JPS60233492A - Continuous caliciner - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a continuous firing furnace that can continuously perform firing in an inert gas atmosphere without stopping the heat generation of the heat source in the firing chamber, and is of a pallet circulation type.

<Prior Art> Some conventional firing furnaces fired fine ceramic products at extremely high temperatures of around 2,000°C, and stabilized zirconia was used as a heat-resistant lining material. This firing furnace is expensive, and has the disadvantage that the stabilized zirconia short fibers peel off finely like chalk.

In conventional ultra-high-temperature firing furnaces for firing fine ceramic products, the furnace temperature at which long-term durability can be maintained is approximately 1.600°C. Moreover, it was not a continuous firing furnace.

<Objective of the Invention> The present invention has been made in view of the above points, and is inexpensive to manufacture by using carbon ceramics instead of stabilized zirconia as a heat-insulating lining material and by using a carbon heater. , about 2,000℃ ~2
．． It has sufficient durability for a practical period of time even at ultra-high temperatures in the range of 600℃, and can perform fully automated pallet circulation, making it easy to load and unload objects to be fired onto and from pallets. The present invention provides a continuous firing furnace that is a pallet circulation type that saves labor to the point where it can be completely unmanned by using a robot to perform firing in an inert gas atmosphere.

<Structure of the Invention> The continuous firing furnace of the present invention has three chambers (1°2. 3) are installed in series, and the second door (4) is the entrance door of the pallet feeding chamber (2), and the door body is made of carbon plate.
) and a second layer (5) that freely partitions the firing chamber (1), and a third layer (6) whose door body is made of a carbon plate and freely partitions the firing chamber (1) and the pallet discharge chamber (3). A fourth layer (7) is provided as the exit door of the pallet discharge chamber (3), and the baking chamber (1) and pallet feeding chamber (2) have a heat-resistant wall (8) made of carbon plate in the innermost layer. is lined.

As a result, a heat-resistant and heat-insulating wall (9) of a required thickness made of sealed carbon felt protects the casing (lO), and furthermore, the heating means (11) of the firing chamber (1)
A pallet return table (12) is made of a carbon heater and is installed insulated against the heat-resistant wall (8), and connects the pallet feeding chamber (2) and the pallet discharging chamber (3).
The table (12) and the three chambers are provided with an annular groove (13°, 14, 15.
16), the annular groove (13°14.15.16)
Inside, the part (14°15) corresponding to the above-mentioned firing chamber (1) and pallet feeding chamber (2) is made of carbon fired material, and the annular groove (13, 14, 15, 16) is made of carbon firing material. The pallet (P) is driven in the required order to each corner where the pallet feeding chamber (2) and pallet ejection chamber (3) are located, and to each of the two corners of the pallet return table (12).
) for circulating pallet transport means (17, 18, 19, 2
0) is attached, and the pallet transfer means (18) at the corner of the pallet feeding chamber (2) is a screw-type butcher device. ) is provided with an inert gas filling device (21) that independently fills each of them with inert gas.

Therefore, the second door (4) and the fourth layer (7) are the same as the second layer (5).
) and the third layer (6) is opened from the closed state, the pallet (p) on the pallet return table (12) (7) is supplied to the pallet feeding chamber (2), and the pallet discharging chamber (3) The pallet (P) of the pallet return table (1
2), and then the second layer (5) and third layer (6) are sent to the pallet feeding chamber (after the second door (4) and fourth layer (7) are closed. 2) and pallet discharge room (3)
is filled with inert gas, it opens, and the pallet CP) in the pallet feeding chamber (2) is sent into the baking chamber (1), and the pallet h (P) in the baking chamber (1) is transferred to the pallet discharge chamber (3). ), and the third ring (5
) and the third ring (6) are closed, and the pallet (
When the object to be fired (W) on P) is fired for a predetermined period of time,
The third door (4) and the fourth ring (7) will open.

