JP2005350329A - Continuous carbonating method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce activated carbon through a process for surely carrying out the extinguishment of a carbonized material in a method and an apparatus for continuously carbonizing wood chips. <P>SOLUTION: The carbonized material is obtained by repeating processes of moving a raw material M along a nearly fixed route from one side end of an inside cylinder 11 to the outside through an outside cylinder 12 in a rotary furnace having a double cylinder structure, igniting the raw material at another end side of the inside cylinder 11 during the movement and after continuing the combustion, stopping the supply of air to the space S between the inside cylinder and the outside cylinder to extinguish. The activated carbon is produced by carrying out an activating process on the carbonized material with the supply of water and the burning of the carbonized material is extinguished by gaseous nitrogen N<SB>2</SB>. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and an apparatus for carbonizing a raw material using a rotary furnace having a double cylinder structure.

  As a device capable of continuously performing the carbonization treatment of the combustible material, there is a device disclosed in Japanese Utility Model Laid-Open No. 50-101475, which has a rotating drum composed of an inner and outer double cylinder provided with a spiral blade on the inner surface. , With a burner facing one end of the inner cylinder, preheated to a predetermined temperature, dehydrated by heating at the front stage of the inner cylinder, calcined and charred at the rear stage, and gradually cooled while flowing backward in the outer cylinder It is possible to take out. However, in such an apparatus, since the inside of the outer cylinder is brought into contact with normal temperature air and gradually cooled while being sent by the spiral blade, it is affected by the heat of the inner cylinder in the combustion state. In order to lower the temperature to the desired temperature, a long cooling section is required.

  Therefore, the present applicant has developed a method and an apparatus capable of carbonizing a raw material with higher thermal efficiency even though only a smaller installation area is required (Japanese Patent Laid-Open No. 10-279949, Japanese Patent No. 3021387). ). The invention of the same number goes through a process of quenching and cooling the combustion in a space in which the supply of air between the inner cylinder and the outer cylinder is shut off, and a ventilation shut-off valve means for this purpose is provided in the outer cylinder. As a result, the supply of oxygen is cut off so that the fire is extinguished quickly, and a long cooling section like the above is not required. However, when the invention of the same issue is applied to wood chips, fire extinguishing is sufficient. It was pointed out that it was not.

In other words, waste wood generated when a wooden house is demolished, or thinned wood, driftwood, etc. are crushed and crushed into wood chips, which are fired and carbonized, for example, hitting branches and roots As for the portion, if the burned chip is in a habit, it may be discharged out of the machine without disappearing. The remaining soot will burn up when exposed to air after being discharged out of the machine, which will not only burn the mixed carbide, but is also dangerous. In addition, since it is rare that the disappearance occurs, but it is not known when it occurs, there is a problem that the ventilation is interrupted for a time longer than necessary, and the process time is prolonged.

Japanese Utility Model Sho 50-101475 JP-A-10-279949

  The present invention has been made paying attention to the above points, and the problem to be solved is that in the method and apparatus for continuously carbonizing wood chips, the carbide is surely extinguished and the activated carbon is passed through the extinguishing process. Is to manufacture.

  In order to solve the above problems, the present invention moves a raw material along a substantially constant path from one end side of an inner cylinder to the outside through an outer cylinder to a rotary furnace having a double cylinder structure. Carbide is obtained by continuously igniting the raw material at the other end of the cylinder and maintaining the combustion, and subsequently suppressing the combustion in the space where the air supply between the inner cylinder and the outer cylinder is shut off. In this case, by supplying water to the carbide, an activation process for the carbide is performed to produce activated carbon, and means for extinguishing the carbide with nitrogen gas is taken.

  The continuous carbonization method has a double cylinder structure composed of an inner cylinder and an outer cylinder, and can rotate around a cylinder axis, an introduction means for introducing a raw material into the rotary furnace, and a rotary furnace There is a derivation means for deriving the carbonized material, and the raw material introduced into one end side of the inner cylinder moves while burning by the combustor on the other end side of the inner cylinder and moves into the outer cylinder. The outlet means is provided with a valve means for shutting off the ventilation into the outer cylinder so as to suppress the fire in the cylinder, and includes a nozzle for spraying water and a nozzle for supplying nitrogen gas in the process of hermetically conveying the carbide. It is desirable to carry out by a continuous carbonization apparatus.

  The continuous carbonization method and the apparatus for implementing the same according to the present invention are for carbonizing a raw material supplied thereto using a rotary furnace having a double cylinder structure. The raw material is a so-called wood chip, and includes wood produced by pruning, driftwood, and any other wood, and these are supplied in a crushed and crushed form. Therefore, it includes those generated by sawdust and other wood processing.

