JPH05340674A - Multilevel roller kiln - Google Patents

Abstract

PURPOSE:To efficiently partition a firing chamber into firing regions which are independent of each other by a structure in which beams of heat-resistant ceramic are set across between roller conveyors and at right angles to the direction of their conveyance, a ceramic fiber board is mounted on the beams as a partition between the roller conveyors separating the chamber into separate spaces, and each of these spaces is equipped separately with a heating device and a temperature-controlling mechanism. CONSTITUTION:Inside a kiln roller conveyors 1, 2 are set at two levels, one over the other, and a partition 3 is provided therebetween so that the inside of the kiln is divided into an upper firing region 4 and a lower firing region 5 which are independent of each other. The partition 3 comprises beams 7 and panels; each of the beams 7 is of heat-resistant ceramic, being set at right angles to the direction of the conveyance of the roller conveyors 1, 2 with the two ends held by side walls 6 of refractory brick for support and arranged at specified intervals; each of the panels is formed of a ceramic fiber board 8 on each of whose two sides a heat-resistant ceramic plate 9 is superposed in a sandwichlike, three-ply structure and laid on the beams 7. Each of the resulting upper firing region 4 and lower firing region 5 is equipped with a heating device 10 and a temperature-controlling mechanism both of their own so that a firing condition differing for each of the firing regions 4, 5 can be maintained in firing objects 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller kiln (also called roller hearth) used for firing ceramic products and industrial ceramic products.

[0002]

2. Description of the Related Art A roller kiln is a roller conveyor provided in a furnace for carrying an object to be processed and continuously performing operations such as heating, firing, and heat treatment to mass-produce ceramic products and industrial ceramic products. It is a continuous heating furnace suitable for. Recently, in order to further increase the production amount with the same equipment installation area, a multi-stage roller kiln having upper and lower roller conveyors arranged has been studied. FIG. 2 is a drawing schematically showing a cross section of a conventionally used multi-stage roller kiln. In a conventional multi-stage roller kiln, as shown in FIG. 2, a plurality of roller conveyors 21 for transporting an object to be fired 24 are arranged vertically, and a heating device, for example, a burner 23 is used to form one object to be fired 24 in each step. The heating was performed under the same conditions in the firing region. However, although such a multi-stage roller kiln can increase the production amount, if the fired product falls from the upper roller conveyor or the upper roller is broken, the lower roller conveyor will be damaged. There was a problem that was spread. In addition, the firing conditions of each stage are basically the same, and there is a drawback that products that require different firing temperature conditions cannot be simultaneously produced.

[0003]

Although such a problem can be solved by partitioning the upper and lower roller conveyors, a feasible and economical means has not been shown yet. Japanese Unexamined Patent Publication (Kokai) No. 60-38581 suggests a two-stage roller kiln in which the inside of the kiln is divided into an upper layer and a lower layer by a specially shaped ceramic plate having a plurality of passages inside. However, this proposal also uses a special ceramic plate with a complicated shape, and blows hot air to the upper and lower layers in the kiln through the passages in the ceramic plate,
Questions remain regarding the individual controllability and economics of each stage. The present invention is
The present invention has been completed for the purpose of providing an economically installable multi-stage roller kiln which does not use a special constituent material, has a simple structure using a commercially available material, has a good control response, and can be installed economically.

[0004]

DISCLOSURE OF THE INVENTION The present invention is a multi-stage roller kiln having at least two series of roller conveyors at the top and bottom, and between the roller conveyors inside the kiln at predetermined intervals perpendicular to the transport direction of the roller conveyors. A heat-resistant ceramic beam is passed over, both ends are supported by side walls, and a ceramic fiber board with both sides sandwiched by heat-resistant ceramic plates is placed on this ceramic beam to partition between each roller conveyor, and heating is done in each partitioned space. Provided is a multi-stage roller kiln which is capable of forming a firing region by mounting a device and maintaining different firing conditions for each firing region. Furthermore, the ceiling of the uppermost stage in the roller kiln passes the beams of heat-resistant ceramics at a predetermined interval at right angles to the transport direction of the roller conveyor, and supports both ends by side walls. Provided is a multi-stage roller kiln having a ceiling formed by stacking ceramic fiber boards on the back surface of the ceramic plate.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the drawings showing the embodiments of the multistage roller kiln of the present invention. FIG. 1 is a cross-sectional view showing an embodiment example of a multi-stage roller kiln of the present invention. In the multi-stage roller kiln of the present embodiment example, the roller conveyors 1 and 2 are arranged in upper and lower two stages, and a partitioning part 3 is provided in the middle between the two, so that the inside of the kiln is independent from each other in an upper firing region 4 and a lower firing region 5. And separated. The partitioning part 3 is formed on a heat-resistant ceramic beam 7 whose both ends are supported and passed by side walls 6 of heat-resistant bricks at predetermined intervals at right angles to the conveying direction of the roller conveyor, and both sides of the ceramic fiber board 8 are heat-resistant ceramics. It is constructed by placing a panel having a sandwich-like three-layer structure which is superposed by a plate 9.