Then, the firing chamber (1) is sealed with a heat-resistant wall (8) made of carbon plate and a heat-resistant/insulated wall (9) of the required thickness made of carbon felt, making it practical even at ultra-high temperatures of 2,000 degrees Celsius or more. It is constructed with a special double structure of carbon ceramics that can withstand a sufficient long period of time, and the heating means (11) of the firing chamber (1) is also composed of a carbon heater, so the furnace manufacturing cost can be significantly reduced, and the pallet ( 2.0 while the object to be fired (W) on P) passes through the firing chamber (1).
It becomes possible to perform firing at an extremely high temperature of 00°C or higher.

<Example> Below is one example of the present invention! 1. An embodiment of the subsequent firing furnace will be described with reference to FIGS. 1 and 2.

First, the configuration will be explained.

FIG. 1 shows an overall plan view. These three chambers 1, 2.3 are arranged in series so that the pallet i/feeding chamber 2 and the pallet ejection chamber 3 are located before and after the tunnel-shaped firing chamber l.
Door No. 4 (outer door), which is the entrance door of
A second ring 5 (inner door) that freely partitions the firing chamber 1, and a third ring 6 (inner door) that freely partitions the firing chamber 1 and the pallet discharge chamber 3.
A fourth ring 7 (outer door) which is an exit door of the parent discharge chamber 3 is provided. These doors can be raised and lowered by air cylinder devices (not shown) provided above.

A pallet return table 12 connecting the pallet feeding chamber 2 and the pallet discharging chamber 3 is provided, and the table 12 and the three chambers 1, 2.3 are connected to an annular groove 13 through which the pallets P flow.
, 14, 15.16, and an annular groove 14, 15.16.
is made of carbon fired material.

Also, part of the corners of the annular grooves 14 and 16 in the pallet feeding chamber 2 and pallet discharge chamber 3 and the pallet return table 12
A part of the corner of the annular groove 13 is provided with a pallet transfer means 1.
7.18, 19.20 are attached, and the pallet transfer means 18 is a screw type pusher device.1. <The let transport means 17°19.20 is an air cylinder device, and by driving these in the required order, the pallets P
are circulated in the annular grooves 13, 14, 15, and 16 as follows: pallet return table 12 - pallet feeding chamber 2 flash firing chamber 1 - pallet discharge chamber 3 - pallet return table 12. .

The relationship between the pallet return table 12 and the annular groove 13 is such that the pallet return table 12 has the annular groove 13, and in the figure, the annular grooves 13, 14.
13 and 16, 14 and 15, and 15 and 16 are separated, respectively, and are integrally connected to the annular groove 15.16. However, the first 1R4 (outer door), the second mark 5 (inner door)
And the fourth ring 7 (outer door) is completely sealed, and the third ring 6 (
The inner door (inner door) is lowered and closed to the extent that it does not interfere with the mutually abutting sides of the barrel (inner door) P, thereby substantially sealing the baking chamber l and the pallet discharge chamber 3.

The annular grooves 13, 14, 15.16 are annular grooves 13.14.
, 15, 16. The pallet return table 12 is fixed to the central part 12 so that the pallet return table 12 is fixed to the
A is extendable and can be expanded and contracted corresponding to the firing chamber l.

The firing chamber 1 includes a firing section 1a having a heating means 11 connected to an external power source, a preheating section 1b in front of the firing section 1a having no heating means 11, and a descending wall 2 made of carbon ceramics.
2 blocks the radiation light from the heating means 11 from entering the wall 2.
It consists of an annealing section IC for annealing the object to be fired W placed on a pallet P passing under the oven 2. Down wall 22
is attached so as to be freely adjustable to the extent that it does not interfere with the pallet P and the objects to be fired W placed thereon.

FIG. 2 shows a sectional view of the firing chamber l. In this figure, the casing lO of the firing chamber 1 is divided into a lower casing 101 and an upper casing 102, so that the lining materials 8 and 9 provided inside and the heating means 11
It is possible to install and update the annular grooves 13°, 14, 15, 16, etc. Lower casing 101 and -E
The casing 102 has inner walls 101a, 102a and an outer wall 101b, both of which can be cooled by flowing water between them.