  In this invention, an activation process is implemented by supplying water to a carbide | carbonized_material, a carbide | carbonized_material can be activated and an activated carbon can be manufactured by this process, and thorough fire extinguishing is also aimed at. In general production of activated carbon, a method is used in which organic matter is carbonized, the carbide is once taken out from the carbonization apparatus, placed in another activation furnace, heated, air is shut off, and steam is blown. For this reason, conventionally, two types of apparatuses, a carbonization furnace and an activation furnace, are required, and the process takes an extra portion of the carbide in and out, resulting in wasted time and cost. However, in the present invention, the activation step is carried out by spraying water on the carbide, generating heated steam, and treating with the heated steam, and at this time, activated carbon can be produced.

In the present invention, the carbide obtained by calcination of the above raw materials is extinguished in an inert gas atmosphere. While the carbide is being removed from the outer cylinder, it has been extinguished at a rate close to 100% during the movement in the outer cylinder where ventilation is blocked. The department may remain gone. Therefore, in the present invention, the carbide is passed through an inert gas atmosphere in order to extinguish the fire with the inert gas. Therefore, in the present invention, there is a significance in surely extinguishing gas by active fire extinguishing through the fire extinguishing process. Nitrogen gas, carbon dioxide, or the like can be used as the fire extinguishing gas, and cooling of the activated carbon can be promoted by supplying it at a low temperature.

  Since the present invention is configured and operates as described above, in the method and apparatus for continuously carbonizing the raw material made of wood chips, the fire is surely extinguished by passing the carbide through the nitrogen gas atmosphere, and the carbide is added to the carbide. By supplying water, activated carbon is produced by producing activated carbon, and fire extinguishing can be further completed.

In carrying out the continuous carbonization method according to the present invention, the raw material consisting of wood chips is moved along a substantially constant path that constitutes the rotary furnace, from the inner cylinder to the outer cylinder, and to the outside of the rotary furnace. The double cylinder structure of the inner cylinder and the outer cylinder is effectively used by supplying the raw material into the inner cylinder and shifting from there to the outer cylinder. That is, the raw material is combusted in the inner cylinder, and after the combustion product moves to the outer cylinder, the supply of air between the inner cylinder and the outer cylinder is shut off, and the combustion of the combustion substance is extinguished in the outer cylinder, Carbide is produced. The carbide is gradually cooled while moving in the outer cylinder.

  A rotary furnace having a double cylinder structure uses a furnace that can move a raw material and its combustion products (carbides) in the axial direction of the cylinder by rotation. As such a rotary furnace, for example, a structure in which a blade-like member is provided in a spiral shape on the inner surfaces of a cylindrical inner cylinder and an outer cylinder, and the rotational force of the furnace is a propulsive force for a raw material or the like can be used. A method in which a combustion flame directly acts on the raw material is optimal from the viewpoint of thermal efficiency, and the raw material is sufficiently dried by residual heat until it is exposed to the combustion flame. In this way, the raw material made of wood chips moves through the inner cylinder from one end to the other while burning, and moves to the outer cylinder. The supply of air is cut off between the inner cylinder and the outer cylinder, so that combustion gradually goes to fire suppression.

  The carbide thus put into a fire extinguishing state enters a process of actively extinguishing with nitrogen gas. Moreover, water is injected to the charcoal extinguished by the passage of the nitrogen gas atmosphere, thereby carrying out an activation process by heating steam treatment. At the same time, thorough fire extinguishing will be eradicated to eliminate the possibility of non-extinguishing. By going through the activation process, the carbide from the wood chip is changed to activated carbon. Either the step of jetting water or the step of supplying nitrogen gas may be performed first or may be performed in parallel.

  As shown in the examples, the fire extinguishing step and the activation step are a method of performing the carbide on the inside of the rotating cylinder, and a method of performing the method by providing a sealed space such as a screw conveyor outside the rotating cylinder. Can be implemented in two ways. The supply of air to the outer cylinder is interrupted, and it is easy to supply water to the internal space, further supply a gas such as nitrogen, and control the supply.

  Such a continuous carbonization method can be implemented by the continuous carbonization apparatus shown in FIG. The rotary furnace 10 that combusts the raw material has a double cylinder structure including an inner cylinder 11 and an outer cylinder 12. One end of the inner cylinder 11 is a portion for introducing a raw material, and an introduction means 15 including a hopper 13 for that purpose, a feeder 14 for feeding the raw material into the inner cylinder, and the like are provided. As the feeder 14, a screw conveyor type quantitative feeder can be used. The rotary furnace 10 can be supported by the support roller 17 on the base 16 in a substantially horizontal state, and can rotate around the axis of the cylindrical shaft in that state. Reference numeral 18 denotes an outer ring supported by the roller 17. In the illustrated rotary furnace 10, the inner cylinder 11 is formed longer than the outer cylinder 12 on the introduction side, an end outer casing 19 is provided at the inner cylinder end, and an intermediate outer casing 21 is provided at the end of the shorter outer cylinder 12. Is provided.

