JPH01201416A - Radiating panel - Google Patents

Abstract

PURPOSE:To simply form a radiating panel, which is suitable to a heating furnace, by forming the radiating panel hanging down from a roof of the heating furnace by suitably assembling a hang-down rod, slippage-preventing material and ceramic-made permeable block on a bottom plate. CONSTITUTION:Buffering material 15, such as ceramic fiber, is packed in one pair of grooves 13A arranged at both end parts of the bottom plate 13 and two pieces of the hang-down rods 12 are inserted. On the bottom plate 13 between two hang-down rods 12, plural pieces of the ceramic-made permeable blocks 11 having plural permeable holes and plural pieces of the slippage- preventing material 14 are alternately set by the desired number of stages and the radiating panel hanging down from the roof of the heating furnace for heating steel, etc., is formed. Further, at the upper part of this radiating panel, parting wall 16 is fitted and supporting rods 17 are mutually set between the parting walls 16 and it is desirable that a reflecting plate 18 is laid and fixed on the supporting rods 17. By this method, the radiating panel, which is suitable to the heating furnace for heating the material to be heated with high temp. gas, is simply formed.

Description

[Detailed description of the invention] The present invention relates to a radiant panel suitable for industrial heating furnaces.

Traditionally, radiation from the walls and high-temperature gas is used as a means of heat transfer in industrial heating furnaces that heat objects with a flow of high-temperature gas, but since gas inherently has low radiation, Heat transfer efficiency to the heated object in the furnace is low. Therefore, in order to accelerate heating in conventional industrial heating furnaces, the ceiling of the furnace must be raised to increase the thickness of the gas to increase the radiant power, or the surface area of the furnace walls must be increased to increase the radiant area. I have no choice but to do it. However, these methods increase the cost of constructing a furnace and also cause waste, such as an increase in heat dissipation to the surroundings.Also, the efficiency of heat transfer from high-temperature gas such as combustion gas to the heated object is low. The fact that it is low means that the temperature of the exhaust gas needs to be raised accordingly, which increases the heat loss carried away by the exhaust gas, and the heat utilization efficiency of conventional industrial heating furnaces is low. Considering the history, it was difficult to reduce furnace construction costs.

For this reason, with the aim of improving the heat utilization efficiency of industrial heating furnaces, it has been proposed to install a radiant panel inside the furnace and to use a ventilation block for this radiant panel.
In the radiant panels that have been proposed so far, even when installed, the heat transfer to the radiant panel and/or the heat radiation from the radiant panel to the heated object is small, and the heat utilization efficiency cannot be sufficiently improved. Furthermore, there are many problems with the structure and installation method of the radiant panel. These problems will be made clear by the description of the characteristics and effects of the heating furnace and the radiant panel using the radiant panel of the present invention.

An object of the present invention is to provide an industrial heating furnace using a radiant panel that can significantly improve heat transfer efficiency from high-temperature gas to an object to be heated by installing a radiant panel. The object of the present invention is to provide a radiant panel that is suitable for use in such an industrial heating furnace and can be easily installed on a vine.

The radiant panel of the present invention is a flat radiant panel that is installed suspended from the ceiling of a heating furnace that heats objects to be heated by a high-temperature gas flow, and the radiant panel includes a plurality of hanging rods, a slip prevention material, and a plurality of ventilation blocks made of ceramics having a large number of ventilation holes, the slip prevention material is disposed between the ventilation blocks, and a bottom plate 13 is disposed at the bottom. This is a radiant panel that is suspended by inserting the hanging rod therethrough.

In a preferred embodiment of the radiant panel of the present invention, the ceramic breathable block is a ceramic honeycomb.

In heating the object to be heated by a high-temperature gas flow in a heating furnace using the radiant panel of the present invention, the radiant panel is first heated by convective heat transfer from the high-temperature gas, and then the object to be heated is heated by the heat radiation from the radiant panel. is heated by radiation. A typical example of a ceramic breathable block fitted into a radiant panel is a ceramic honeycomb body having a large number of ventilation holes. The ceramic breathable block has a large number of ventilation holes, so hot gas can flow through the ventilation holes with low pressure drop, and the contact surface area with the hot gas is large. Heat is efficiently transferred to the panel.