It has a double wall structure consisting of 102b. This casing 10 is made of stainless steel. The inner surface of the casing 10 is first lined with a heat insulating wall 40 made of short polycrystalline alumina fibers with a thickness of 100 mm that can withstand high temperatures of 1,700°C, and then with a heat insulating wall 40 of about 70 mm.
A heat-resistant heat-insulating wall 9 made of carbon felt (carbon ceramics) with a thickness of

Note that, as can be seen from FIG. 1, such a wall structure is also constructed for the pallet feeding chamber 2. The pallet discharge chamber 3 has a double-walled casing 10 consisting of an inner wall and an outer wall made of stainless steel, which allows water to flow between the walls to cool the inside, and a heat-resistant wall 8. Heat-resistant/insulated walls9. A heat insulating wall 40 is not provided. Third layer 5 (inner door) and third layer 6
(Inner door) The door bodies 5a and 6a are made of carbon plates, and the frames 5b and 6b are made of stainless steel. Also, No.
The door 4 and the fourth door 7 have door bodies 4a, 7a and frame bodies 4b, 7b.
Both are made of stainless steel.

In short, the door bodies 5a of the second and third layers 5 and 6.

6a, heat-resistant wall 8. #Heat/insulation wall 9 and annular groove 13.1
4, 15, and 16 are all made of carbon ceramics, so they were chosen to have a durability that is sufficient for practical use even when the temperature is raised to an extremely high temperature of about 2,000°C or higher.

The heating means 11 is heated to 3.000°C in an inert gas atmosphere.
A carbon heater capable of heating at ultra-high temperatures as described above is employed, and an electrode passing pipe 23 is provided by fitting the inner wall 101a and the outer wall 101b of the lower casing Ioi.
and an electrode rod 25 made of carbon ceramics, which is attached to the inner wall 101a, connected to this pipe 23, and passed through a pipe-shaped heater hooking member 24 made of carbon ceramics that extends until it fits through the heat-resistant wall 8. ing. Thus, the heating means 11 is separated from the heat-resistant wall 8 for insulation. In this regard, if the carbon heater 11 is attached closely to the heat-resistant wall 8, the current of the carbon heater 11 will flow to the carbon plate 8, making it impossible to raise the temperature of the carbon heater 11 to an extremely high temperature of 2,000° C. or higher. Although not shown, the outer end of the electrode rod 25 is cooled with water and is connected to a power cord 26.

The heat-resistant material and the heat-resistant and heat-insulating wall 9 abut against the side surfaces of the annular channels 13, 14, 15, 16 laid on the heat-insulating wall 9.

Referring back to FIG. 1, the lower casing 10 serves as a passage for filling the firing chamber 1 with inert gas.
The pipe 27 is fitted through the inner wall 101a and the outer wall 101b of 1, and the pipe 27 is attached to the inner wall 101a.
There is a pipe 28 made of carbon ceramics that is connected to the pipe 27 and extends until it fits through the heat-resistant wall 8.
A pipe line 29 of the inert gas filling device 21 is connected to the pipe line 29, and a solenoid valve 30 is provided in the pipe line 29, and a similar pipe 31. is provided as a passage for discharging the filled inert gas.
There is a solenoid valve 3 in a conduit 33 connected to the pipe 31.
4 is provided, and the end of the conduit 33 is located at a high place. The above-mentioned pipes 27, 28, 31, 32 are provided not only in the baking chamber 1 but also in the pallet feeding chamber 2 and the pallet discharging chamber 3.