  A combustor 20 is provided at the other end of the rotary furnace 10 toward the other end opening of the inner cylinder 11. In the illustrated example, the ends of the inner cylinder 11 and the outer cylinder 12 are located in the head outer casing 22, and the combustor 20 is attached to the head outer casing 22 at the axial center position. See FIG. 1, FIG. The outer casings 19, 21, and 22 surrounding the ends of the inner cylinder 11 and the outer cylinder 12 also serve as a seal for keeping the inside of the rotating cylinder in a sealed state. The inner cylinder 11 and the outer cylinder 12 constituting the rotary furnace 10 are formed so as to be integrally rotatable, and are driven on a power transmission annular portion 23 such as a chain ring and a driving means 24 such as a motor provided on the outer periphery of the outer cylinder 12. The shaft can be coupled and rotated by transmission means 25 such as a chain. See FIG. 2 and FIG.

  The inner cylinder 11 constituting the rotary furnace 10 has a large number of blades 26 on the inner side for moving the raw material charged from the introduction means 15 in the substantially axial direction. The blades 26 have a shape, a structure, or an arrangement that is inclined in a direction to change the circumferential movement force received by the inner circumferential surface thereof by the rotation of the inner cylinder 11 into the axial movement force. For example, as shown in detail in FIGS. 3 to 5, the inclination of the introduction-side blades 26 is stronger than the others, and the height of the blades 26 can be made higher to change the speed and propulsive force. In order to transfer the raw material from the inner cylinder 11 to the outer cylinder, a window-like or other passage portion 27 is provided at the tip of the inner cylinder 11. In order to move the raw material transferred to the outer cylinder 12 in the reverse direction, the raw material is conveyed by the blades 28 inclined in the reverse direction. The blades 28 can be provided on the inner surface of the outer cylinder 12. See FIGS. In the case of the illustrated inclination, it is a configuration in which the raw material is advanced when the right rotation is seen from the tip.

  The combustor 20 is provided at the other end of the rotary furnace 10. The flame of the combustor 20 at a position slightly lower than the axial center facilitates ignition and combustion of the raw material. Reference numeral 29 denotes an inspection window. An exhaust part 30 is provided for discharging gas generated by combustion in the inner cylinder 11. This surrounds the end outer casing 19 and communicates with the inner space of the inner cylinder 11 at one end through a passage 31 to release the gas from the chimney 32 at the end. See FIG.

  Means for blocking the ventilation to the space S surrounded by the outer cylinder 12 and the inner cylinder 11 is provided at an appropriate position of the lead-out means 37 for the purpose of charcoal fire and cooling of the carbide by quenching of the burned raw material. In the illustrated case, a shooter 36 is provided at the lower part of the outer casing 21, and a derivation means 37 is provided following the shooter 36 for taking out carbides. See FIG. The lead-out means 37 includes a chute 42 provided with two-stage dampers 38 and 38 as means for blocking the ventilation to the space S inside the rotary furnace in order to take out carbides. By keeping one side closed, the carbide can be continuously taken out. Reference numeral 39 denotes a screw conveyor.

  An activation part 40 for performing the activation process on the carbide is provided in the front stage of the derivation means 37 (see FIGS. 5 and 9). The activation part 40 is set in a space part surrounded by the outer cylinder 12 and the inner cylinder 11, and a nozzle 41 for spraying water on the carbide for activation is installed in the shooter 36 part.

  The fire extinguishing unit 43 is provided in association with the screw conveyor 39, and specifically includes a plurality of nozzles 44 for injecting nitrogen gas onto the conveyed carbide. The fire extinguishing unit 43 can drive the screw conveyor at a speed suitable for the amount of carbide supplied from the damper 38, and can increase the certainty of fire extinguishing due to the balance between the speed and the amount of nitrogen gas. The fire extinguishing unit 43 has a water cooling jacket 45 surrounding the outside of the screw conveyor 39, and can perform final cooling.