The radiator of the present invention is placed, like a continuous steel heating furnace, on a support surface such as a hearth or skid rail, or a high-temperature gas flow flows at least above the object to be heated that moves on the support surface. ,
Therefore, when applied to a heating furnace for heating an object to be heated, it is easy to attach a radiant panel suspended from the ceiling.

Preferably, the plurality of ventilation holes in the ventilation block made of heat-resistant ceramic are provided generally parallel to the direction of hot gas flow within the furnace.

Then, high-temperature gases such as combustion gas and exhaust gas are passed through the ventilation holes of the radiant panel, and the heat is transferred from the high-temperature gas to the ceramic ventilation blower. It is preferable to use a honeycomb-shaped ceramic block with a cross-sectional area of about 10 x 10 cm, for example, which is relatively easy to manufacture, but one with a cross-sectional area several times this size is difficult to manufacture. Therefore, in order to create a radiant panel for use in a continuous steel heating furnace, etc., it is usually necessary to incorporate a large number of air permeable blocks made of honeycomb-shaped ceramics.

Since the radiant panel of the present invention is vertically suspended and held, it is easy to attach, and the radiant panel has a structure that is easy to assemble.

An embodiment of the radiant panel of the present invention is shown in FIGS. 1-3. This radiant panel has a plurality of breathable blocks 11, two hanging rods 12, and a plurality of anti-slip members 14, and furthermore, one bottom plate 13 is provided at the lowest stage to support the entire load. There is. The bottom plate 13 has a groove 13A on the upper side, and a buffer material 15 such as ceramic fiber is filled in the groove 13A to partially fill the groove 13A. The bottom plate 13 is suspended through two hanging rods 12 at both ends thereof. The upper end of the hanging rod 12 is fixed to the ceiling of the heating furnace, if necessary, via a connection such as a bottle. A plurality of (10 in the illustrated example) breathable blocks 11 are arranged side by side on the bottom plate 13 with their lower edges fitted into the grooves 13A, forming a first stage of breathable blocks. . In the illustrated embodiment, the anti-slip member 14 has approximately the same length and width as the bottom plate 13, and further includes holes at both ends through which the hanging rod 12 is inserted, and a lower edge of the breathable block on both the upper and lower sides. and a groove that fits in the upper edge,
Therefore, in this embodiment, as is clear from FIG. 4, the anti-slip member 14 has an H-shaped cross section. It goes without saying that the anti-slip material is not limited to this shape.

In the embodiment, after the first stage breathable block 11 is mounted on the bottom plate 13, the hanging rod 12 is inserted into the hole of the anti-slip material 14.
When the anti-slip material 14 is attached by inserting the anti-slip material 1
4 fits into the ventilation block 11, and the ventilation block 11 is fixed and prevented from slipping down.

Next, another plurality of air permeable blocks 11 are fitted into the grooves of the anti-slip material 14 and placed side by side on the anti-slip material I4 in the same manner, thereby forming the next stage of air permeable blocks. Further, in the same manner, mounting another anti-slip material 14 and another breathable block 11 can be repeated to obtain a radiant panel having a desired number of stages of breathable blocks 11. Note that the air permeable block constituting the radiant panel of the present invention is made of ceramics, and it is important that it has a large number of air holes that penetrate through the panel surface substantially perpendicularly.

In the illustrated embodiment, the hanging rod 12, the bottom plate 13, and the anti-slip member 14 are all made of ceramics, but depending on the conditions of use, they may be partially or entirely made of heat-resistant metal or the like. Moreover, the cross-sectional area of the breathable block 11 is 1
A cordierite honeycomb body measuring 0×10 cm and 2.5 cm thick is used. The ventilation holes in honeycomb-shaped breathable blocks usually have a typical diameter of 0.8 to 20 mm, and the thickness of the hole wall
Those with a thickness of about 0.1 to 3 mm can be easily manufactured and can be made relatively lightweight. The ventilation block in this example is 58
It has a honeycomb shape with a 5mm square hole and a hole wall thickness of 0.5n++n, and has many ventilation holes, and has low strength, but
A radiant panel having the structure as described above can be used satisfactorily.