Furthermore, in order to quickly fill the pallet feeding chamber 2 and the pallet discharging chamber 3 with inert gas, a vacuum generator (vacuum pump) 35 is attached to keep both chambers in a vacuum, and a conduit 36 is connected via a solenoid valve 37. The pipe 38 is connected to a pipe 38 attached to each chamber 2, 3, and the pipe 38 is further connected to a pipe 39 made of carbon ceramics, and by opening the solenoid valve 37,
The pallet feeding chamber 2 or the pallet discharging chamber 3 can be evacuated. Since the third door 6 is not completely closed, the firing chamber 1 can also be evacuated from the pallet discharge chamber 3 side, and after being evacuated, it can be filled with inert gas. This allows for quick filling. The solenoid valve 37 is configured to close when the pallet feeding chamber 2 and the pallet discharging chamber 3 reach a predetermined degree of vacuum.

The inert gas filling device 21 uses a nitrogen cylinder as an inert gas source, and as mentioned above, the inert gas filling device 21 is connected to the firing chamber worker and pallet feeder through the solenoid valve 30 for gas injection and the solenoid valve 34 for gas release. Each of the chamber 2 and the pallet discharge chamber 3 can be filled with nitrogen gas. The opening and closing of the solenoid valves 30 and 34 of the inert gas filling device 21 and the opening and closing of the solenoid valve 37 of the vacuum generator are linked so that when one is closed, the other is open.

The third door 4 and the fourth layer 7 are opened after the third track 5 and the third track 6 are closed and the firing chamber 1, pallet feed chamber 2, and pallet discharge chamber 3 are isolated. There is. Also,
The third trace 5 and the third trace 6 remain until the third door 4 and the fourth layer 7 are closed, and the pallet feeding chamber 2 and pallet discharge chamber 3 are evacuated and further filled with nitrogen gas. , is now locked in the closed position. Then, a sensor (not shown) detects that it is filled with nitrogen gas,
Moreover, it opens only after the required time set by the timer has passed. In addition, a viewing window, an in-furnace temperature detector, a radiation prevention door, etc. (not shown) are also provided. Although not shown, a pallet P is placed beside the pallet return table 12.
It is assumed that an industrial robot is installed for loading the object W to be fired and taking down the fired product.

Here, the reason for selecting the members used in the above configuration will be explained.

Carbon fired material refers to carbon molded material with an angle of about 3.000°.
It is graphitized and fired at an ultra-high temperature of C. Carbon felt is made by intertwining short carbon fibers into a felt shape and manufacturing it for about 3,000 minutes in a vacuum or inert gas atmosphere.
It is fired at an ultra-high temperature of C or higher, and there is almost no shrinkage even when heated to approximately 2,000 to 2,600 degrees Celsius in an inert gas atmosphere, and because it has a felt structure, it is not only heat resistant. Experimental results showed that it also has excellent heat insulation properties. In addition, it is flexible and lightweight, making it easy to install and suitable as a lining material for the firing chamber 1. The carbon plate of the heat-resistant wall 8 may be made of either carbon fired material or carbon molded material. Carbon molding material is made by press-molding carbon powder graphitized at ultra-high temperatures at room temperature.

The structure is such that the heat-resistant/insulating wall 9 made of carbon felt is sealed from the inside with the heat-resistant wall 8 made of a carbon plate, because when it is not covered with the heat-resistant wall 8, the carbon felt of the heat-resistant/insulating wall 9 decomposes little by little and is placed on the pallet P. This is because it was found through experiments that the object W to be fired turns black due to carbon powder, and when the heat-resistant Φ heat-insulating wall 9 of carbon felt is not used between the heat-resistant wall 8 of the carbon plate and the casing 10, approximately This is because the heat insulation against the firing temperature of 2,000°C to 2,600°C is insufficient.

Next, we will discuss the effect.

Now, the pallets (P) being moved through the annular grooves 13, 14, 15. It exists from the extrusion end position to the extrusion start position of the air cylinder device 17. In addition, all the doors 4.5, 6.7 are closed, and the firing chamber 1, pallet feeding chamber 2, and pallet discharging chamber 3 are evacuated by the vacuum generator 35 and then by the inert gas filling device 21. It is assumed that the carbon heater 11 is filled with nitrogen gas and then heated to a high temperature.

