JPH1192127A - Continuous heating furnace for producing carbon product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the furnace facilities for continuously producing carbon product contg. substantially no volatile carbonaceous components from an object to be heated, which contains volatile carbonaceous components. SOLUTION: The furnace facilities consist of: a former stage furnace 1 for heating an object to be heated to remove volatile carbonaceous components; a latter stage furnace 3 for further heating the heated object to a higher temp. to enhance the degree of carbonization of the object; and an intermediate chamber 2 interposed between the both furnaces 1 and 3. In the furnace facilities, each of the furnaces 1 and 3 is provided with a heating element(s) and also, doors are placed at the inlet of the former stage furnace 1 and the outlet of the latter stage furnace 3 and between the intermediate chamber 2 and each of the furnaces 1 and 3, respectively and further, the atmosphere of each of the furnaces 1 and 3 can be controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to continuously produce a carbon product having substantially no volatile carbonaceous component and having a desired degree of carbonization from a carbonaceous material containing a volatile carbonaceous component. The present invention relates to a continuous heating furnace.

[0002]

2. Description of the Related Art In the production of carbon electrodes and other carbon products, carbon materials containing almost no volatile components or pyrolytic components such as graphite and coke, coal tar, crude oil, naphtha cracked oil, etc. Kneaded with a viscous liquid containing a large amount of volatile carbonaceous components (= carbonaceous components that evaporate by heating), which is the distillation residue, and impregnated these viscous liquids into molded carbonaceous materials Heating is performed to remove volatile components and to carbonize the residue. The heating is usually performed at a relatively low temperature, for example, at 500 to 1000 ° C. to remove volatile components and carbonize, and at a high temperature, for example, at 1200 to 1500 ° C., to remove methane, carbon monoxide, and carbon dioxide from the residue. Removing carbon and the like to increase the degree of carbonization.
There may be a step of heating to 3000 ° C. to graphitize.

[0003]

The heating for producing carbon products is usually performed in a batch system, but in order to increase the productivity, a continuous system in which the objects to be heated sequentially move in a tunnel furnace. Is preferred. However, at the stage of heating at a relatively low temperature to remove volatile components and carbonize, a large amount of heavy gas is generated, so measures need to be taken. In this case, only light gas is mainly generated, and the amount of generated gas is small. Therefore, the two heating steps need to be operated under significantly different conditions. The present invention aims to provide a heating furnace that can cope with this.

[0004]

The heating furnace according to the present invention comprises:
A pre-stage furnace for heating the object to remove volatile carbonaceous components contained therein, and a post-stage furnace for heating the object to a higher temperature to improve the degree of carbonization, and an intermediate furnace interposed between the two. The object to be heated is charged from the inlet of the former furnace and discharged from the outlet of the latter furnace through the intermediate chamber, and both the former furnace and the latter furnace have a heating element inside. , Doors are installed at the inlet of the former furnace and the outlet of the latter furnace, and between the former furnace and the intermediate chamber and between the latter furnace and the intermediate chamber,
In addition, the atmosphere in the furnace can be controlled.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in further detail. The continuous heating furnace according to the present invention comprises at least three parts of a pre-stage furnace, a post-stage furnace, and an intermediate chamber interposed therebetween. . Doors are provided at the entrance of the former furnace and the exit of the latter furnace, respectively. Doors are also provided between the intermediate chamber and the first and second furnaces. Therefore, the intermediate chamber is separated from the first and second furnaces by a door, and the atmosphere of the first and second furnaces is shut off. If desired, the atmosphere of each furnace can be controlled independently. ing.

[0006] Each of the former furnace and the latter furnace has a heating element for heating therein. Normally, an electric heater that can easily control the temperature and the atmosphere is used. Further, the first furnace, the intermediate chamber, and the second furnace are provided with means for moving the object to be heated, for example, a conveyor such as a belt conveyor and a roller conveyor, a pusher, and the like. The furnace is provided with means for controlling its atmosphere. This generally comprises means for measuring the concentration of a gas component, for example, oxygen, which serves as an index of control in the atmosphere, and means for supplying an inert gas into the atmosphere. Normally, it is preferable to provide a means for measuring an index gas and a means for supplying an inert gas in each furnace so that the atmosphere in each furnace can be controlled independently.

