JPS6236074Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a refractory having a specific shape, particularly to a refractory having a specific shape that is convenient for use as a receptacle brick for a heating furnace.

Tunnel furnaces and batch furnaces used for firing ceramic products, glass kilns and metal melting furnaces, steel heating furnaces and soaking furnaces used for processing and heat treating steel products, etc.
Since the objects to be heated are heated under hot air at a high temperature of 800℃, especially 1200℃ or higher, the walls of these heating furnaces are coated with refractory and heat insulating materials, such as 1.5m thick, to withstand such high temperatures. A complicated and multi-layered structure is required, and the temperature in the ceiling is particularly high, resulting in a thicker and heavier furnace wall structure.At the same time, in order to support such heavy objects, not only the ceiling but also the side walls must be constructed. It requires a solid structure,
Simply put, the quality, quantity, and space required for furnace construction were expensive. On the other hand, when operating such a heating furnace, since the heat capacity of the furnace wall is large, it takes a long time and a large amount of heat to raise the temperature at the start of operation, and in order to maintain a predetermined high temperature, a large amount of heat is required from the furnace wall. The heat loss is extremely large, and the heat loss that is carried away by the exhaust gas, which is still quite hot in proportion to the amount of hot air that is sent in, is also large, and there are problems such as the need to install a separate heat exchanger to recover heat from this exhaust gas. It had a point.

The present invention provides a refractory having a specific shape to solve these problems.In other words, the present invention has an outer shape of a substantially rectangular parallelepiped cut by a slope parallel to one edge and not including the edge. The present invention provides a refractory characterized in that a plurality of channels are provided that communicate with one surface including the one edge and the slope.

The present invention will be explained below based on the drawings.

As shown in Figure 1, the furnace side walls 1 are constructed of high-quality refractories such as alumina bricks, and are supported by suspension beams 5 from beams 4 of a frame 3 constructed of steel. In the tunnel furnace having the constructed furnace ceiling wall 2, headers 6, 6' and refractories 7, 7', which are embodiments of the present invention, are arranged on the furnace side walls near the ceiling.
An inner wall 9 made of serpentine bricks 8 is constructed in an arch shape between the facing refractories 7 and 7' of the same shape.

The seri bricks 8 are in the shape of a right rectangular column with an isosceles trapezoidal cross section, with the long bottom of the trapezoid facing toward the furnace ceiling and the short bottom facing toward the inside of the furnace. In addition, the seri brick 8 is provided with a plurality of exhaust gas passages communicating between the upper base and the lower base, and a plurality of air passages communicating between both slopes, so-called orthogonal heat transfer. It forms a body unit.

The refractory 7 has a shape as shown in FIG. That is, three edges 7j-7g, 7j-7b,
One edge 7 in the approximately rectangular parallelepiped defined by 7j-7i
A slope 7c- parallel to j-7i and not including the edge
It has an outer shape cut by 7d-7e-7f (hereinafter referred to as the auction receiving surface 13), and one side including the edge 7j-7i-7a-7b (hereinafter referred to as the header surface 14) and the auction receiving surface. A plurality of channels 10 communicating with each other have pentagonal side surfaces 7a-7d-7e.
-7h-7i and 7b-7c-7f-7g-7
It is provided parallel to j. This refractory 7 is surface 7
h-7i-7j-7g as the bottom surface, surface 7a-7b
-7c-7d is the upper surface, and together with alumina bricks and the like stacked above and below, the furnace side wall is constituted. The header surface faces the outside of the furnace and contacts the opening surfaces of the headers 6, 6', and the seri bricks 8 are successively stacked on the seri receiving surface to form an arch of the inner wall. Similar refractories 7 are arranged side by side on the two sides. The opening position of the air passage in the seri brick is configured to substantially match the opening position of the air passage 10 on the seri receiving surface of the refractory 7.

The hot air of approximately 1,400°C that is sent into the furnace heats the items inside the furnace, and then becomes exhaust gas of approximately 1,300°C, which flows through the numerous exhaust gas passages provided in the seri bricks from the inside of the furnace on the inner wall to the ceiling. It passes slowly to the side,
The gas is discharged to the outside of the furnace through an exhaust duct (not shown) that opens into the space between the furnace ceiling wall 2 and the inner wall 9.
On the other hand, air to be preheated is led from outside the furnace to the inlet header 6, passes through the flow path 10 of the refractory 7 on the inlet side, and flows through the numerous air flow paths provided in the seri bricks at an appropriate flow rate. During this time, the air is heated by exchanging heat with the exhaust gas, passes through the flow path of the refractory 7' on the outlet side, and is recovered as heated preheated air from the header 6' on the outlet side. Note that other suitable fluids may be flowed instead of air.