First, the third door 4 and the fourth layer 7 are opened. At this time, the vacuum generator 35 is activated, and the pallet feeding chamber 2 and pallet discharging chamber 3 are drawn so that less nitrogen gas flows out from the door, and is discharged to the atmosphere in a safe place. Therefore, the air flowing into the pallet feeding chamber 2 and the pallet discharging chamber 3 cannot enter the baking chamber 1 because the baking chamber 1 is filled with nitrogen gas and has a positive pressure.
．． It is guaranteed that ultra-high temperatures of 000°C or higher can be maintained continuously.

Then, when door No. 4 opens, pallet return table 1
The pallet P on which the to-be-fired material W is placed at the extrusion start position of the air cylinder device 17 on the air cylinder device 17
After the air cylinder device 17 is driven to retire, the first door 4 is closed, and the pallet feeding chamber 2 is evacuated by the vacuum generator 35. Inert gas filling device 2 after being drawn
1 is filled with nitrogen gas.

Furthermore, when the fourth door 7 opens, the pallet P in the pallet discharge chamber 3 is sent out to the extrusion start position of the air cylinder device 20 on the pallet return table 12 by the extension drive of the air cylinder device 19 (first stage Then, after the air cylinder device 19 is driven to retire, the fourth door 7 is closed, and the pallet discharge chamber 3 is evacuated by the vacuum generator 35. Nitrogen gas is filled by the active gas filling device 21 .

When the pallet feeding chamber 2 and the pallet discharge chamber 3 are filled with inert gas, the second door 5 and the third door 6 are opened, and the pallet in the pallet feeding chamber 2 is opened by the extension drive of the screw type pusher device 18. At the same time, the pallet (P) closest to the pallet ejecting chamber 3 in the baking chamber 1 is sent to the pallet ejecting chamber 3, and the screw-type pusher device 18 is driven to retire. , the second door 5 and the third door 6 close.

When the second door 5 and the third door 6 are closed and the object to be fired W on the pallet P is fired in the firing chamber l for a predetermined period of time, the second door 4 and the fourth door 7 are opened again.

In this way, by repeating the above-mentioned operations, the objects W to be baked are placed on the pallet P and sent into the baking chamber 1 one after another, and each object is preheated by radiant heat in the preheating section 1b. from.

2.000 by carbon heater in baking section 1a
It is fired at an extremely high temperature of .degree. C. or higher, then slowly cooled in an annealing section IC where radiant heat is blocked, and then cooled in a pallet discharge chamber 3. In addition, the baking time of the baked product W may be adjusted by a timer for setting the time to open the second door 5 and the third door 6.

Finally, the fired product is taken down by an industrial robot (not shown) at the position pressed by the air cylinder device.

Modification> The firing chamber l may not have a preheating section or a slow cooling section, or a cooling chamber may be provided between the firing chamber l and the pallet discharge chamber 3. The annular grooves 13, 14, 15 and 16 are constructed without being divided, and the third door 4. The second door 5 and the fourth door 7 do not need to be completely sealed.The inert gas filling device 21 is not limited to a nitrogen gas cylinder, but may be equipped with an externally inert cylinder such as argon gas. That's fine.

Effects of the Present Invention> As explained above, the continuous firing furnace of the present invention has the following features: the firing chamber, the pallet feeding chamber, the pallet discharging chamber, and the pallet return table are connected to each other so that they can be freely partitioned by a door; The chamber is individually filled with inert gas by an inert gas filling device, and a pallet feeding device is attached to the pallet feeding chamber.
A pallet feeding device is attached to the pallet discharging chamber, and when the entrance door of the pallet feeding chamber and the exit door of the pallet discharging chamber are closed, the entrance and exit doors of the baking chamber are opened and the pallet feeding device transports the pallet into the baking chamber. At the same time as feeding, the pallet fired in the firing chamber is sent out to the pallet discharge chamber, and when the entrance and exit doors of the firing chamber are closed, the pallet sending device sends out the pallet fired in the firing chamber to the pallet discharge chamber. With this configuration, it is possible to realize a continuous firing furnace with a pallet circulation type and inert gas atmosphere that can perform pallet circulation fully automatically. If this process is carried out by industrial robots, it will be possible to provide a bi-technological continuous kiln that saves labor to the point where it can be completely unmanned.

