JPH0289988A - Tunnel furnace for secondary firing of graphite materials - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention provides a method for manufacturing artificial graphite electrodes, etc.
This invention relates to a tunnel furnace that is effective for secondary firing of pitch-infiltrated graphite material.

[Conventional technology]

Tunnel furnace firing of pitch-infiltrated graphite material is carried out by loading the graphite material to be treated in a sagger covered by a cart, and moving the cart sequentially through the tunnel furnace, which consists of a preheating zone, a firing zone, and a cooling zone. It is carried out. During this treatment, the pitch component that has entered the inside of the graphite material as a penetrating agent is eluted in large quantities by receiving heat at a temperature higher than the melting point in the preheating zone. The degree of elution of the pitch component is particularly severe when a backingless structure truck is used, and this leaks out of the sagger in a gas-liquid state, causing accidents in the furnace or pollution phenomena.

To overcome these drawbacks, the tar pitch escaping from the permeable material is transported from the combustion zone of the tunnel kiln to the system by flowing it down through a tar pitch outflow hole in the base of the trolley to a conveyor submerged in water inside the bit. A carbon material firing method using a tunnel kiln in which the carbon material is taken outside and fired has been proposed (Japanese Patent Publication No. 60-29642).

(i!1fl that the invention tries to solve) However,
In the case of the invention disclosed in Japanese Patent Publication No. 60-29642, it is necessary to immerse the conveyor mechanism in water inside the bit, so the conveyor member including the driving part deteriorates within a short period of time due to the 7g circulation conditions in the furnace. The phenomenon of shellfish scratches occurs. Therefore, there is a practical problem in that the conveyor mechanism must be frequently inspected and repaired in order to operate safely.

The present invention has an easy-to-understand structure that allows liquid pitch components eluted and flowing down the sagger to be smoothly led out of the system and separated and collected without installing a mechanical transport mechanism inside the system. This is a tunnel furnace.

(Means for Solving the Problem) That is, the tunnel furnace for secondary firing of graphite material according to the present invention has a furnace length range corresponding to at least the preheating zone of the hearth located directly below the pitch outflow nozzle of the cart. It consists of a structure in which a concave flow channel with an inclined surface is laid and water flows continuously through the concave flow channel.

In the above structure, the sloped lower end of the concave flow channel is communicated with the pitch collecting tank, and the pitch collecting tank and the sloped upper end of the concave flow channel are connected by a water pipe via a pump, thereby allowing flowing water to flow I! By configuring a route, collection and collection can be carried out even more smoothly.

[Function] The liquid pitch component generated during transport through the tunnel furnace passes through the pitch outflow nozzle of the truck and falls into the flowing water of the concave flow channel. When falling, the pitch component is broken into droplets, contacts the flowing water, and is transported along with the flowing water while solidifying. During this time, the pitch component is subjected to flow and condensation action and is rapidly granulated into spherical particles having a diameter of about 1 to 5II11. Therefore, after that, depending on the state of the small spherical pitch, the particles naturally self-translocate along the slope of the concave flow channel and are automatically discharged to the collection system.

〔Example〕

The present invention will be described below based on an illustrated embodiment.

FIG. 1 is a schematic vertical cross-sectional view of a tunnel furnace according to the present invention, and FIG.
The figure is a cross-sectional view showing the preheating IFM of the furnace.

In the figure, l is the furnace wall, 2 is a truck that moves through the furnace in a connected state, and 0 truck 2 is a sagger 4 having a gas discharge hole 3 at the top.
is covered on a pedestal 7 via a saucer 6 loaded with graphite material 5, and a skirt plate 8 is inserted into a sliding sand seal device 9 on the furnace wall to block the atmosphere above and below the pedestal. Travels on track 10. The saucer and the base 7 are provided with one or more pitch outflow nozzles 11.11' each communicating with a central position.

The pipe 2 is a gas outlet provided in the ceiling of the furnace, and is connected to the exhaust gas suction duct 13 above the furnace.