[0007] In each furnace, it is preferable to supply an inert gas so that a gas flow is formed from the outlet to the inlet. Since only a small amount of light gas is generated from the object to be heated in the latter furnace as described above, it is preferable that the latter furnace is slightly pressurized compared to the former furnace, and the gas of the latter furnace flows into the former furnace through the intermediate chamber. As a result, the amount of inert gas supplied to the former furnace can be reduced.

In the former furnace, a larger amount of gas is generated than in the latter furnace. However, the largest amount of gas is generated because the charged object is heated rapidly when it encounters a high-temperature atmosphere. It is a part near the entrance. Also, the gas generated in this part is heavy and tends to fall from the generating surface and stay near the floor,
In addition, when it comes into contact with a high-temperature object, it condenses to form deposits.
Therefore, in order to discharge the generated gas out of the furnace without diffusing into the furnace, it is preferable to provide an outlet at a relatively low temperature near the inlet of the former furnace and near the floor. If a discharge port is provided in a high-temperature portion where gas is generated, condensate adheres to the discharge port, and the discharge port is easily blocked.

In a preferred embodiment of the present invention, a preparatory chamber separated from the outside and the furnace by doors is provided at the entrance of the pre-stage furnace and at the exit of the post-stage furnace, and the object to be heated is charged into the pre-stage furnace through the preparatory chamber. And remove it from the latter furnace through the preparation room. This prevents the outside air from flowing into the furnace and the gas in the furnace from flowing out of the furnace when loading and unloading the heated object into the furnace, and reduces the atmosphere and pressure in the furnace. It is easy to maintain constant. It is preferable to provide an inert gas supply means also in these preparation chambers.

In another preferred embodiment of the present invention, a shield made of a good heat conductor such as a metal for separating the heating element from the object to be heated is provided inside the pre-stage furnace. As described above, in the former furnace, a large amount of heavy gas is generated from the object to be heated, and when this comes into contact with the heating element in the furnace, the gas condenses and carbonizes on the surface of the heating element, thereby contaminating the heating element. Condensed on the surface of the heating element
Accumulation of carbides makes it difficult to control the temperature and shortens the life of the heating element. Further, if the condensed / carbide material is separated from the heating element and falls, the object to be heated is contaminated. If a shield made of a good conductor such as metal is provided between the heating element and the object to be heated and the two are isolated from each other, heavy gas generated from the object to be heated reaches the surrounding heating element and contaminates it. Can be prevented. The shield has a circular or elliptical cross section so that the tar-like substance formed by contacting heavy gas with the surface does not fall as droplets and easily flows down the shield. It is preferably formed in an arc. The shield is preferably provided over the entire length of the former furnace, but may be provided only in a portion where gas generation from the heated object is severe.
However, in the case of partial installation, it is preferable that the gas generated in the portion where the shield is installed does not flow out to the portion where the shield is not provided.

It is sufficient that the shield has airtightness that substantially prevents gas generated from the object to be heated from reaching the surrounding heating element, and is not required to be completely airtight. For example, in the case of a shield made of a metal plate, it is only necessary that the joints of the members constituting the shield have a certain degree of airtightness.
When the shield is contaminated with tar-like substances, the contamination can be removed by blowing air into the furnace to burn the tar-like substances.

The present invention will be described more specifically with reference to the drawings. FIG. 1 is a plan view of a pusher type heating furnace according to the present invention. In the figure, reference numeral 1 denotes a first furnace, 2 denotes an intermediate chamber, and 3 denotes a second furnace. A preparation room 4 is provided at the entrance of the pre-stage furnace, and the object to be heated is put into the preparation room and is charged into the pre-stage furnace by the pusher 5. The preparation chamber 4 is provided with an inert gas supply means (not shown). The door between the preparation chamber 4 and the pre-stage furnace is opened, and before the object to be heated is charged into the pre-stage furnace by the pusher, the preparation room 4 is closed. The atmosphere can be harmonized with that of the former furnace. 6 is a supply port of inert gas to the former furnace,
Reference numeral 7 denotes a gas outlet from the former furnace. As shown in FIG. 2, the gas outlet 7 is provided at a lower position.