The hanging rod 12 is a member that requires particularly strong strength, and is made of silicon carbide,
It is preferable to use a heat-resistant ceramic such as silicon nitride, alumina, or mullite, or a heat-resistant metal with a hollow interior, water or air cooling, and a heat-insulating coating.

Since the entire load of the breathable block 11, slip prevention material 14, etc. is applied to the bottom plate 13, it must have the strength to withstand this load.
Ceramics such as mullite with a required thickness are used.

Since the anti-slip member 14 usually does not require much strength, it can be made of a lightweight refractory such as mullite, or a ceramic such as a ceramic fiber molded product.

In addition, if the space between the object to be heated in the heating furnace and the ceiling of the furnace is too wide and there is no need to provide a radiant panel that covers almost the entire height, a radiant panel as shown in Figs. It is preferable to use this radiant panel and attach the partition wall 16 to the top of the radiant panel. Depending on the temperature conditions, the partition wall 16 may be made of a ceramic fiber molded board, a calcium silicate board, or the like. It is preferable that the partition wall 16 also be provided with a hanging rod insertion hole. Furthermore, in order to suppress heat transfer due to heat radiation from the radiant panel to the ceiling of the furnace, a reflector plate 18 is installed.
It is preferable to install the reflector in parallel to the ceiling of the furnace.In this case, the structure of installing the reflector is to install a support rod 17 between the partition walls 16 attached to the adjacent radiant panels, and to install a support rod 17 on top of the support rod 17. An example is a structure in which the reflecting plate 18 is mounted and fixed.

By configuring the radiant panel as described above, it is easy to install it in the furnace, and a large number of ventilation blocks can be incorporated into the radiant panel with a simple structure so that the ventilation blocks do not fall off.

The ceramic breathable blocks that make up the radiant panel generally exhibit a high blackness value. For example, silicon carbide and cordierite have a blackness of 0.9 to 0.95 and about 0.8, respectively, and by making them into a honeycomb-like breathable block, the former becomes an almost completely black body, and the latter has a blackness of 0. .9~0.
It becomes 96. By using the radiant panel of the present invention in the heating furnace, the heat of the high-temperature gas is transmitted to the heated object with high heat transfer efficiency, and there is also little heat dissipation from the furnace wall (by lowering the temperature of the exhaust gas and It can be discharged to

The radiation panel of the present invention is suitable for heating furnaces that heat steel materials, etc.
It is easy to adopt. Further, by using the radiant panel of the present invention, the following excellent effects can be obtained.

(1) There is less heat dissipation from the ceiling of the furnace, and if a reflector is provided, this effect will be more pronounced.

(2) The size of the furnace can be reduced by improving heat transfer efficiency. In addition to reducing the installation area of the furnace, the ceiling height of the furnace can also be lowered since there is no need to increase the thickness of the gas.
Not only fuel consumption but also furnace construction costs can be reduced.

(3) By providing multiple rows of radiant panels, they also function as partition walls within the furnace, making it possible to adjust each part of the furnace to the required optimal temperature distribution at each interval between the radiant panels. Not only can heating efficiency be improved, but also a preferable temperature history required for heating an object to be heated can be easily achieved.゛

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of the radiant panel of the present invention, and FIGS. 2 and 3 are lines AA and B-- in FIG. 1, respectively.
It is a sectional view taken along the line B. Agent Ken Tsugamura Part 1-゛・

Claims (2)

[Claims] (1) A radiant panel that can be suspended from the ceiling of a heating furnace that heats objects to be heated with a flow of high-temperature gas, and the radiant panel is made of ceramic material that has a plurality of hanging rods, a slip prevention material, a bottom plate, and a large number of ventilation holes. It has a plurality of air permeable blocks made of aluminum, the slip prevention material is arranged between the air permeable blocks, and the hanging rod is inserted through the end of the bottom plate and suspended. Features a radiant panel. (2) The radiant panel according to claim 1, wherein the ceramic breathable block is a ceramic honeycomb.