14 is a concave flow channel laid in the hearth located directly below the pitch outflow nozzle 11' of the cart, and is installed with an inclined surface that allows water to flow at least in the furnace length range corresponding to the preheating zone where pitch elution is significant. . The inclined shape is V as shown in FIG.
In addition to the mold tilt, it can also be designed to have a one-sided tilt. The concave flow channel 14 is formed by digging a bit groove in the hearth or by attaching a gutter made of a suitable metal material.

When operating the furnace, water is continuously allowed to flow through the concave flow channel 14.
The cart 2 sent into the preheating zone by the butcher device is heated, and pitch components begin to be eluted from the treated graphite material loaded thereon. The eluted pitch component flows down to the 6 sides of the saucer,
A part of the gas is vaporized and passes through the gas outlet 12 from the gas exhaust hole 3 in the upper part of the sago 4, and reaches an appropriate processing device through the exhaust gas duct 3.

The liquid pitch component accumulated in the saucer 6 passes through the pitch outflow nozzle 11' of the truck and falls into the flowing water of the concave flowing water fl14. During the N process, the pitch component is broken into droplets, comes into contact with running water, and is transported along with the running water while solidifying. During this time, the pitch component is granulated into a spherical shape with a diameter of about 1 to 5 m+w by the flow action, and is naturally transferred along the slope of the concave flow channel 14 at around 1.

The pitch elution phenomenon reaches its peak when the cart approaches the center of the preheating zone, and sometimes a large amount of liquid pitch flows out, but together with the cooling effect of the bottom of the reactor by running water, the flowing liquid pitch vaporizes. The above-mentioned flow discharge progresses extremely smoothly without any problems. This state continues until the end of the preheating zone, where the elution of the pitch component is completed.

Flowing water with solidified spherical pitch is sent to pitch collecting tank I.
5, the pitch components are separated and collected by a solid-liquid separation operation.The recovered pitch is reused as a penetrating material or fuel.

When constructing a flowing water circulation path, the water after solid-liquid separation is pumped up by the pump 16 and returned to the flowing water pipe 17 communicating with the inclined upper end of the concave water channel 14. With this circuit mechanism, the water can be continuously circulated and pitch flow discharge can proceed smoothly.

In this manner, the cart whose pitch elution has been completed continues to the firing zone where it undergoes firing treatment, and further passes through the cooling zone to complete its operation.

(Effects of the Invention) According to the present invention, the liquid pitch component flowing out to the bottom of the cart can be completely recovered using a simple furnace structure without a mechanical conveyance mechanism such as a conveyor, thereby eliminating the need for complicated inspection and repair. Safe and smooth furnace operation is guaranteed at all times.Furthermore, since the recovered pitch component can be reused as a penetrant or fuel, there are practical benefits in terms of pollution prevention and cost reduction.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical cross-sectional view illustrating a tunnel furnace structure according to the present invention, and FIG. 2 is a cross-sectional view showing a preheating zone of the furnace. l...furnace wall, 2...carriage, 3...gas discharge hole, 4...sagger 5...graphite material,
6... saucer, 7... pedestal, 8...
Skirt plate, 9...Sliding sand seal device, IO・
...Trajectory, 11...Pitch outflow nozzle, 12...
Gas outlet, 13...Exhaust gas suction duct, 14...
・Concave flow channel, 15... Pitch collection tank, 16.
... Pump, 17... Water pipe.

Claims (1)

[Claims] 1. A concave flow channel (14) having an inclined surface is laid in the furnace length range corresponding to at least the preheating zone of the hearth located directly below the pitch outflow nozzle (11') of the truck, A tunnel furnace for secondary firing of graphite material having a structure in which water continuously flows through the concave flow channel. 2. The sloped lower end of the concave flow channel (14) communicates with the pitch collection tank (15), and the pitch collection tank and the sloped upper end of the concave flow channel are connected by a water pipe via a pump (16). 2. The tunnel furnace for secondary firing of graphite material according to claim 1, wherein the tunnel furnace for secondary firing of graphite material comprises a running water circulation path.