the heat of the preheated air or exhaust gas. When the temperature of the large swirl flow is high, the viscosity in the flow increases, the apparent flow rate increases, and a strong swirl flow can be formed.

  In the present invention, the fuel nozzle for forming the tubular flame and the oxidizer nozzle are formed separately, and the respective injection ports may be arranged at different positions. It can also be arranged so that it merges in the vicinity. However, it is better to avoid joining the upstream side of the injection port, that is, premixing the fuel and the oxidant, because it causes backfire and the like.

  Furthermore, in the present invention, it is preferable that the fuel nozzle and the oxidizer nozzle each have a vertically narrow slit port. By carrying out like this, a flame extends in the up-down direction, it becomes a stable tubular flame, and can fully surround a to-be-processed object in the same direction.

  In the present invention, as described above, the fuel and the oxidant injected from the fuel nozzle and the oxidant nozzle, respectively, burn and form a tube on a circle whose tangent is the injection direction, and include a polymer material. The gas to be treated containing the above polymer material is gasified by the radiation from this flame and the heat transfer from the high temperature exhaust gas. Since gasification is performed by both heat transfer, the heat efficiency is good and the operation cost is low. When the oxygen concentration in the exhaust gas decreases, abnormal combustion downstream from the furnace is prevented, safety is ensured, and repair costs are reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  In FIG. 1, the code | symbol 1 is the furnace main body of the gasifier in this embodiment, and it is made from a heat resistant material and has a pressure | voltage resistant structure. The furnace body 1 has a vertically long cylindrical body as a whole, and the upper and lower walls have tapered peripheral walls to ensure the strength thereof.

  An arrangement base 2 having high heat resistance and high strength is provided at the bottom of the furnace body 1, and the workpiece P can be arranged on the arrangement base 2. Although not shown, the furnace main body 1 is provided with a double on-off valve that can be freely opened and closed for carrying in the workpiece P. Here, the object to be treated P is mainly a synthetic polymer material such as plastic or natural polymer material such as paper, cloth, wood, firewood, etc. It is carried in. However, an excessively large thing may be cut | disconnected by the magnitude | size which is mounted on the said arrangement | positioning stand 2.

  A fuel nozzle 3 and an oxidizer nozzle 4 are attached to the furnace body 1. These nozzles 3 and 4 are formed as slits in the vertical direction so as to be understood from FIGS. 1 and 2 and are opened inside the furnace main body 1, and as shown in FIG. The fuel and the oxidant are disposed so as to be directed tangential to a virtual surrounding circle 5 surrounding the workpiece P. These nozzles 3 and 4 are located at the same position in the height direction, and preferably extend to a height range that covers the maximum expected height of the workpiece P as seen in FIG. The fuel nozzle 3 is connected to, for example, a gas fuel supply source (not shown), and the oxidant nozzle 4 is connected to an air supply source (not shown) as an oxidant.

  In the present embodiment, two gas injection nozzles 6 are connected to the furnace body 1 above the fuel nozzle 3 and the oxidant nozzle 4. As shown in FIG. 2, these gas injection nozzles 6 are arranged so that the injection gas faces the tangential direction with respect to the virtual circle 7 that is substantially concentric with the virtual encircling circle 5 and larger in diameter. ing. The direction of injection in the circumferential direction is also the same as in the case of the virtual surrounding circle 5.

  The furnace body 1 has an exhaust gas line 8 connected to a ceiling wall, and a heat exchange device 9, an exhaust gas treatment device 10, and a blower device 11 as a preheating device are sequentially connected to the exhaust gas line 8. 8 reaches the chimney 12 after passing through these devices. The exhaust gas treatment apparatus 10 has functions of secondary combustion, harmful gas removal, and dust removal. The heat exchange device 9 is provided so that the outside air taken in by the blower 13 is preheated to a high temperature by exchanging heat with the exhaust gas in the exhaust gas line 8 in the air supply line 14. The latter air is connected so as to reach the two gas injection nozzles 6. A return line 15 for returning the treated exhaust gas extends from the downstream side of the blower device 11 and is selectively connected to the air supply line 14 reaching the gas injection nozzle 6. The number of fuel nozzles 3 and oxidant nozzles 4 is not limited to one, and a plurality of nozzles may be provided. The number of gas injection nozzles 6 is not limited to two, and a plurality of gas injection nozzles 6 may be provided.

  In the present embodiment as described above, the workpiece P containing the polymer material is gasified in the following manner.

(1) First, the workpiece P is carried in from the double on-off valve while suppressing the intake of outside air and placed on the arrangement table 2, and the on-off valve is closed.