The cross-sectional shape of the beam 7 may be square or L-shaped. Normally, the vertical height of the beam 7 is 10 to 30 m.
m, and the spacing is 300 to 800 mm. Beam 7
For example, indentations are provided on the inner surface of the refractory heat-insulating brick that constitutes the side wall 6 of the roller kiln, and both ends thereof are inserted and supported. A suitable thickness of the ceramic plate 9 is about 10 to 20 mm. A ceramic material having heat resistance of at least 1000 ° C. or higher, that is, a silicon carbide ceramic material is usually used for the beam 7 and the ceramic plate 9, but in addition to this, silicon nitride, mullite, alumina, zirconia, or the like is used. You can choose a suitable material from the materials. As the silicon carbide-based ceramic, a commercially available ceramic containing about 90% by weight of silicon carbide and about 10% by weight of silicon is suitable. The ceramic fiber board 8 has a thickness of 50.
~ 300mm, maximum operating temperature is at least 100
It is preferable to use a commercially available alumina / silica-based fiber having a temperature higher than 0 ° C. The ceramic fiber board 8 may be a plate previously processed, or a ceramic fiber 9 may be spread on a ceramic plate 9 and another ceramic plate 9 may be superposed thereon to form a panel. Of course, the partition part 3 may be panelized by on-site construction.

The upper firing region 4 and the lower firing region 5 do not need to be completely sealed and separated by the partition portion 3 as long as the temperature can be adjusted substantially for each firing region. It is often necessary to avoid a large pressure difference between the firing regions. .. A heating device (burner) 10 and a temperature control mechanism (not shown) attached to the heating device 10 are attached to the upper firing region 4 and the lower firing region 5 partitioned in this way, and the firing target 15 is set in each firing region. It is possible to maintain different firing conditions. In the present embodiment, the known temperature control mechanism for burners can be used.

Further, it is preferable that the uppermost ceiling part 11 in the roller kiln is constructed in accordance with the partition part 3. That is, the heat-resistant ceramic beams 12 are passed at a predetermined interval at right angles to the conveying direction of the roller conveyor, and both ends are supported by the side walls 6, and the heat-resistant ceramic plate 13 is supported on the ceramic beams 12.
And put the ceramic fiber board 14 on the back surface. It is economical to use the ceramic fiber board 14 for high temperature and for low temperature, depending on the temperature.

[0009]

The multi-stage roller kiln of the present invention is provided with a partition between each stage and an independent heating device for each stage.
Since different firing conditions can be maintained, products with different firing conditions can be fired simultaneously. Further, the unused stages can be suspended, and even if a failure occurs in one stage, the other stages can operate regardless of this.
Of course, if the fired product falls from the upper roller conveyor to the lower stage, or if the upper roller is broken, the accident does not spread to the lower roller conveyors. The divider is easily designed, assembled and easily repaired using all commercially available materials. By adopting a structure that also complies with this partition for the topmost ceiling, it is economical compared to the ceiling constructed with conventional refractory bricks, which makes it easier to design, assemble and repair the ceiling, which is economical. ..

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of an embodiment of a multistage roller kiln of the present invention.

FIG. 2 is a drawing schematically showing a cross section of a conventional multistage roller kiln.

[Explanation of symbols]

1: Roller conveyor of the upper stage 2: Roller conveyor of the lower stage 3: Partition part 4: Upper stage firing area 5: Lower stage firing area 6: Side wall 7: Beam 8: Ceramic fiber board 9: Ceramic plate 10: Heating device 11: Top stage Ceiling part 12: Beam 13: Ceramic plate 14: Ceramic fiber board 15:
Burned material 21: Roller conveyor 22: Furnace body 23: Burner 24: Burned material

Claims (2)

[Claims] 1. A multi-stage roller kiln having at least two series of roller conveyors at upper and lower sides, wherein heat-resistant ceramic beams are passed between the respective roller conveyors inside the kiln at a predetermined interval at right angles to the conveying direction of the roller conveyors. Both ends are supported by side walls, and a ceramic fiber board whose both sides are sandwiched by heat-resistant ceramic plates is placed on this ceramic beam to partition between the roller conveyors, and a heating device is installed in each partitioned space to set the firing area. A multi-stage roller kiln that is formed and can maintain different firing conditions for each firing region. 2. The ceiling of the uppermost stage in the kiln passes a beam of silicon carbide based ceramics at a predetermined interval at right angles to the conveying direction of the roller conveyor, and both ends are supported by side walls, and the ceramic beam is heat-resistant. A multi-stage roller kiln according to claim 1, characterized in that it is formed of a ceiling on which a conductive ceramic plate is placed and a ceramic fiber board is laminated on the back surface of the ceramic plate.