The heated object that has reached the rear end of the former furnace is sent out to the intermediate chamber 2 by a pusher 8. The object to be heated in the intermediate chamber 2 is sent to the downstream furnace 3 by the pusher 9. Since the intermediate chamber is not open to the outside air and the gas in the latter furnace flows into the former furnace through the intermediate chamber, the inert gas is maintained in an inert atmosphere by itself. An inert gas may be supplied from 16 to completely shut off the atmosphere between the first furnace and the second furnace. The post-stage furnace 3 includes a heating unit 10, a slow cooling unit 11, and a cooling unit 12, and a heating element is provided only in the heating unit. The slow cooling part is made of a heat insulating material thinner than the heating part, and the cooling part is made of a heat insulating material thinner than the slow cooling part, so that the temperature of the object to be heated gradually decreases due to heat radiation from the furnace wall. . The object to be heated that has reached the rear end of the latter furnace is sent out to the preparation room 14 by the pusher 13. The preparation chamber 14 is also provided with an inert gas supply means (not shown). Before opening the door between the preparation chamber 14 and the downstream furnace and sending out the object to be heated to the preparation chamber 14 by the pusher, the atmosphere of the preparation chamber is reduced. It can be matched with that of the latter furnace. Reference numeral 15 denotes a supply port of an inert gas to the downstream furnace.

FIG. 2 shows a pre-stage furnace 1 having a shield inside.
In the cross-sectional view of the example, in the figure, 17 is a heat insulating material constituting the furnace, and 18 is a heating element installed in the furnace. Reference numeral 19 denotes a tray that stores the object to be heated. Reference numeral 20 denotes a sliding surface of a tray which is a part of a shield, and is usually formed of a metal plate so that the tray can slide easily and has good heat conduction. Reference numeral 21 denotes a groove provided on the sliding surface, which drops fine powder and the like generated by friction between the tray and the sliding surface so as not to hinder the sliding of the tray. Reference numeral 22 denotes a part of the shield, and the upper surface is formed in an arc shape. This is also formed of a metal plate so that heat conduction is good. Reference numeral 23 denotes a gas extraction pipe, which is open near the sliding surface. Reference numeral 24 denotes a support for the sliding surface.

Since the continuous heating furnace according to the present invention has the above-described structure, the object to be heated containing the volatile carbonaceous component is heated in an inert atmosphere, and the volatile carbonaceous material is heated. It is suitable for continuously producing a carbon product substantially free of components.

[Brief description of the drawings]

FIG. 1 is a plan view of an example of a continuous heating furnace according to the present invention.

FIG. 2 is a cross-sectional view of a pre-stage furnace of an example of a continuous heating furnace according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pre-stage furnace 2 Intermediate room 3 Post-stage furnace 4 Pre-stage furnace preparation room 5 Pusher 6 Inert gas supply port 7 Gas outlet 8 Pusher 9 Pusher 10 Heating part of post-stage furnace 11 Slow cooling part of post-stage furnace 12 Cooling part of post-stage furnace DESCRIPTION OF SYMBOLS 13 Pusher 14 Preparation room of the latter furnace 15 Inert gas supply port 16 Inert gas supply port 17 Insulation material 18 Heating element 19 Tray 20 Shield (sliding surface) 21 Groove 22 Shield 23 Gas extraction pipe 24 Support of sliding surface body

Claims (4)

[Claims] 1. A continuous type in which an object to be heated moves inside for heating a carbonaceous material containing a volatile carbonaceous component to produce a carbon product substantially free of a volatile carbonaceous component. A heating furnace, in which a heating furnace heats an object to be heated to remove volatile carbonaceous components contained therein, and further heats the object to be heated through the former furnace to a higher temperature to carbonize the object. The furnace consists of at least two furnaces and a middle chamber interposed between them, and both the former furnace and the latter furnace have heating elements inside, and the inlet of the former furnace and the latter Doors are installed at the furnace outlet, and between the former furnace and the intermediate chamber and between the latter furnace and the intermediate chamber, and the atmosphere in the furnace can be controlled. Continuous heating furnace. 2. The continuous heating furnace according to claim 1, wherein the pre-stage furnace is provided therein with a shield made of a good conductor for isolating the heating element and the object to be heated. 3. The continuous heating furnace according to claim 1, wherein a gas outlet from the former furnace is provided near an inlet of the former furnace and near a floor surface. 4. The continuous heating furnace according to claim 1, wherein a gas flow in the first furnace is directed from an outlet to an inlet.