(2) Next, fuel is injected from the fuel nozzle 3 and air is injected from the oxidizer nozzle 4 into the furnace body 1. At the same time, at least one of preheated air sent via the air supply line 14 and part of the exhaust gas from the return line 15 is injected into the furnace main body 1 from the gas injection nozzle 6 located above. Since the fuel nozzle 3 and the oxidant nozzle 4 have slit-like injection ports, the fuel burns and the tubular flame 16 forms a swirling flow around the workpiece as shown in FIG. Further, the preheated air or exhaust gas injected from the gas injection nozzle 6 is the tubular flame 1.
A large swirling flow 17 having a diameter larger than 6 is formed, and a secondary flow 18 is generated between the tubular flame 16 and the large swirling flow 17 as shown in FIG. By this secondary flow 18, circulation of unburned fuel gas and residual oxidant and thermal circulation for supplying heat downward are performed, and the tubular flame 16 is stabilized. By the radiation from the tubular flame 16 and the heat transfer from the high temperature exhaust gas, the workpiece P is heated and thermally decomposed or partially oxidized to be gasified.

(3) The gasified gas is discharged through the exhaust gas line 8, and after heat exchange with the air in the air supply line 14 is performed by the heat exchange device 9, it cools itself and is made harmless by the exhaust gas treatment device 10. The

(4) The detoxified exhaust gas is discharged from the chimney 12 to the atmosphere or taken out by an apparatus as appropriate for reuse as fuel gas. A part of the exhaust gas is selectively sent to the gas injection nozzle 6 through a feedback line 15.

  In this embodiment, the fuel nozzle and the oxidizer nozzle are formed separately, and their injection ports are provided in the furnace body at different positions, but these injection ports are provided close to each other and the injection flows are immediately formed. You may make it join. It is better to avoid merging upstream of the injection port, that is, premixing the fuel and the oxidant, because it may cause flashback and the like.

  In the present embodiment, the workpiece P is disposed on the placement table 2 at the bottom of the furnace body 1 and the tubular flame 16 is formed so as to surround the workpiece P. However, the workpiece P is placed on the furnace body 1. Even if the workpiece P is placed at random and is biased with respect to the center of the furnace body 1, the tubular flame 16 is formed so as to surround the workpiece P, so that the same effect can be obtained. , Stable gasification.

  Further, the fuel nozzle 3 and the oxidizer nozzle 4 may be provided at a position above the workpiece P without being provided at a height position corresponding to the height position of the workpiece P, and the gas injection nozzle 6 may be provided further upward. The material P can be stably gasified by heating by radiation or by heat circulation by the secondary flow 18, and abnormal combustion downstream from the furnace can be prevented.

  Further, even if the fuel nozzle 3 and the oxidizer nozzle 4 are provided so as to form a tubular flame in the exhaust gas duct near the furnace body outlet, the residual oxygen is consumed by the tubular flame and the oxygen concentration in the exhaust gas can be suppressed low. , Downstream abnormal combustion can be prevented. Instead of heating with a tubular flame, the exhaust gas in the exhaust gas duct can be heated with an electric heater or the like to similarly prevent abnormal combustion on the downstream side.

It is a schematic block diagram of the apparatus of one Embodiment of this invention. It is the cross-sectional view seen from the upper part about the furnace main body of the apparatus of FIG. It is a figure which shows the flow in a furnace main body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Furnace body 2 Arrangement | positioning stand 3 Fuel nozzle 4 Oxidant nozzle 5 Surrounding circle 6 Gas injection nozzle 7 Large swirl flow 8 Exhaust gas line 9 Preheating apparatus (heat exchange apparatus)

Claims (7)

  In an apparatus for gasifying an object to be processed mainly containing a polymer material in a furnace body, the fuel nozzle includes a fuel nozzle and an oxidant nozzle for injecting and supplying fuel and an oxidant into the furnace body. And an oxidizer nozzle inject the fuel and the oxidizer in the same swirl direction in the circumferential direction and tangential to the encircling circle surrounding the workpiece in the furnace body, and around the workpiece. A polymer material gasifier characterized by being provided to form a swirling tubular flame.   The furnace body is provided with a gas injection nozzle at a position above the fuel nozzle and the oxidizer nozzle, and the gas injection nozzle is tangential to a substantially concentric circle having a larger diameter than the surrounding circle when viewed from above. The polymer material gasifier according to claim 1, wherein the gas is injected in the circumferential direction so as to inject the gas in the same turning direction as the fuel nozzle and the oxidizer nozzle.   The gas injection nozzle is connected to at least one of a preheating device that takes in air from the outside and preheats and an exhaust gas line to the outside of the furnace, and injects at least one of the preheated air and a part of the exhaust gas. The polymer material gasifier according to claim 2.   The polymer material gasification apparatus according to claim 1 or 2, wherein the fuel nozzle and the oxidant nozzle are formed separately, and the respective injection ports are arranged at different positions.   3. The polymer material gasification according to claim 1 or 2, wherein the fuel nozzle and the oxidizer nozzle are formed separately, and are arranged so that the respective injection flows merge in the vicinity of the injection port. apparatus.   6. The polymer material gasifier according to claim 1, wherein each of the fuel nozzle and the oxidant nozzle has a vertically and vertically elongated slit port. In a method of gasifying an object to be processed mainly containing a polymer material, the object to be processed is disposed in a furnace body, and fuel and an oxidant are respectively injected into the furnace body from a fuel nozzle and an oxidant nozzle. A polymer material gasification method comprising forming a tubular flame swirling around a treatment object, pyrolyzing or partially oxidizing the object to be treated to gasify it, and taking out the generated gas outside the furnace body.

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