<Supply of raw materials>
When the continuous carbonization method according to the present invention is carried out using an apparatus as exemplified above, the raw material M is supplied from the introducing means 15 to one end of the inner cylinder. Prior to the introduction of the raw material, the combustor 20 is operated to heat the inside of the furnace, and the temperature rise is confirmed by a sensor or the like. When the rotary furnace 10 is rotated, the raw material can be moved substantially in the axial direction. The inner cylinder 11 has a low temperature on one end side and a high temperature on the tip side where the combustor 20 is disposed. Increases the dryness while being heated by the combustion gas flow N as it advances.

<Combustion of raw materials>
The raw material is heated as it advances in the inner cylinder 11 and is in a combustion state, and when it further advances, it is directly exposed to the combustion flame and burns. When this is schematically shown in FIG. 9, the one end portion 47 of the inner cylinder 11 is a drying process, the intermediate portion 48 is a combustion / drying process, and the tip end side 49 is a combustion process exposed to a combustion flame. Therefore, the raw material burns at the optimum temperature set by a temperature sensor or the like, and continuously moves from the passage portion 27 at the tip of the inner cylinder into the outer cylinder 12. Combustion that has moved to the space S in the outer cylinder 12 continues to burn in a natural state.

<Carbonization>
The space S of the outer cylinder 12 is in a state where the air supply is cut off by closing the shutoff valve means 35. The temperature of the carbide is about 800 ° C. For this reason, the combustion product M ′ gradually extinguishes and carbonizes, and moves in the space S in the opposite direction to the raw material. In the meantime, the carbide is activated by the steam generated by heating the water sprayed from the nozzle 41, cooled, and discharged from the outlet means 37 as activated carbon.

  As an example of obtaining carbide, the inner cylinder 11, that is, the combustion chamber temperature rises to approximately 300 ° C to 450 ° C. Even when the apparatus according to the present invention is used, when the temperature setting is lowered, the apparatus does not carbonize, but for example damp sawdust is dried.

<Fire extinguishing>
The carbide conveyed by the derivation means 37 enters the fire extinguishing unit 43, and nitrogen gas N ₂ is supplied from the nozzle 44 at a low temperature (about 5 ° C.) in the fire extinguishing unit 43 to fill the inside of the screw conveyor 39 which is a sealed space. Therefore, even if the carbide to be transported is part of the branches, roots, etc., even if soot remains, it will be actively extinguished while moving the fire extinguishing part 43, and the whole is also cooled by the water cooling jacket 45. The temperature of the carbide cooled and discharged from the dampers 38 and 38 is lowered to about 30 to 40 ° C. The carbide thus produced can be used as activated carbon having a specific surface area of about 300 to 1000 m ² / g from the nozzle 41. Nitrogen gas N ₂ extinguishes the carbide in the space inside the outer cylinder, and further reverses toward the exhaust part 30.

The top view which shows Example 1 of embodiment of the apparatus directly used for implementation of the continuous carbonization method which concerns on this invention. The front view of the thing of FIG. III-III sectional view taken on the line of FIG. IV-IV sectional view taken on the line of FIG. VV sectional view taken on the line of FIG. FIG. 6 is a sectional view taken along line VI-VI in FIG. 2. The left view of FIG. The right view of FIG. The schematic of the method which concerns on this invention, or explanatory drawing which shows an apparatus operating state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Rotating furnace 11 Inner cylinder 12 Outer cylinder 15 Introduction means 19, 21, 22 Outer casing 20 Combustor 26, 28 Blade 30 Exhaust part 36 Shooter 37 Derivation means 38 Damper as shut-off valve means 39 Screw conveyor 40 Activation parts 41, 44 Nozzle 43 Fire extinguishing part

Claims (2)

The raw material is moved along a substantially constant path from one end side of the inner cylinder to the outside through the outer cylinder to the rotary furnace having a double cylinder structure, and the raw material is ignited on the other end side of the inner cylinder in the meantime. In addition, the combustion is continued, and then the process of quenching the combustion in the space where the air supply between the inner cylinder and the outer cylinder is cut off is continuously performed to obtain carbide, and water is supplied to the carbide. The continuous carbonization method characterized by carrying out the activation process with respect to the carbide to produce activated carbon and extinguishing the carbide with nitrogen gas. A rotary furnace having a double cylinder structure consisting of an inner cylinder and an outer cylinder, which can rotate around the cylinder axis, introduction means for introducing the raw material into the rotary furnace, and derivation for deriving carbonized material in the rotary furnace The raw material introduced into one end side of the inner cylinder is moved while being combusted by the combustor on the other end side of the inner cylinder, moved into the outer cylinder, and further extinguished in the outer cylinder. The derivation means is provided with valve means for shutting off the ventilation into the outer cylinder, and has a nozzle for injecting water and a nozzle for supplying nitrogen gas in the process of sealingly transporting the carbide. Carbonization equipment.

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