In particular, in the continuous firing furnace of the present invention, the inner heat-resistant lining material is formed into a two-layer structure in which carbon felt is covered from the core side with a carbon plate, and the carbon heater is connected to the carbon heater with a heater hooking member made of carbon fired material. It has a configuration that allows it to be installed without contacting the plate and to supply power with an electrode rod made of fired carbon material.It was realized by using carbon ceramics, which is easier to process and install, and is cheaper, instead of stabilized zirconia. It is something that
The carbon heater is separated from the carbon plate to insulate the penetration part, and the carbon plate covers the carbon felt.

Furnace manufacturing costs can be significantly reduced, the current flowing to the carbon heater does not flow to the carbon plate or carbon felt, and even if the temperature is raised to an extremely high temperature of approximately 2,000℃ or more, it can withstand a sufficient period of time for practical use, and has good insulation. It is possible to provide a continuous firing furnace which is a pallet circulation type and has a structure in which fine ceramics to be fired are not blackened by carbon powder and is fired in an inert gas atmosphere.

[Brief explanation of drawings]

FIG. 1 is a partially sectional plan view of a continuous firing furnace according to an embodiment of the present invention, and FIG.
It is a sectional view taken in the direction of arrow II. P... Pallet, W... Item to be fired, l... Baking chamber, 2...φ pallet feeding chamber, 3φ... pallet discharge chamber. 4... No. 1 door. 5...Third trace, 6...Third trace. 7.-#Fourth door, 8... Heat-resistant wall made of carbon plate, 9... Heat-resistant 9 heat-insulating wall made of carbon felt 11... Carbon heater, 24.Φ.Heater hanging member, 12-φ・Pallet return table, 13.14, 15.16-... Annular groove path, 17.18,
19.20--Pallet transfer means 21...Inert gas filling device, patent applicant Dengen Yakin Kogyo Co., Ltd.

Claims (1)

[Claims] Pallet feeding chambers (2) are provided before and after the tunnel-shaped firing chamber (1).
) and the pallet ejection chamber (3).
1, 2, 3) are installed in series, and a pallet feeding room (2)
A second door (4) whose door body is made of carbon plate and which freely partitions the pallet feeding chamber (2) and baking chamber (1), A second mark (6) which freely partitions the firing chamber (1) and the pallet discharge chamber (3), and a fourth door (7) which is the exit door of the pallet discharge chamber (3) are provided. The chamber (1) and the pallet feeding chamber (2) are lined with a heat-resistant wall (8) made of a carbon plate as the innermost layer, and are sealed with a heat-resistant and heat-insulating wall (9) of the required thickness made of carbon felt. protects the casing (10), and furthermore,
The heating means (11) of the baking chamber (1) is made of a carbon heater and is installed insulated against the heat-resistant wall (8), and the pallet feeding chamber (2) and the pallet discharging chamber (3) are connected to each other. A return table (12) is provided, and the table (12) and the three chambers have an annular groove (13, 14° 15, 16) through which the pallet (P) flows; 14゜15.16), the above firing chamber (1)
and the parts (14, 15) corresponding to the pallet feeding chamber (2)
is made of carbon fired material, and the annular groove (13,
14, 15, 16), the pallets (P ), and the pallet transport means (18) at the corner of the pallet feeding chamber (2) is a screw type pusher device. An inert gas filling device (21) that independently fills at least the firing chamber (1) and the pallet feeding chamber (2) with inert gas.
A continuous firing furnace characterized by being equipped with.