Such a heating furnace using the refractory of the present invention has the following effects. In other words, in a conventional heating furnace,
For example, the heating temperature inside the furnace is about 1400℃, but at most
High-temperature exhaust gas at approximately 1300°C, which is only 100°C lower, is discharged outside the furnace with a large amount of sensible heat, resulting in a large heat loss.In order to recover some of this heat loss, it is necessary to In contrast to the inconvenience of having to install a heat exchanger that can withstand new high temperatures, in such a heating furnace, heat can be exchanged easily and efficiently without mixing the exhaust gas and the fluid to be heated. , the exhaust gas passing through the inner wall is cooled to below 1000℃, while the temperature from room temperature to 100℃
The air introduced is preheated to approximately 500℃, depending on conditions, and heat can be easily recovered. In addition, in conventional heating furnaces, exhaust gas is extracted from a specific location on the ceiling, which creates a distribution of hot air flow rate and temperature between the specific location and other ceiling locations, which in turn causes the heating temperature of the article to vary. This has resulted in unevenness depending on the location within the furnace, the need to use different furnace materials depending on the location of the furnace wall, and differences in repair frequency. However, in such a heating furnace, the exhaust gas is discharged almost equally from each part of the inner wall over a wide area, so the above-mentioned drawbacks are eliminated, and a large area can be used for heat exchange, so the required amount of heat can be recovered with a thin inner wall thickness. can be achieved. Furthermore, since multiple exhaust gas flow paths and multiple air flow paths are provided independently over a wide area, even if some of these flow paths become clogged or otherwise damaged, the overall It also has the advantage of not causing any fatal damage to functionality.

Since the inner wall is forcedly cooled by fluid such as air, there is a considerable temperature difference between the inner wall of the furnace and the ceiling side, in other words, a highly functional cross-sectional layer is formed. At the same time, the average temperature of this inner wall also decreases, making it possible to obtain a ceiling structure that is extremely lightweight and simple compared to the conventional ceiling structure that is thickly covered with high-grade fireproofing materials and high-grade insulation materials. The strength required for the seri bricks 8 constituting the structure, the refractories 7 and 7' that support them, and also the side walls and frame is also reduced. In addition, since the temperature of the exhaust gas after passing through the exhaust gas flow path on the inner wall has decreased considerably, the furnace material that makes up the furnace ceiling wall has areas that are directly exposed to high-temperature hot air (for example, the furnace side wall in Figure 1). It is now possible to use materials of a lower grade than the furnace material, and the thickness of the furnace material layer, which conventionally required the ceiling to be thicker than the side walls, can be reversed by using the refractory of this invention. Can be made thinner. This also means that whereas conventionally the ceiling required a complex structure with overlapping layers, a simple suspended ceiling structure with one layer of furnace material,
Depending on the conditions, it is also possible to create a ceiling structure with only a steel plate outer skin. These things not only save furnace construction materials, but also lower the heat capacity of the furnace, making it easier to raise and lower the heat during furnace operation.

However, the external surface of the refractory of the present invention only needs to be substantially flat, and small protrusions or small recesses may be provided so that it engages with other bricks placed adjacently during use, or a part of the side surface may be The refractories of the present invention may be formed into a groove shape so that when the refractories of the present invention are placed adjacent to each other, this groove becomes a flow path. Furthermore, the term "substantially rectangular parallelepiped" as used in the present invention refers to a shape in which the inner surface 11 forms an angle slightly larger than a right angle with the bottom surface 12 as shown in FIG. 3, or one in which the inner surface 11 is gently curved as shown in FIG. This concept also includes cases where the outer shape has such a cross section, and it may be possible to connect more smoothly with the bottom surface of the seri bricks stacked on the seri receiving surface 13, thereby reducing the flow resistance of hot air. Figure 2, Figure 3,
The fact that the external shape is approximately a right pentagonal prism as shown in Figure 4 is that this refractory has no sharp angles, so it is less likely to be damaged during handling, and it is also possible to stack bricks on the top surface. This is preferable because it has the advantage of being able to hold and fix the refractory due to its weight. However, as shown in FIGS. 5 to 7, the external shape of this refractory may be a triangular prism or a quadrangular prism.

The shape, size, number, and
The channel spacing can be designed as appropriate by taking into consideration various factors such as the flow rate of the fluid flowing through the channel, the heat resistance and strength required of this refractory, and generally the cross-sectional area of the channel is 3 to 3. 60 cm ² and the number of channels is preferably 2 to 20. Regarding the distribution of the channels, they may be opened on the slope in a single lattice shape or in a stacked lattice shape, or they may be opened in layers parallel to the bottom surface or parallel to the side surfaces as shown in Fig. 2. .

Various materials such as cordierite, mullite, zirconia, silicon nitride, silicon carbide, and alumina can be used for the refractory of the present invention depending on the required heat resistance, heat insulation, strength, etc.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a tunnel furnace using a refractory according to an embodiment of the present invention. FIG. 2 is a perspective view of a refractory according to an embodiment of the present invention. 3 to 7 are side views of refractories according to different embodiments of the present invention. 1: Furnace side wall, 2: Furnace ceiling wall, 3: Frame, 6,
6': Header, 7,7': Refractory, 8: Ceramic brick, 9: Inner wall, 10: Channel, 11: Inner surface, 1
2: bottom surface, 13: auction receiving surface, 14: header surface.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a refractory having an outer shape of a substantially rectangular parallelepiped cut with a slope that is parallel to one edge and does not include the edge, between the one surface including the edge and the slope A refractory characterized by having a plurality of channels communicating with the refractory. (2) The refractory according to claim 1 of the utility model registration, which has an approximately rectangular pentagonal prism outer shape.